Applications of micro-nanobubble and its influence on concrete properties: An in-depth review

Abstract

Micro-nanobubbles (MNBs) are tiny bubbles of water used in various industries. The production methods and properties of concrete containing MNBs and the applications of MNBs in different industries are reviewed. Then, the effect of MNBs on the properties of fresh and hardened concrete is described. Next, we assessed the advantages and disadvantages of using MNBs in different types of concretes, environmental and economic impact, and research gaps in the concrete containing MNBs. Even though the presence of MNBs in concrete has an undesirable effect on workability and rheology parameters, the results of workability are in the range of the European Guideline for Self-compacting Concrete regulations and the British Standard for conventional concrete. In contrast, using sulfo-aluminate cement instead of Portland cement and MNBs in concrete improves rheological characteristics. The review also shows that MNBs improve the mechanical properties of concrete by up to 31% for compressive strength, 10–20% for tensile, and 3–34% for flexural strength. Furthermore, concrete containing MNBs has performed better than conventional concrete in terms of durability properties such as electrical resistivity, ultrasonic pulse velocity, chloride penetration resistance, and resistance to freezing–thawing cycles (F-T cycle). MNBs in concrete reduce the porosity by 17% and decrease the size of the holes. Water absorption of MNB concrete at 28 days decreased by 20%, and chloride permeability reduced by 20%. MNBs in concrete help to develop the resistance of cement-based materials improve the elastic modulus at early ages and increase the ability to resist cracking, which can reduce the crack width. Still, it is necessary to carry out more experimental work for workability and durability, especially for SCC. Even though a few studies indicate a slight impact on the environment, environmental and economic effects, and production challenges need more investigations.

Full text

Review Article
Abolfazl Soleymani Tushmanlo, Hamid Soleymani Tushmanlo, Gholamreza Asadollahfardi*, and
Yeganeh Mahdavi Cici
Applications of micro-nanobubble and its
influence on concrete properties: An in-depth
review
https://doi.org/10.1515/ntrev-2024-0068
received November 19, 2023; accepted July 10, 2024
Abstract: Micro-nanobubbles (MNBs) are tiny bubbles of
water used in various industries. The production methods
and properties of concrete containing MNBs and the appli-
cations of MNBs in different industries are reviewed. Then,
the effect of MNBs on the properties of fresh and hardened
concrete is described. Next, we assessed the advantages
and disadvantages of using MNBs in different types of con-
cretes, environmental and economic impact, and research
gaps in the concrete containing MNBs. Even though the
presence of MNBs in concrete has an undesirable effect
on workability and rheology parameters, the results of
workability are in the range of the European Guideline
for Self-compacting Concrete regulations and the British
Standard for conventional concrete. In contrast, using sulfo-
aluminate cement instead of Portland cement and MNBs in
concrete improves rheological characteristics. The review
also shows that MNBs improve the mechanical properties
of concrete by up to 31% for compressive strength, 10–20%
for tensile, and 3–34% for flexural strength. Furthermore,
concrete containing MNBs has performed better than con-
ventional concrete in terms of durability properties such as
electrical resistivity, ultrasonic pulse velocity, chloride pene-
tration resistance, and resistance to freezing–thawing cycles
(F-T cycle). MNBs in concrete reduce the porosity by 17% and
decrease the size of the holes. Water absorption of MNB con-
crete at 28 days decreased by 20%, and chloride permeability
reduced by 20%. MNBs in concrete help to develop the resis-
tance of cement-based materials improve the elastic modulus
at early ages and increase the ability to resist cracking, which
can reduce the crack width. Still, it is necessary to carry out
more experimental work for workability and durability, espe-
cially for SCC. Even though a few studies indicate a slight
impact on the environment, environmental and economic
effects, and production challenges need more investigations.
Keywords: micro-nanobubble, workability, durability, mechan-
ical properties, heat of hydration, environmental pollution, eco-
nomic evaluation
1 Introduction
Nanotechnology has been considered a pivotal technology
in recent years, and today, countries around the world are
trying to be leaders in the development of science and
technology and offer solutions for various social and eco-
nomic problems. Nanotechnology is focused on as a core
technology that can solve global energy resource and demand
issues and can contribute to economic goals such as over-
coming productivity loss, creating industry convergence,
and increasing employment. Therefore, many countries are
making huge investments in the development of nanotech-
nology at the national level [1]. One of the nanotechnology
methods that has recently received attention is micro-nano-
bubble (MNB)-based water methods. Microbubble has one of
the physical and chemical properties that are used in water
treatment [2–5]. Micro-nanobubbles of water have various
applications in wastewater treatment. The processes of aera-
tion, disinfection, flotation, and advanced oxidation are the
most commonly used methods in wastewater treatment that
utilize micro-nanobubble technology. Studies have shown that
using micro-nanobubble technology in wastewater treatment
can increase the efficiency of pollutant removal, reduce the
size of facilities, shorten operation times, and lower the cost
of operation and maintenance in water treatment plants [3].
Abolfazl Soleymani Tushmanlo: Civil Engineering Department, Iran
University of Science & Technology, Tehran, Iran,
e-mail: soleymani_a@civileng.iust.ac.ir
Hamid Soleymani Tushmanlo: Civil Engineering Department, Kharazmi
University, Karaj, Iran, e-mail: soleymanihamid0@gmail.com

* Corresponding author: Gholamreza Asadollahfardi, Civil
Engineering Department, Kharazmi University, Karaj, Iran,
e-mail: fardi@khu.ac.ir
Yeganeh Mahdavi Cici: Architecture Department, Azad University,
Eslamshahr City, Iran, e-mail: y_mahdavi_cici@yahoo.com
Nanotechnology Reviews 2024; 13: 20240068
Open Access. © 2024 the author(s), published by De Gruyter. This work is licensed under the Creative Commons Attribution 4.0 International License.

In recent years, the use of nano-scale additives, such as
nano-silica, nano-alumina, nano-titanium, and nano-carbon
tubes, has become very common in conventional concrete to
improve its mechanical characteristics [6]. They are used to
improve the mechanical properties and durability para-
meters of concrete due to the problems of being expensive,
inaccessibility, and transportation issues, and because the
particles of these materials are very hard, fine, and round
due to their nano dimensions, they have negative environ-
mental and health impact and are very dangerous for
human health.
Recently, a new micro-nano additive called micro-
nanobubble water (MNBW) has been used in the produc-
tion of mortar and concrete in addition to being used in the
water and wastewater industry. These MNB structures are
water-to-bubble additives that do not add a new chemical
composition to concrete [7,8]. Among nanomaterials, MNBs
can be used as a supplement or a substitute for water used
in concrete [9]. Nanobubbles are an important topic in the
industry. Various companies in Canada, Japan, South Korea,
the United States, and others have claimed to have produced
nanobubbles with unique methods [10].
Given that the mechanical strength and durability
of different types of concretes significantly impact their
lifespan and that large amounts of concretes are used
in constructing various buildings worldwide, enhancing
mechanical strength and durability using MNBW in concrete
can reduce resource consumption. By increasing the lifespan
of concrete, this approach supports environmental sustain-
ability. This article reviews the use of MNBW across various
industries and examines its effects on the workability,
mechanical strength, and durability of different types of con-
cretes. In addition, it discusses further research proposals
concerning the environmental and economic impacts, pro-
duction challenges, and the overall impact of using MNBW.
2 Introduction of MNBs
MNBs are small bubbles. Their diameter is 1–100 µm and less
than 1 µm (these numbers may vary differently in previous
studies [11,12]) and have been studied for various applica-
tions. Figure 1 shows the main differences between large
bubbles, microbubbles (MBs), and nanobubbles (NBs). In
MBs, the bubble size gradually decreases and then collapses
due to long-term stagnation and dissolution of internal gases
in the surrounding water, while NBs remain stable for
months and do not collapse suddenly. It has been found
that the interface of NBs consists of tight hydrogen bonds,
which in turn leads to the reduction of diffusion of NBs and
helps to maintain sufficient kinetic balance of NBs against
high internal pressure [5,9,13,14].
However, small bubbles between these two diameters
are usually called MNBs. Therefore, MNBs are very small
cavities containing gas in an aqueous solution, which are
formed by the aggregation of nanoparticles and molecules
inside a protective layer. Researchers have noted that
MNBs have the following six superior properties over con-
ventional (or ordinary) bubbles [4].
•Large special area
•Longer stability in water
•High mass transfer efficiency
•Spontaneous production of free radicals
•MNBs can self-pressurize and dissolve in water
•The applications of MNBs in environmental pollution
control have been widely considered
Production of MNBs can be produced in different
ways. Before introducing specific methods, it is important
to note that the demand for their production is largely
application based, and validation of whether the products
are gas bubbles is sometimes left out because of its game-
changing potential. For scientific research on Bulk nano-
bubbles, it is vital to ensure this issue [15].
Extensive research has been done on the production
methods of MBs and NBs, and different methods have been
used for their production in different sources and for dif-
ferent uses. Although they have investigated the techni-
ques or generators of MBs in their studies, most of the
techniques or generators are such that by setting different
working parameters, and they can also produce NBs, which
are presented in Table 1 [11,16].
As outlined in Table 1,nanobubbleproductionmethods
are categorized into four groups: flowing liquid usage,
without accompanying liquid flow, by polymer, and low
Figure 1: Difference between big bubble, micro bubble, and nano-
bubble [5].
2Abolfazl Soleymani Tushmanlo et al.

power generation techniques. Each category encompasses
various types. For instance, within the “by polymer”cate-
gory, three distinct methods are listed, with details provided
in Table 1 for each method.
According to Harris et al. [11], the nanobubble produc-
tion methods can be simplified into four categories based on
their working principles: hydrodynamic method, acoustic
method, mechanical agitation method, and electrochemical
method. The hydrodynamic method operates on the prin-
ciple of cavitation, while the acoustic and electrochemical
methods utilize sound waves and electrolysis, respectively.
The mechanical agitation method involves liquid stirring
and bubble production, which depend on the speed of the
mixer or homogenizer.
Another method for producing nanobubbles is the col-
lapse production method, which involves the use of ultra-
sonic waves or shock waves to induce extreme pressure
changes. To prevent bubbles from coalescing and disap-
pearing, anticoagulant agents are often necessary. In cer-
tain cases, such as with rotary rotations or ultrasonic
waves, a rapid decrease in pressure to a level below the
saturated vapor pressure causes the liquid to boil and dis-
joints the air, resulting in the separation of bubbles, though
this process may also lead to bubble disintegration [17].
In the shearing production method, bubbles are gen-
erated through gas shearing within a turbulent flow in a
gas–liquid mixture. This turbulence is often created using
a tube venturi or by inducing rotating flow, such as
shaking a bottle containing a mixture of gas and liquid.
This method is effective in producing bubbles [17]. In the
shearing production method, bubbles are generated through
gas shearing within a turbulent flow in a gas–liquid mixture.
Turbulence is induced by means such as a tube venturi or
rotating flow, including the agitation caused by shaking a
bottle containing a gas–liquid mixture, all falling under this
category. In the pressurized dissolution production method,
gas is dissolved into the liquid under the pressure of a com-
pressor. Once the liquid reaches supersaturation, the pres-
sure in the tank is rapidly released, returning the liquid to
normal pressure. This sudden change separates the super-
saturated gas, resulting in bubble formation [17]. Microporous
production method: Bubbles are generated as pressurized gas
flowsthroughporousmaterialssuchasglassormetalplates
with micro-scale open pores, allowing free connection with
the fluid. Alternatively, a small-diameter expanded glass tube
submerged in the liquid can also produce bubbles. Solid trap-
ping production method: Bubbles form when gas becomes
trapped in ice or solid particles dissolve in a liquid.
Chemical reactions production method: Molecular nano-
bubbles (MNBs) are generated as a result of some of the gas
produced at an electrolysis electrode undergoing transforma-
tion [17].
Generally, cavitation is defined as the formation of
small bubbles that are filled with gas or vapor or a combi-
nation of both, and the subsequent activities are growth,
disintegration, and return to the original state in liquids.
Depending on the gas forming the bubble, cavitation can
be divided into two categories: vapor and gas (Table 2)
[18,19].
As depicted in Table 2, the cavitation mechanism for
nanobubble production is categorized into two types: sur-
face tension and energy storage. The surface tension method
itself is further divided into two categories: hydrodynamic,
which involves changes in liquid flow pressure due to
system geometry, and acoustic, which relies on acoustic
cavitation induced by ultrasound waves applied to liquids.
To elaborate on the hydrodynamic method within the surface
tension category, which operates based on changes in liquid
flow pressure due to system geometry, a venturi tube can be
utilized. This method has been applied in coal column flotation
using a venturi tube to generate nanobubbles. For more
Table 1: Classification of MNB production methods [16]
Num. Category Type
1 When flowing liquid
is used
Spherical body in a
flowing tube
Rotary liquid flow type
Static mixture type
Venturi type
Ejector type
Multi-fluid mixture device
Pressurized dissolution type
2 Without accompanying
liquid flow
Rotary gas flow type
Porous membrane type
Electrolysis type
Vapor condensation system
Porous mullet ceramics
technique
3 By polymer Emulsion solvent vaporization
Cross-linking polymerization
Atomization and
reconstitution
4 Low-power generation
techniques
Flow focusing technique
Microchannel technique
Ultrasonic systems
Micro-bubble technique
Heating of carbon nanotube
Laser induction breakdown in
water
Using organic membranes
Shear flow in pipe and slits
Generation of single MNB
Fiber optic tips coated with
nanoparticles
Using micro-nanobubble water in concrete 3

comprehensive information on the cavitation mechanism,
readers are directed to previous studies [18,19]. Figure 2
illustrates a schematic diagram of the cavitation venturi
tube, and Figure 3 shows a schematic diagram of a flotation
column with a static mixer and a cavitation valve.
Figure 3 depicts a schematic representation of a 5.08 cm
open floating column standing at a height of 250 cm, out-
fitted with a static mixer and an aeration tube designed for
the production of pico-nanobubbles. The slurry feed is intro-
duced into the feed tank, followed by the addition of
an optimal quantity of collector and a foamer to prepare
the mixture, facilitated by a ring and circulation pump
[20]. Then the feed slurry enters the upper part of the flota-
tion column. Air, fresh water, and recirculated tailings are
sequentially mixed by a static mixer and a vent pipe before
being injected into the bottom of the flotation column. The
flotation column is also equipped with a washing water
device, which is used to drain very fine mineral particles
inside. A tailings discharge section has also been added to
the floating column. This section is used to improve the
mixing of bubbles and solids, and by recirculation, about
a third of the solids have been added to the floating column.
A static mixer is used to produce fine bubbles, and a static
mixer is also used to improve the contact between bubbles
and solids [20].
2.1 Stability
The stability of MNBs refers to their ability to maintain
their shape, size, and properties over time. Several factors
influence the stability and reactivity of NBs, including
bubble size and characteristics, zeta potential, and surface
properties. In addition, the properties of NBs are influ-
enced by the solution’s characteristics, the type of gas
used, and the energy inputted into the system for nano-
bubble production. Solution properties such as tempera-
ture, pressure, ion type, ion concentration, pH, presence
of organic substances or impurities, presence of surfac-
tants (surface activators), and the concentration of satu-
rated gas have a significant impact on the characteristics
of NBs. Moreover, the specific gas employed and its solu-
bility and reactivity can also affect the bubble’s properties
[18,21–23].
2.2 Characteristics of MNBs and their
controlling factors
2.2.1 Bubble size
The size of air bubbles is the most important characteristic
associated with them. Generally, MBs are bubbling whose
diameter is about micrometers, but in studies, their dia-
meter ranges are different. Bubbles can be classified into
macro bubbles, MBs, sub-micron bubbles, or NBs corre-
sponding to ordinary or big bubbles, and fine and ultrafine
bubbles based on their size [11,16].
Macro bubbles are larger and more influenced by buoy-
ancy and speed, which makes them prone to instability
during measurement. On the other hand, longer stability
time in liquid makes MNB characterization more feasible.
It is worth noting that the size of the bubbles is dynamic and
by merging or shrinking, the bubbles can transform into
each other [11,24]. In Figure 4, the size distribution of
MNBW bubbles is depicted based on three measured para-
meters: volume, number, and intensity.
The size dispersion of MNBs was assessed using the
nanoparticle size analyzer tool on specimens aged 1 day,
employing the cumulant analysis method that considers
three parameters: volume, number, and intensity of speci-
mens. This analysis was conducted at the central laboratory
of Ferdowsi University of Mashhad in Iran. Figure 4a–c
Table 2: Classification of cavitation mechanism [18,19]
Num Type Category Mechanism
1 Surface tension Hydrodynamic method Variation in the pressure of liquid flux due to system geometry
2 Acoustic method Acoustic cavitation produced by applying ultrasound to liquids
3 Energy storage Particle method Passing high-intensity light photons in liquids
4 Optical method Short-pulsed lasers focused into low absorption coefficient solutions
Figure 2: Schematic diagram of cavitation venturi tube [20].
4Abolfazl Soleymani Tushmanlo et al.

depicts the size dispersion of MNBs based on volume,
number, and intensity parameters, respectively [25].
2.2.2 Mass transfer efficiency
Mass transfer refers to the overall transfer of mass from
one place to another, which is created due to the presence
of a specific driving force in the system. The mass transfer
process involves various phenomena. One of these is the
free diffusion of molecules, which occurs in a laminar fluid
and static medium. This refers to the movement of mole-
cules from an area of high concentration to an area of
low concentration, driven by random molecular motion.
Another phenomenon is mixing and eddy diffusion, which
occurs in turbulent fluid. Finally, the mass transfer also
includes the transfer of mass between gas and liquid phases.
This phenomenon is often seen in processes like absorption
or stripping. These different phenomena play an important
role in various industrial processes and natural phenomena,
contributing to the overall understanding of mass trans-
port [11].
2.2.3 Bubble rising velocity
Bubble’s behavior in liquid solutions is greatly influenced
by a parameter called the rate of increase. The physical
characteristics of the liquid play a significant role in deter-
mining the growth rate of MBs. MBs have a very low
Reynolds number (approximately Re ≤1) because of their
small size. As a result, these bubbles behave similarly to
spherical bubbles and occasionally resemble solid spheres,
where the gas–liquid boundary allows for free flow. The
upward velocity of an MNB moving through a liquid is
determined by the balance between buoyancy and drag
forces acting upon it. The growth rate can be mathematically
described using Stokes’law. Hadamard and Rybczynski devel-
oped the Stokes theory to explain the behavior of liquid bub-
bles or droplets [11,16,26,27].
=UρgD
μ18
,
lb
2
where ρ
l
is the density, D
b
is the bubble diameter, μis the
water viscosity, Uis the rate of increase, and gis the grav-
itational constant.
2.2.4 Zeta potential
Zeta potential is a physical property possessed by every
particle in a suspension, and it can be utilized to enhance
and optimize the creation of suspensions and emulsions
[16]. Zeta potential refers to the electric potential difference
between the moving scattering medium and the static layer
attached to the scattering particle. The value of zeta poten-
tial is strongly influenced by the stability of emulsions or
colloids, in both the short term and the long term [11]. In
the case of MNBs, their zeta potential describes their
charge characteristics, which impact their dispersion beha-
vior. In the case of MNBs, their zeta potential describes
their charge properties, which have an impact on the dis-
persion behavior of particles. High absolute values of zeta
potential are suitable for improving MNB stability. When
particles possess a high negative potential, they typically
exhibit a mutual repulsion. Conversely, particles with low
zeta potential lack the necessary force to prevent them
from approaching each other [28]. Many factors affect
the zeta potential of bubbles, such as solution pH, gas, ionic
strength, additive concentration, and temperature. Gener-
ally, increasing the pH will decrease the zeta potential [29].
The zeta potential of NBs is influenced by the gas’sabilityto
generate hydroxyl ions on the bubble’ssurface.Solutions
with high pH, low temperature, and low salt concentration
promote a high negative zeta potential for bubbles. In long-
term experiments, the zeta potential of bubbles tends to
diminish as the bubble size increases [18]. In Zhang et al.’s
research [30], a correlation between the zeta potential of
NBs and their size has been identified, indicating a special
Figure 3: A schematic diagram of a flotation column featuring a static
mixer and a cavitation valve [20].
Using micro-nanobubble water in concrete 5

relationship (Figure 5). It is a graph that shows the changes
in zeta potential for water containing MNBs at the age of
1day.
Zeta potential stands out as a pivotal parameter of
MNBs, playing a crucial role in predicting the stability
of particles within the solvent. The surface zeta potential
of water containing MNBs is assessed using the zeta com-
pact cad instrument. Figure 5 demonstrates the variations
in zeta potential of water containing MNBs at the age of 1
day, spanning from −10 to −40 mV experimented at the
central laboratory of Ferdowsi University of Mashhad in
Iran [25].
2.2.5 Hydroxyl radical
Generally, as bubbles smaller than 10 μm continue to
shrink, the electric charge density of the double layer experi-
ences a rapid increase. When a bubble bursts in an aqueous
solution, the highly concentrated positive and negative
charges rapidly release the accumulated energy, resulting
in the production of numerous free radical ions, including
oxygen ions, hydrogen ions, and hydroxide ions. The hydroxyl
radical, in particular, exhibits strong oxidation properties,
enabling it to oxidize and decompose challenging-to-decom-
pose organic pollutants like phenol. This makes it highly effec-
tive for water treatment purposes. MNBs are capable of gen-
erating free radicals without requiring any external stimuli or
additive agents. However, it is important to note that these
free radicals have a short lifespan. Numerous studies have
been conducted to investigate the effect of free radicals
in water treatment. Experimental findings indicate that the
hydroxyl radical can serve as the primary active oxidant spe-
cies (accounting for 82% of the total) in the decomposition of
butylated hydroxytoluene by ozone MNBs [31–34].
2.2.6 Rheological behavior
Rheology is the scientificfield that investigates how matter
deforms and flows when subjected to external forces. It
can be categorized into two branches: surface rheology
and bulk rheology. In measuring the rheological properties
of a material, it is important to know the flow properties
such as shear stresses and shear rates. The relationship
between shear stress and shear rate is shown graphically
in a flow curve. Fluids can be identified by their flow
curves. Various models –or constitutive equations –have
been developed to idealize flow curves. Six of the most
common constitutive relationships associated with concrete
are shown in Figure 6 [35].
The yield stress and plastic viscosity are the two pri-
mary parameters measured by rheometers when applying
the Bingham model. Equation (1) presents the rheological
equation that defines the Bingham model [9].
=+ ≥τμγτττ  ,
00
·
(1)
where
τ
is the shear stress in Pa,
τ
0
is the yield stress in Pa,
μ
is
the plastic viscosity in Pa.s, and
γ
is the shear rate in 1/s.
Some researchers have recommended the Herschel–Bulkley
(H-B) model (equation (2)) to describe the shear thickening beha-
vior of cementitious mixtures. In this model, the shear thickening
behavior occurs when n>1, and the shear thinning behavior
occurs when n<1. The value of nindicates the degree of shear
thickening response.
Figure 4: The air bubble size distributions of MNBs in water [25]. (a) Air
bubble size distribution in MNBs by volume, (b) air bubble size distri-
bution in MNBs by number, and (c) air bubble size distribution in MNBs
by intensity.
6Abolfazl Soleymani Tushmanlo et al.

=+ ≥τkγτττ  ,
n
00
·
where
τ
is the shear stress in Pa,
τ
0
is the yield stress in Pa,
and
γ
is the shear rate in 1/s. nis the flow index, and kis
the consistency factor in Pa s
n
.
Bingham’s model was modified to describe the shear
thickening and thinning behavior (equation (3)). In this
regard, the shear thickening behavior occurs when c/μ>
0, and the shear thinning behavior occurs when c/μ<0[36
].
=+ + ≥τμγCγτττ  
.
020
·
MNBs primarily due to bubble coalescence and coar-
sening are thermodynamically unstable systems. Previous
research has demonstrated the significance of the rheological
characteristics of the gas–liquid interface in determining the
stability of MNBs [14]. In a study conducted by Shen et al. [37],
the stability and rheological behavior of bubble suspensions
coated with concentrated food emulsifiers were investigated.
MBs were generated using flow concentration, where a food-
grade emulsifier was employed. The emulsifier formed a thin
shell around the MNBs, resulting in their stabilization. The
diameter of the produced MBs ranged from 120 to 200 μmand
could be controlled by adjusting the flow rate of the liquid
and gas phases. To assess the rheological properties of the
MBs suspension, a rotational rheometer was used. Gas reten-
tion in the experimental sample was determined through
weight difference measurements. Shen et al. observed that
MNBs remained stable over time without significant changes
in size. Furthermore, it was discovered that as the shear stress
increased, the viscosity of the system decreased. This observa-
tion suggests that the MNB suspension displayed viscoelastic
properties. The reduction of static yield stress and plastic
viscosity of SCC using MNB water were higher than tap water
with the same amount of superplasticizer, concrete age, and
temperature [9]. Based on convexity in the diagram, shear
thinning behavior was observed in concrete samples with
MNBs. The c/μ(negative) ratio went up by increasing the super-
plasticizer dose. This means increasing the intensity of shear-
thinning behavior by increasing the dosage and potential for
segregation and bleeding [9].
3 Application of MNBs
MNBs find diverse applications across various fields, as
depicted in Figure 7.
As shown in Figure 7, MNBs are utilized in drinking
water and wastewater treatment, groundwater decontami-
nation, and medical engineering, as well as in industrial
sectors like agriculture, fisheries, and food. Table 3 pre-
sents an overview of some specific applications of MNBs.
Figure 5: The variation of zeta potential for water containing MNBs at the age of 1 day [25].
Figure 6: Six common models for determining the rheological behavior
of concrete [35].
Using micro-nanobubble water in concrete 7

Table 3 shows the many applications of medical MNBs:
medical, industry energy systems, sludge treatment, soil
and groundwater remediation, waste water treatment, sur-
face water purification, food industry, flotation, surface
cleaning, and bacteria removal. In the medical field, MNBs
are used to detect tumors in the human body with ultra-
sound imaging. They are also used to treat cancer. MNBs are
used in genetics and are used to diagnose malaria. In the
energy supply system of the industry, using MNBs, they
remove oil and mixed carbon from water and bring eco-
nomic benefits to water use. Also, MNBs are used in solar
energy and are used to remove fine metal oxide particles.
Also, in the presence of MNBs, the paint dries faster. In the
food industry, MNBs are used to increase the yield and
quality of the product by increasing the amount and time
it stays in the soil. It also uses them to destroy microorgan-
isms on the surface of fruits and vegetables.
4 Literature review of using MNBs
in concrete
Nanotechnology, being interdisciplinary in nature, holds
the potential to fundamentally transform the construction
industry by interfacing with the science of concrete. In recent
years, the use of nano-scale additives such as nano-silica,
nano-alumina, nano-titanium, and nano-carbon tubes to con-
ventional concrete to improve mechanical properties has
been very common, but research on the effects of MNBs on
concrete has been limited [7,9].
In the research, the effects of MNBs on fresh concrete
and hardened concrete have been investigated to some
extent. Literature survey indicates the results of various
studies using MNBs in conventional concrete and self-com-
pacting concrete (SCC).
4.1 Literature survey
This section presents the findings from a range of studies
that have explored the use of MNBs in both conventional
concrete and SCC.
Zhang et al. [76] studied the impact of MNBs on the
rheology of concrete, focusing on bubble characteristics
such as size, specific surface area, and distance factor.
The research used 11 different types of air bubble agents
and conducted gray correlation and classification analyses.
Their findings suggest that bubble characteristics play a
more important role in concrete rheology than air content
alone. Smaller bubbles (10–200 µm) lead to a greater
improvement in concrete slump and yield stress, as they
distribute more evenly in the mortar, enhancing the bal-
ling and lubrication effect. Larger bubbles (beyond 200 µm)
have less influence on cohesion. Classification analysis indi-
cated that smaller bubbles (10–600 µm) result in greater
slump increases compared to larger bubbles (1,600–600
µm). Overall, the research highlights the importance of
bubble size and distribution in optimizing the rheological prop-
erties of fresh concrete. The presenceofbubblesinthemortar
improves the flow and rheological properties of fresh concrete
by uniformly distributing small bubbles in the mortar. These
Figure 7: Applications of MNBs [38–45].
8Abolfazl Soleymani Tushmanlo et al.

Table 3: Applications of MNBs
Field Application Ref.
Agriculture Water treated with MNBs in agriculture improves the physiological and biological conditions of the
soil by increasing aerobic microorganisms, which has a positive effect on plant growth
[32]
NB water reduces CH
4
diffusion and arsenic dissolution through oxidative modification of redox
conditions in flooded soil
[46]
MNBs accelerate metabolism in animal and plant species [47]
Using MNBs in hydroponic solutions to clean and sterilize irrigation water (ozone bubbles) [32]
The high oxygen content and permeability of MNBs cause plant root growth, shorten the growth
cycle, and thus improve the economic yield
[48]
The use of MNBs kills bacteria, removes harmful substances and odors from water, and improves
the freshness and taste of fruits
[32]
Removal of residual pesticides in vegetables [49]
MNBs are used for biological and weed control [50–52]
MNBW improves the seed germination rate [53–55]
Aquaculture and fisheries MNBs improve blood flow and branchial respiration of fish [50,54]
Application of treated MNBW to aquatic plants and fisheries significantly increases growth by
improving nutrient uptake
[56]
Cellular biological MNBs are used in fermentation [57]
Energy and carbon neutrality MNBs play an essential role in the production and use of hydrogen [14,58]
It was found that MNBs are a suitable option for increasing oil recovery [14,59]
Medical MNBs are used to detect tumors in the human body by ultrasound imaging [60]
MNBs are used to treat cancer patients in different forms and methods [61]
MNBs are used in the treatment of dentistry and conditions affecting the teeth and gums
(placement, restoration, and extraction)
[62,63]
MNBs are used in genetics [64]
MNBs are used to diagnose malaria [65]
Industry energy systems MNBs remove mixed oil and carbon from water and provide economic benefits for water reuse [66]
MNBs are used in solar energy. [67]
Removal of fine metal oxide particles [68]
To disinfect sediments using ultrasound waves with ozone MNBs [69]
In the presence of MNBs, the paint dries faster [70]
Sludge treatment MNB can significantly improve the quality of aquaculture water, which is mainly affected by
aquaculture sludge
[4,71]
Soil and groundwater
remediation
MNBs can greatly enhance bioremediation by accelerating the oxygen transfer process. [4]
Wastewater treatment The use of MNBs provides an environmentally friendly method for wastewater treatment through
the formation of free radicals
[3]
MNBs is a simple, efficient, low-cost, and environmentally friendly technology for removing oil
pollutants and fine particles from wastewater
[4]
The possibility of improving underground water using micro and ozone bubbles [28]
Removal of chlorinated organic compounds from wastewater [72]
Surface water purification MNBs produced from air and nitrogen can increase the activity of microorganisms and/or bacteria
under anaerobic and aerobic conditions to accelerate the biodegradation of pollutants in water and
sediment. As a result, through aeration with MNBs, water purification can be achieved more
effectively.
[4]
Food industry The breakdown of MNBs producing hydroxyl radicals can accelerate oxidative degradation. [52]
Increase in gas content in solution and retention time [28]
Increasing the yield and quality of the product by increasing the amount of oxygen and the
retention time in the soil
[52,71]
Killing microorganisms on the surfaces of fruits and vegetables [52]
Flotation MNBs are used to effectively improve the flotation efficiency of coal, phosphate, and sand
chalcopyrite.
[14,73]
Surface cleaning MNBs are environment-friendly surface cleaning agents [14,74]
Bacteria removal MNBs are effective in removing infectious pathogens in contaminated water [75]
Using micro-nanobubble water in concrete 9

bubbles fill spaces between aggregates and cement particles,
trapping free water and releasing it to form concrete lubrica-
tion. The introduction of bubbles thickens the mortar layer,
increasing the distance between coarse aggregates, and redu-
cing collision and frictional resistance, which significantly
enhances concrete’soverallperformance.
Grzegorczyk-Frańczak et al. [77] examined the impact
of using MNBs containing O
2
and O
3
gases in concrete. The
study found that MNBs reduced concrete porosity, resulting
in increased bulk and specific density, with a more pro-
nounced effect from O
2
bubbles. Concretes with MNBs, par-
ticularly those with ozone, had lower water absorption and
higher compressive strength at 14 and 28 days. After 150
freeze–thaw cycles, concrete with O
2
MNBs showed 44%
less weight loss than the reference concrete, while O
3
MNBs demonstrated even less weight loss. The reduction
in compressive strength was less for concretes with MNBs
than for reference concrete. In addition, concretes with
MNBs had higher thermal conductivity and lower total sur-
face voids and apparent density, with the best performance
seen in concretes with O
3
MNBs. Arefiet al. [78] investigated
the effect of adding MNBs to water before mixing it with
aggregate and cement. The results showed that concrete
with MNBs had lower workability, with a slump about
10 mm less than conventional concrete. MNBs led to early
or immediate hydration and lower temperature changes
during setting. The setting time was reduced, and the 7-
and 28-day compressive and tensile strength of concrete
with MNBs were higher than those of conventional concrete.
Grzegorczyk-Frańczak et al. [79] studied the impact of
MNBs of different gases (O
2
,O
3
, and CO
2
) on the physical
and mechanical properties of lime-cement mortars. They
found that adding MNBs decreased the workability of fresh
mortar, especially with CO
2
MNBs. Higher replacement
percentages of MNBs also led to a greater decrease in work-
ability. Concretes with 100% MNB replacement had higher
specific densities and turbidity than those with 50% replace-
ment. Volumetric density increased with CO
2
but decreased
with O
2
and O
3
MNBs. The highest compressive strength
after 28 days was achieved with the 50% O
2
mortar, showing
a 31% improvement compared to the reference sample. Flex-
ural strength generally increased in most mortars after 56
days, ranging from 8.3 to 34% higher than the reference
sample, except for a 2.6% decrease in the 50% O
3
mortar.
Asadollahfardi et al. [80] replaced drinking water with
MNBs and metakaolin as mineral substitutes in concrete. This
change accelerated the hydration process and increased the
28-day compressive strength by 8.82 and 13.2% for 50 and
100% MNB replacements, respectively, although these gains
were slightly reduced over 90 days. Tensile strength also
improved by 10–19% with MNBs, while 42-day flexural
strength rose by 3.97 and 5.7%. Water absorption was sig-
nificantly reduced at 28 days and continued to decrease
slightly at 90 days. The 28-day rapid chloride permeation
test (RCPT) showed that 50% MNB replacement greatly
reduced chloride penetration, with a slight increase at 90
days. Replacing water with MNBs also increased the con-
crete’s electrical resistance. Mohsen Zadeh et al. [81] inves-
tigated the impact of using pozzolans and MNBW in concrete
mixtures. Replacing 50% and 100% of water with MNBs
increased the 28-day and 90-day compressive strength.
The 28-day tensile strength increased by 10 and 19.6%
for 50 and 100% MNBs, respectively, while the 42-day
flexural strength increased by 2.85 and 5.48% with 50
and 100% replacements. Water absorption decreased signifi-
cantly at 28 days with reductions of 16 and 20% for 50 and
100% MNBs, respectively, and continued to decrease slightly
at 90 days. Chloride permeability also reduced significantly at
28and90dayswith50and100%MNBs.Inaddition,MNBs
reduced the pH of concrete.
Yahyaei et al. [9] studied the impact of MNBs on SCC.
They found that adding MNBs slightly reduced slump flow
and increased V funnel time, leading to faster slumping.
MNBs also improved permeability and increased the J-Ring
test value, but had a little effect on L-box and air percentage
results. MNBs enhanced compressive strength but reduced it
in mixtures with silica fume. MNBs improved concrete’s
impermeability and specific electrical resistance. SEM results
showed well-distributed MNB particles under 10 µm. MNB
size under 50 nm affected shrinkage but not compressive
strength. Kim et al. [82] conducted research in which they
used water containing high concentrations of hydrogen
nanobubbles as mixing water for cement mortar. They
explored the effects of substituting regular mixing water
with hydrogen nanobubble water (HNBW) in proportions
of 40 and 80%. The nanobubbles used in the study had
diameters of less than 200 nm.
TGA is the most widely used method to determine the
degree of hydration. In this research, according to Bhatty’s
method [76], temperature ranges and types of hydrations
were determined. This approach identifies cement hydrates
by measuring the weight loss that occurs over a specific
temperature range. They concluded that the flexural
strength of cement mortar increases with the replacement
of nanobubbles. As the amount of substitution increases, the
bending strength also increases. Nanobubble has not had a
significant effect on the compressive strength of mortar for 3
and 7 days. While the 28-day compressive strength has
increased by 6.5 and 11% for 40 and 80% replacement,
respectively. Furthermore, by comparing the XRD patterns
of cement paste, the pastes made with 0, 40, and 80% sub-
stitution of hydrogen nanobubbles had similar patterns.
10 Abolfazl Soleymani Tushmanlo et al.

With increasing nanobubble concentration, although there
was no difference in the type of crystalline phase, a slight
difference in the peak intensity of scattered X-rays was
observed. As a result, it was confirmed that the new crystal-
line phase was not formed by the nanobubbles. In addition,
it was confirmed that the reaction speed of nanobubbles
with cement particles affects the improvement of mortar
strength. Moreover, TGA test results show that:
•During initial heating (28–105°C), the weight loss of all
samples was similar.
•As the concentration of bubbles increased during heating
up to 1,000°C, the weight loss increased gradually.
•In each temperature range, a sudden change in the
“weight-loss-time”curve occurs.
•The amount of total hydrate of cement (C–S–H, Ca (OH)
2
,
CaCO
3
) increases with the increasing concentration of
hydrogen nanobubbles. The increase of CaCO
3
for 40
and 80% substitution is almost similar, and the increase
in the other two hydrates causes a difference for these
two substitution percentages.
•With the increase in the concentration of nanobubbles,
the increase in C–S–H is greater, and this means that
according to the bubble concentration,
•C–S–H (3CaO·SiO
2
·3H
2
O) developed more actively than
CH(Ca(OH)
2
).
•The hydration and pozzolanic reactions are continuously
promoted by hydrogen nanobubbles, leading to an overall
increase in the degree of hydration, which, in turn, improves
the mechanical strength of the cement mortar.
•Increasing nanobubble concentration increased the for-
mation of Ettringite and C–S–H crystals at the same treat-
ment dose.
Wan and He [83] investigated the impact of MNBs and
an aluminum sulfate nonalkaline accelerator on the volu-
metric stability of cement-based materials (shotcrete) over
180 days. The addition of MNBW significantly reduced
shrinkage deformation, including self-shrinkage and drying
shrinkage, by over 10% in 28 days and about 6.5% in 180
days. MNBW improved internal moisture, reduced porosity
by 16.9%, and decreased average pore size by 22.9%,
increasing density. MNBs also lowered surface tension and
negative capillary pressure, reducing the risk of shrinkage
and cracking. MNBW enhanced early resistance develop-
ment and improved elastic modulus, minimizing the crack
width and increasing the ability to resist cracking.
Sheikh Hassani et al. [25] examined the effects of using
water with MNBs on cement mortar and concrete at different
ages and water-to-cement (W/C) ratios. MNBW slightly
increased concrete temperature and pH while boosting water’s
electrical conductivity and turbidity. It also shortened the
initial and final setting times of cement pastes. MNBW reduced
the flowabilityofcementmortarby18.75%anddecreased
slump by 50%. MNB concrete showed lower slump loss over
time and increased compressive strength by 16% at 7 days and
7% at 28 days. MNBs enhanced early hydration product forma-
tion, leading to less strength increase beyond 28 days. Scanning
electron microscopy revealed well-formed crystals and dense
solid masses with fewer micropores in MNB concrete.
Lan et al. [84] studied the impact of water-containing
nanobubbles and nano silica on air content, freeze–thaw
resistance, and hydration in cement materials at different
air pressures (0.4, 0.7, and 1 atmosphere). They used ana-
lytical techniques like SEM, XRD, and TG-DSC to evaluate
hardened cement paste samples. All nanobubbles were
smaller than 90 nm, with an average size of 45 nm. Nano-
bubbles increased the solidified air content in cement
paste by 12.3–22% across different pressures, reduced the
distance factor, and varied cavity diameter and density
depending on pressure. Nanobubble water accelerated
cement hydration, increasing calcium silicate hydrate and
other cement hydration products. SEM examination showed
smoother, more compact pore walls in cement paste with
nanobubble water. Compressive strength increased by
0.3–3.9% based on air pressure. Although low pressure
increased weight loss, especially after 50 freeze–thaw
cycles, nanobubble water improved the freeze–thaw resistance
of air-bubbled and nonbubbled samples at low pressure.
Kim et al. [85] investigated the impact of using hydrogen
nanobubbles with high concentrations on the performance,
durability, water tightness, and microstructure of cement mix-
tures. By using osmosis for 40 and 80 min, they increased the
concentrationofhydrogennanobubbles in water, resulting in
more stable states and particle sizes decreasing with longer
osmosis time. This increased concentration of nanobubbles
led to higher compressive strength, especially after 7 days,
though it reduced workability. The higher nanobubble con-
centration also decreased porosity and increased the density
of the mortar, forming a denser cavity structure. The results
showed changes in pore distribution that supported a solid
structure in the cement paste. SEM tests revealed that as
HNBW concentration increased, the internal structure of the
cementpastebecamedenser,withmorehydrationreactions
like ettringite and C–S–H crystal formation. Khoshroo et al.
[86] studied the impact of replacing traditional concrete with
MNBs at 30, 60, and 100% levels on concrete properties. They
found that MNB concrete reduces fluidity due to accelerated
hydration but can be managed by adding a superplasticizer.
MNB concrete has higher density and packing, with higher
replacement percentages leading to greater packing. Compres-
sive strength increased by 6, 9, and 13% at 28 days for 30, 60,
and 100% replacement levels, respectively, due to faster
Using micro-nanobubble water in concrete 11

hydration and improved homogeneity from particle bub-
bles. However, a decrease in compressive strength was
seen at 90 days likely because most hydration occurred
within the first 28 days.
Tayebi Jebeli et al. [87] studied the enhancement poten-
tial of using MNBW as a replacement for waste foundry
sand (WFS) in concrete mixtures. They replaced natural
sand with varying levels of WFS (10–40%) and MNBW
(50–100%) in concrete mixtures. The optimal mixture was
found to be 40% WFS concrete containing 100% MNBW.
Adding WFS reduced slump compared to a reference
sample, especially with MNBW. The sample with 20% WFS
showed the highest increase in compressive strength across
different time points, but higher levels of WFS replacement
led to decreased compressive strength. In general, MNBW
improved compressive strength, particularly at 90 days.
Ultrasonic pulse velocity (UPV) results showed no significant
effect on concrete quality with MNBW, although water
absorption decreased slightly up to 20% WFS replacement.
The study found improved chloride penetration up to 20%
WFS replacement, with no significant changes beyond
this point. SEM tests indicated a reduction in the number
and size of pores with WFS, but cracks on the surface
increased in width with higher WFS levels and in mix-
tures with MNBW.
Lee et al. [88] explored the impact of using nanobubble
water in cement composites, including high-performance
concrete, lightweight cement composites, and high-strength
mortar. The water used contained 7% nanobubbles with an
average size of 750 nm. Results showed that using nano-
bubble water improved the compressive strength of cement
composites compared to those made with regular water, even
with a lower cement ratio. The performance improvement
ranged from 3 to 22%, with the greatest increase (22%) seen
in ultra-high-performance concrete (UHPC). The study also
found that nanobubble water enhanced the workability of
the concrete, especially in UHPC, and attributed the improve-
ment to the small size and high quantity of the nanobubbles,
which interact with silica fume and prevent the ball effect.
Larger nanobubbles, in contrast, tend to float up and disap-
pear from the mixing water. He et al. [89] studied the effects
of MNBs and mineral additives on the performance, dur-
ability, and mechanical properties of C60 concrete. They
found that while MNBs decreased the workability of both
conventional concrete and self-consolidating concrete (SCC),
samples containing MNBW and silica fume exhibited about
4% higher compressive strength. In addition, the penetration
depth of carbonation in samples with MNBs decreased by
about 38%. Frost resistance tests showed a 53% reduction in
mass loss and a 2.9% decrease in the loss of dynamic elastic
modulus during ice melting cycles, indicating that MNBs
improve the durability and mechanical properties of C60
concrete.
Wan et al. [90] explored the cold resistance of shot-
crete concrete with additives and MNBW. They found that
using MNBW reduced the size of concrete pores, increased
density, and improved bonding between paste and aggre-
gate. MNBW enhanced the 28-day compressive strength of
shotcrete concrete more with an alkaline accelerator than
an alkali-free accelerator. MNBW also reduced the loss of
compressive strength due to freezing and thawing, particu-
larly after 200 cycles, where it reduced mass loss by 42.2% in
concrete with alkaline accelerators and 5.4% without. In addi-
tion, samples with normal water showed serious damage
after 200 cycles, whereas those with MNBW maintained their
relative dynamic elastic modulus. Overall, MNBW improved
cold resistance and durability in shotcrete concrete.
Chang et al. [91] used MNBW in the mixing process of
sulfo-aluminate cement (SAC) paste and found that MNBW
enhanced hydration and improved the microstructure of
the cement matrix. SAC paste mixed with MNBW showed
improved mechanical properties compared to paste mixed
with tap water. Compressive strength increased by 23.8%
at 1 day and 14.4% at 28 days, while flexural strength
increased by 16.6% at 1 day and 10.7% at 28 days. MNBW
also reduced the setting time of the cement paste and low-
ered its plastic viscosity. MNBW facilitated earlier and
higher heat release during hydration, and SEM images
revealed a more uniform distribution of hydration pro-
ducts and fewer cracks. MNBW samples had smaller poten-
tial pore sizes and lower porosity, resulting in a denser
cement matrix. The study presents a unique method for
improving the performance of SAC-based materials, which
can benefit various construction projects.
Chen et al. [92] examined the impact of using hydrogen
MNBs on the workability and mechanical properties of
concrete. The study found that adding nanobubble water
improved the flowability and slump of concrete, particu-
larly with higher water-to-cement (W/C) ratios. Concrete
samples with nanobubble water exhibited increased com-
pressive strength, particularly at 3 days (18%), and showed
improvements in water absorption, electrical resistance,
and chloride penetration resistance across different ages.
SEM images revealed higher hydration rates and forma-
tion of hydration products in mixtures containing nano-
bubble water, indicating enhanced performance due to
fewer pores and greater density in the concrete.
Yahyaei et al. [9] evaluated the effect of using micro-
nanobubbles on the rheology of SCC. The results of their
study have shown that the plastic viscosity and yield stress
were higher in samples made with MNBs. In concrete con-
taining MNBs, shear thinning behavior has occurred and
12 Abolfazl Soleymani Tushmanlo et al.

the c/μratio (negative) has increased with increasing
amount of superplasticizer. When the dosage of superlu-
bricant increased from 4 to 5.5 kg/m
3
, the use of MNBs
increased the percentage of air in SCC by 10, 5, and 4.76%.
Chen et al. [92] investigated the effects of using 150 nm
HNBW in cement concrete. They found that HNBW enhanced
workability and mechanical properties of concrete while
maintaining compressive strength even when cement content
was reduced by 10%. HNBW also improved concrete dur-
ability, including better water absorption, electrical resis-
tance, and chloride permeability resistance. SEM imaging
confirmed the improved quality of concrete with HNBW.
The increased workability was attributed to the adsorption
of negatively charged hydrogen nanobubbles on cement
particles, leading to dispersion and cushioning. HNBW can
reduce the need for cement and additives, improving sustain-
ability. The improved mechanical properties and durability
result from the weak alkalinity of HNBW and the generation
of hydroxyl radicals, which promote cement hydration, com-
paction, and reduced internal pores.
Tochahi et al. [93] studied the mechanical properties
and durability of concrete samples with natural meta-
kaolin and zeolite pozzolans mixed with water nano-
bubbles. The samples were cured in both seawater and
standard conditions. At 28 days, the sample with 100%
MNBs cured in seawater showed improvements compared
to the same mixture cured in standard conditions. Specifi-
cally, it exhibited increased compressive strength (6.97%),
tensile strength (12.82%), bending strength (11%), and electrical
resistance (14%). In addition, it showed reductions in water
absorption within 30 min (10.8%) and RCPT results (10.21%).
Considering the mentioned literature reviews, MNBs
improve the mechanical properties of conventional and
SCC. Up to 31% improvement has been reported for the
compressive strength of concrete containing MNBs. The tensile
and flexural strength of MNB concrete also improves between
10–20 and 3–34%, respectively. Concrete containing MNBs also
affects the durability properties, so the porosity of concrete
decreased by 17%, and the size of the voids also decreased. The
28-day water absorption of MNB concrete decreased by 20%,
and chloride permeability also reduced significantly; this
reduction has been reported in some sources up to 67%. The
presence of MNBs in concrete increases the freeze–thaw resis-
tance of concrete. Lan et al. [84] indicated that both NBW
and NS can improve freeze–thaw resistance and mechanical
strength of samples at low atmospheric pressure by acceler-
ating cement. They proved that NBWs and nano-silica can
improve freeze–thaw resistance and mechanical strength of
samples at low cement hydration. Finally, MNB concrete may
be suitable for shotcrete [90] because it reaches acceptable
compressive strength sooner than conventional concrete.
The presence of MNBs in concrete has a negative effect
on workability and rheology parameters. Their presence
reduces the slump flow by 5–10%. Also, the J-ring height
difference and V-Funnel time experienced a slight increase
in SCC. In the investigation of researchers, MNBs have no
noticeable effect on the L-Box ratio. However, the work-
ability of SCC using MNBs is in the range of European
Guidelines for Self-Compacting Concrete (EFNARC) [94]
(2005) guidelines for SCC production.
It is necessary to find types of workability, mechanical,
and durability experiments of MNB concrete that have
been performed in the world to determine the gap in
research. Considering research reported in Table 4 indicates
types of experimental works associated with the work-
ability, mechanical, and durability of MNBs that have been
done up to now.
Table 4 shows the effect of adding MNBs on the per-
formance of conventional concrete and SCC and divides
the effect of adding MNBs on performance into efficiency,
mechanical properties, durability, etc. To evaluate the
workablitiy of concrete, slump flow, J-ring rate, T
50
,V-
funnel time, L-box ratio, U-box ratio, visual stability index
(VSI), air content, static segregation, dynamic segregation is
used. The third column of Table 4 indicates various work-
ability, mechanical and durability tests to evaluate the effi-
ciency of concrete containing MNBs are listed to evaluate
the mechanical properties, compression strength, flexural
strength, tensile strength tests have been used in previous
studies. To evaluate the durability of concrete containing
MNBs, water absorption (volumetric), SEM, RCPT, electrical
resistance, resistance to the freeze–thaw cycle, resistance to
water penetration, UPV, resistance to water penetration,
resistance to chloride penetration (RCMT), carbonation
depth, and impermeability tests have been used more.
According to the British standards (BS) (2019) [95],
there are four classes for the slump of conventional con-
crete, including S1, S2, S3, and S4, which depend on the
type of application of concrete (Table 5). In addition, it
is possible to use a mixture of drinking water and MNBs
in the preparation of concrete, which caused an increase
in slump compared to the use of only MNBs. Finally, if
sufflaminate cement (SAC) is used for MNB concrete,
improves the rheological properties of SAC paste [91] and
environmental impact compared to using Portland cement.
Kanyenze et al. [96] reached contradicting slump outcomes
compared to the work of Arefiet al. [78] that they indicated
an important reduction in flowability (or consistency). They
claimed the difference in outcomes can be attributed to the
consumption of MNB water compared to pure nanobubble
water in this test, which resulted in different water charac-
teristics and the following impacts on concrete.
Using micro-nanobubble water in concrete 13

Table 4: Types of tests performed for MNB concrete
Properties Concrete type Test Ref.
Workability Conventional Slump [25,76,78,79,82,86–89,92]
Initial setting time [9,25,78]
Final setting time [9,25,78]
SCC Slump flow [9]
T
50
J-ring rate [9]
V-funnel time [9]
L-box ratio [9]
U-box ratio
VSI [9]
Air content [9,92]
Static segregation
Dynamic segregation
Mechanical properties Compression strength [9,25,77–82,84–93]
Flexural strength [9,77,79–81,85,91,93]
Tensile strength [9,78,80,81,86,93]
Toughness of concrete
Durability Water absorption (volumetric) [77,80,81,86,87,92,93]
Water absorption (capillary)
UPV [86,87]
RCPT [80,81,86,92,93]
RCMT [87]
Electrical resistance [9,80,81,92,93]
Conductivity
Chloride profile
Resistance to the freeze–thaw cycle [77,84,89,90]
Resistance to water penetration [9]
Abrasion resistance
Resistance to sulfates
Carbonation depth [89]
Impermeability [89]
SEM [9,25,85–87,91,92]
Others Specific density [77,79,82,86]
Bulk density [77,79]
Packing density [86]
Electrical conductivity [25]
Thermal conductivity [77]
Water turbidity [25]
Temperature [25]
pH [25,81]
Other Shrinkage [83]
Surface tension [83]
Fraction [83]
Total cement hydrates (TGA) [86,91]
The thickness of the mortar layer [76]
Porosity (MIP) [77,82,83,90,91]
Bubble diameter (MIP) [82]
Space factor [84,90]
Bubble density [84]
Accelerating the degree of hydration [80,84,85,87,91,92]
The study of Kim et al. [85] discusses cement mortar, the study of Lan et al. [84] about all cement mixtures, and the study of Kim et al. [82] about
cement paste.
14 Abolfazl Soleymani Tushmanlo et al.

5 Study gaps
There are different types of gaps in the use of MNBs in
concrete, including deficit of experimental works, environ-
mental and economic impacts, production challenges, and
inconsistencies in concrete performance. For testing def-
icit, most of the research was done in the mechanical prop-
erties of conventional concrete, and less has been carried
out in SCC. Limited studies have been done in the field of
durability. In the future work, some tests need more work.
Related to environmental impact, number of studies is a
few. As knowledge of the authors, the economics of using
MNBs in concrete has not been studied much so far.
Production challenges and inconsistencies in concrete per-
formance are necessary to work. After that, a written code
of practice is needed.
5.1 Environmental assessment
The life cycle assessment (LCA) has been done by two
methods, the midpoint by use with CML2000 and the end-
point by use with IMPACT2002+, in the CML2000 method,
the category of effects of global warming potential (GWP),
human toxicity, acidification potential (AP), and fresh-
water eutrophication (FE) have been investigated. The
IMPACT2002+method evaluates the results of the Life
Cycle Inventory (LCI) in the form of human health, eco-
system quality, climate change, and natural resources.
Figure 8 shows the damage results on the midpoint of
concrete containing MNBs using the CML2000 method [97].
Figure 8 shows that MNB concrete has caused more
environmental damage in all classes of midpoint effects
evaluated in Taherian’s study than conventional concrete.
MNB concrete emitted 424.17 kg CO
2
eq in the global warming
group, while conventional concrete emitted 386.44 kg CO
2
eq.
In fact, MNB concrete emitted 37.73 kg CO
2
eq more in the
global warming effect category. The total emission of conven-
tional concrete and MNBs is considered equal to 100%, in this
case, conventional concrete has 47.67% and MNB concrete
has 52.33% of pollution emissions. In the floor, the acidifica-
tion effectofconventionalconcreteis0.89kgSO2eqandMNB
concrete is 0.84. Therefore, in this class, out of 100% of the
total emission, 51.45% belongs to MNB concrete and 48.55%
belongs to conventional concrete. Notably, in the midpoint
technique, the most significant disparity in pollution impact
pertains to freshwater eutrophication (FE), indicating a 4.8%
higher impact in concrete containing MNBs compared to
conventional concrete. Conversely, the least disparity in pol-
lution impact is observed in the human toxicity effect class,
with concrete containing MNBs demonstrating only a 2.42%
increase in damage compared to conventional concrete [98].
Figure 9 illustrates the damage outcomes at the endpoint of
concrete containing MNBs using the IMPACT 2002+method.
The utilization of concrete containing MNBs marginally
elevates environmental pollution indicators in both midpoint
and endpoint methods. The total emission of production per
cubic meter of conventional concrete and MNBs is considered
equal to 100% emission and the contribution of each concrete
isshowninFigures8and 9. MNB concrete has released a
DALY value of 0.000142 in the group of damage to human
health, while conventional concrete has released a DALY of
0.000137 pollution into the environment. Therefore, out of
100% of the total damage to human health, 50.90% of the
shareofconcreteisMNBsand49.10%oftheshareisconven-
tional concrete. MNB concrete has caused more damage in all
classes, but its amount is very close to conventional concrete
and does not have a significant difference with conventional
concrete, and adding MNBs to concrete slightly increases the
amount of damage to the environment [98].
In the life cycle assessment using the endpoint method,
the results indicate that the maximum disparity in damage
indicators is associated with the climate change category,
with a difference of 4.68%. Conversely, the least disparity in
the assessment of damage to natural resources is observed
in the production phase, where concrete containing MNBs
emits only 1.02% more emissions compared to conventional
concrete [98]. According to the existing studies of LCA
about concrete containing MNBs, the environmental
effect of MNBs in concrete is negligible. However, more
studies are necessary to determine the impact of MNBs
in concrete in the environment precisely.
Table 5: Slump classification for conventional concrete BSs
Institution [95]
Slump class Slump
value (mm)
Use of concrete
S4 >160 Trench fill
In situ piling
S3 100–150 Strip footings
Poker or beam
Mass concrete foundations
Normal reinforced concrete in
slabs, beams
Walls and columns
Sliding formwork construction
Pumped concrete
Vacuum processed concrete
S2 50–90 Floors and hand-placed
pavements
S1 10–40 Kerb bedding and backing
Using micro-nanobubble water in concrete 15

5.2 Economic assessment
Concrete producers and consumers are mainly looking for
optimal quality in mechanical strength and durability to
save their costs. Considering this issue, the purpose of this
analysis is to find out the economics of concrete production
and compare it with the environmental burden. Also, per-
forming economic analysis in this review is important
because of the strong role of this topic in the construction
industry. Of course, due to the different climatic conditions
in the world and the different levels of access, we cannot
expect to reach an economic balance in the world.
Taherian [98]comparedfive types of concretes including
MNB concrete, conventional concrete, nano-silica concrete,
micro-silica concrete, and geopolymer concrete economically
in international. Figures 10 and 11 show the results of eco-
nomic evaluation and emissions related to global warming
and acidification in Taherian’s study [98].
The calculation of production cost is based on the rates
of the original year. As shown in Figure 10, in the beginning
year, the production cost of 1 cm
3
of geopolymer concrete
had the highest price with a production cost of 1429.322
dollars, but at the same time, by emitting 286.85 kg CO
2
eq, it has emitted less pollution than other concretes and
Global Warming
Potential (GWP) Humans Toxicity Acidification
Potential
Freshwater
Eutrophication
(FE)
Conventional concrete 47.67 48.79 48.55 47.6
MNBs concrete 52.33 51.21 51.45 52.4
45
46
47
48
49
50
51
52
53
Effect(%)
Midpoint
Conventional concrete MNBs concrete
Figure 8: Results on the midpoint of concrete containing MNB using CML2000 method [98].
Human Health Ecosystem Quality Climate Change Natural Resources
Conventional concrete 49.1 49.49 47.66 49.14
MNBs concrete 50.9 50.51 52.34 50.86
45
46
47
48
49
50
51
52
53
Effect(%)
Axis Title
Endpoint
Conventional concrete MNBs concrete
Figure 9: Damage results on endpoint of concrete containing MNB using CML2000 method [98].
16 Abolfazl Soleymani Tushmanlo et al.

has performed best in this respect. After geopolymer con-
crete, nanosilica concrete cost $625,047 per cubic meter
more than other evaluated concretes. MNB concrete with
a cost of $395.48 has the lowest production cost and also
has the best performance in this field by releasing 495.7 kg
CO
2
eq after conventional concrete and geopolymer con-
crete. Micro silica concrete has created the most pollution
in the environment by releasing 605.32 kg CO
2
eq and then
nano silica concrete has released more pollution than
other concretes [98].
Figure 11 shows that the production of microsilica con-
crete per cubic meter has the most damage in the class of
acidification effect on the environment. By introducing 1.55
kg SO
2
eq, this concrete has created more pollution than
other evaluated concretes in Taherian’s study. Meanwhile,
microsilica concrete has a higher production cost than
MNB concrete. The production cost of each cubic meter
of microsilica concrete was 495.7 dollars [98].
Conventional concrete has caused the least damage to
the environment in this index. By releasing 0.84 kg SO
2
eq,
this concrete has brought the least pollution to the envir-
onment, while its production cost is higher than MNBs and
microsilica concrete. As shown in Figure 11, conventional,
MNBs, nano silica, and geopolymer concrete have caused
less damage in the acidification effect layer, while the
production of each cubic meter of MNB concrete had the
lowest production cost and geopolymer concrete had
the highest production cost. A total of 625,047 dollars
are needed to produce each cubic meter of nano-silica
concrete, and in this regard, it was the second most
expensive concrete among the concrete evaluated in
Taherian’sstudy[98].
Taherian stated that the price of materials (fine and
coarse aggregate, cement, MNBs, and other chemical com-
ponents) for concrete containing MNBs in Iran is about 1%
and in the world about 28% less than conventional con-
crete. However, in this work, the cost of producing MNBW
is not taken into account, which will increase the price of
concrete containing MNBs. It seems that more economic
studies are necessary to reach the real price of MNB con-
crete [98].
5.3 Advantages and disadvantages of MNBs
in concrete
MNBs can be useful as a method to improve the properties
of concrete. In concrete with MNB, the thermal stability of
concrete increases, and heat transfers from the walls to the
0
100
200
300
400
500
600
700
0
200
400
600
800
1000
1200
1400
1600
conventional
concrete
Nanosilica
concrete
Microsilica
concrete
Geopolymer
concrete
MNBs
concrete
kg eq
Price (dollers)
Concrete type
Economic assessment
Price kg CO2 eq.
Figure 10: Economic evaluation results and Kg CO
2
eq emissions for concrete types [98].
Using micro-nanobubble water in concrete 17

surrounding environment. MNBs also have sound insula-
tion properties and absorb sound and thus reduce sound
penetration in the structure. In addition, MNBs increase
mechanical properties such as compressive and tensile
strength and show wear resistance. In general, MNBs
reduce the workability of concrete slightly and improve
durability and MNB concretes reduce the setting time
of concrete and help develop the strength of the cement
base material and improve the elastic modulus at an early
age [9,25,77,86,90]. MNBs have disadvantages such as
increasing the cost of making and injecting concrete
and conducting more and more detailed tests to ensure
the properties of concrete and the newness of its manu-
facturing technology. It may decrease with changes in
environmental conditions (such as temperature and humidity)
and reduce the workability properties of fresh concrete [7,99].
The enhancement in mechanical properties and durability of
concrete is attributed to the weak alkalinity of nanobubble
water and the fact that nanobubbles contract and collapse
generating hydroxyl radicals, promoting the hydration
reaction of cement to develop hydration products. This
densifies the concrete structure and reduces internal
pores. Hydrogen nanobubbles, as a nanomaterial, demon-
strate desirable effects for meeting high-performance
concrete requirements [92].
5.4 Limitations in the industrialization of
concrete containing MNBs
One of the challenges of the industrialization of concrete
containing MNBs can be the cost of producing this con-
crete. In addition, the production process of concrete con-
taining MNBs requires complex and precise processes
that have not yet been optimized due to the novelty of
this technology. Another challenge of this concrete is
its durability in the long term, and the useful life of con-
crete containing MNBs requires more studies to be able to
accurately predict its stability and useful life. The supply
of raw materials for the production of concrete con-
taining MNBs may not be easily available in some regions
of the world.
In various studies, some ambiguities have been mentioned
about the basic characteristics of MNBs, including the stability
of bulky MNBs, which needs more research [100]. Moreover,
despite all those advances, the production of MNB with precise
size and concentration control remains a major challenge, par-
ticularly for NB. Addressing this challenge may necessitate col-
laborative interdisciplinary research efforts [14]. Differences in
outcomes may occur due to factors such as bubble fabrication
methods, their lifespan, and stability. The review emphasizes
the need for future iterative experiments with various mixing
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
0
200
400
600
800
1000
1200
1400
1600
conventional
concrete
Nanosilica concrete Microsilica concrete Geopolymer
concrete
MNBs concrete
kg eq
Price(dollars)
Concrete type
Economic assessment
Price kgSO2 eq.
Figure 11: Economic evaluation results and Kg SO
2
eq emissions for concrete types [98].
18 Abolfazl Soleymani Tushmanlo et al.

ratios to reduce random influences and to validate and enhance
the reliability of the results [92]. The existence of stable and
long-lasting NBs has been confirmed by various experimental
studies. However, traditional theoretical models, such as those
based on Epstein and Plesset’s theory, suggest that nanobubbles
should have short lifetimes due to their small size and rapid
dissolution from high Laplace pressure [101]. These models,
initially designed for larger microbubbles (MaBs), may not be
applicable to nanobubbles, which exhibit unique properties like
electrostatic repulsion and stable motion influenced by Brow-
nian motion. This conflict between theory and observation
highlights the need for new models that account for the specific
characteristics of nanobubbles to better explain their existence
and stability. Inconsistencies among reports on NBs’funda-
mental aspects and characteristicscreatechallengesinunder-
standing them. Different studies show varying findings on NBs’
size,stability,andbehavior,whichmayresultfromdifferences
in experimental conditions and methods. These discrepancies
hinder a clear and consistent understanding of NBs and high-
light the need for standardized experimental methods and reli-
able models to accurately predict and explain nanobubble
behavior.
5.5 Future works
The following areas of research are crucial for future work:
1) Due to discrepancies between theoretical models and
observations of MNBs, there is a need to develop models
that define specific properties of MNBs more accurately.
2) Economic analyses of using MNBs in various types of
concrete are necessary to assess cost-effectiveness and
practical applications.
3) Since two-stage concrete (TSC) is environmentally friendly,
energy-efficient, and offers benefits such as low drying
shrinkage, high bonding resistance, a high modulus of
elasticity, and exceptional durability [102–104], it is recom-
mended to study the integration of TSC in MNB concrete.
4) Conducting a LCA using MNBs in different types of con-
cretes is essential for evaluating their environmental
impact and potential pollution.
5) Understanding the long-term effects of MNBs on the
mechanical and durability aspects of concrete is vital
for sustainable development.
6) Testing various mechanical and durability properties is
required, including fracture toughness, elastic modulus,
temperature effects, depth of water penetration, chloride
concentration (28-day measurement from two opposite
sides in percentage), the RCMT, mass loss under elevated
temperature, and temperature impact.
7) In addition, examining the influence of different types
of fibers on the workability, mechanical, and durability
properties of MNB concrete is recommended.
6 Conclusion
In this review, the characteristics of MNBs and their effect
on the properties of fresh and hardened conventional con-
crete and SCC were assessed. Also, a gap in research using
MNBs in concrete is explained. The summary of key points
is as follows:
•MNBs reduce the workability and rheological properties
of concrete, but the workability is in line with the
EFNARC, and the BSs for conventional concrete. In addi-
tion, using SAC instead of Portland cement and MNBs in
concrete improves rheological properties.
•MNBs cause an early start (almost a teapot) of hydration,
which may be useful for shotcrete.
•The presence of MNBs in concrete improves durability
(resistance to chloride penetration,UPV,electricalresistance,
water absorption, depth of carbonation, and increasing the
resistance to the freezing–thawing cycle) and mechanical
properties of concrete, including compressive, tensile, and
flexural strength of concrete.
•The use of concrete containing MNBs causes a slight increase
in environmental pollution indicators. However, more future
work is necessary to understand deeply the impact of MNBs
on the environment.
•Economic studies show that concrete containing MNBs is
cheaper than conventional concrete without taking into
account the cost of producing MNBW, although in gen-
eral, and taking into account all the details of the cost of
producing MNB concrete, more economic studies of MNB
concrete are also vital.
•Due to existing challenges, such as environmental impact,
cost, stability, production challenges, inconsistencies in
concrete performance, useful life, and the newness of
the production technology of this type of concrete and
limited studies in this regard, the industrialization of
this concrete is currently limited.
•In this review, it was found that SCC and tests related to
fresh concrete have been less interesting and the studies
conducted in the field of concrete durability are also very
limited.
Funding information: The authors state no funding involved.
Author contributions: Abolfazl Soleymani Tushmanlo: reviewed
the literature and collected information, and wrote the initial
Using micro-nanobubble water in concrete 19

draft of the article. Hamid Soleymani Tushmanlo: wrote the
article, made corrections during editing, and responded to
comments. Gholamreza Asadollahfardi: edited the article,
responded to reviewers’comments, made corrections,
added new sources for the literature review, supervised
the research, defined the proposal, and managed the project.
Yeganeh Mahdavi Cici: collected data and conducted the
literature review. All authors have accepted responsibility
for the entire content of this manuscript and approved its
submission.
Conflict of interest: The authors state no conflictofinterest.
References
[1] Bae SH, Lim JS, Shin KM, Kim CW, Kang SK, Shin M. The innovation
policy of nanotechnology development and convergence for the
new Korean government. J Nanopart Res. 2013;15:1–15.
[2] Khuntia S, Majumder SK, Ghosh P. Microbubble-aided water and
wastewater purification: a review. Rev Chem Eng.
2012;28(4–6):191–221.
[3] Sakr M, Mohamed MM, Maraqa MA, Hamouda MA, Hassan AA,
Ali J, et al. A critical review of the recent developments in
micro–nanobubbles applications for domestic and industrial
wastewater treatment. Alex Eng J. 2022;61(8):6591–612.
[4] Xiao Z, Aftab TB, Li D. Applications of micro–nano bubble tech-
nology in environmental pollution control. Micro Nano Lett.
2019;14(7):782–7.
[5] Agarwal A, Ng WJ, Liu Y. Principle and applications of microbubble
and nanobubble technology for water treatment. Chemosphere.
2011;84(9):1175–80.
[6] Birgisson B, Mukhopadhyay AK, Geary G, Khan M, Sobolev K.
Nanotechnology in concrete materials: a synopsis. Transp Res
circular. 2012;E-C170.
[7] Sanchez F, Sobolev K. Nanotechnology in concrete–a review.
Constr Build Mater. 2010;24(11):2060–71.
[8] Sheikh Hassani M, Matos JC, Zhang Y, Teixeira E. Concrete pro-
duction with domestic and industrial wastewaters –A literature
review. Struct Concr. 2023;24:5582–99.
[9] Yahyaei B, Asadollahfardi G, Salehi AM. Study of using micro‐nano
bubble to improve workability and durability of self‐compact
concrete. Struct Concr. 2022;23(1):579–92.
[10] Kim S, Kim H, Han M, Kim T. Generation of sub-micron (nano)
bubbles and characterization of their fundamental properties.
Environ Eng Res. 2019;24(3):382–8.
[11] Haris S, Qiu X, Klammler H, Mohamed MM. The use of micro-nano
bubbles in groundwater remediation: A comprehensive review.
Groundw Sustain Dev. 2020;11:100463.
[12] Temesgen T, Bui TT, Han M, Kim TI, Park H. Micro and nano-
bubble technologies as a new horizon for water-treatment tech-
niques: A review. Adv Colloid Interface Sci. 2017;246:40–51.
[13] Tsuge H. Micro-and nanobubbles: Fundamentals and applica-
tions. New York: CRC Press; 2014.
[14] Jia J, Zhu Z, Chen H, Pan H, Jiang L, Su WH, et al. Full life circle of
micro-nano bubbles: generation, characterization, and applica-
tions. Chem Eng J. 2023;471:144621.
[15] Zhou L, Wang S, Zhang L, Hu J. Generation and stability of bulk
nanobubbles: A review and perspective. Curr OpColloid Interface
Sci. 2021;53:101439.
[16] Parmar R, Majumder SK. Microbubble generation and micro-
bubble-aided transport process intensification—A state-of-the-
art report. Chem Eng Process: Process Intensif. 2013;64:79–97.
[17] Mozaffari Naeini R. Investigation on the standard flow pattern
using nano-micro air -bubbles, Master Thesis. Semnan, Iran:
Shahrood University of Technology; 2014 in Farsi.
[18] Meegoda JN, Aluthgun Hewage S, Batagoda JH. Stability of
nanobubbles. Environ Eng Sci. 2018;35(11):1216–27.
[19] Barnaby SW. On the formation of cavities in water by screw
propellers at high speeds. J Am Soc Nav Eng. 1897;9(4):678–83.
[20] Xiong Y, Peng F. Optimization of cavitation venturi tube design for
pico and nano bubbles generation. Int J Min Sci Technol.
2015;25(4):523–9.
[21] Hewage SA, Kewalramani J, Meegoda JN. Stability of nanobubbles
in different salt solutions. Colloids Surf A: Physicochem Eng Asp.
2021;609:125669.
[22] Chen C, Li J, Zhang X. The existence and stability of bulk nano-
bubbles: a long-standing dispute on the experimentally observed
mesoscopic inhomogeneities in aqueous solutions. Commun
Theor Phys. 2020;72(3):037601.
[23] Yildirim T, Yaparatne S, Graf J, Garcia-Segura S, Apul O.
Electrostatic forces and higher order curvature terms of
Young–Laplace equation on nanobubble stability in water. NPJ
Clean Water. 2022;5(1):18.
[24] Ushikubo FY, Enari M, Furukawa T, Nakagawa R, Makino Y,
Kanagoe Y, et al. Zeta potential of micro-and/or nano-bubbles in
water produced by some kinds of gases. IFAC Proceedings
Volumes. Vol. 43, No. 26, 2010. p. 283–8.
[25] Sheikh Hassani M, Torki A, Asadollahfardi G, Saghravani SF,
Shafaei J. The effect of water-to-cement ratio and age on the
mechanical properties of cement mortar and concrete made of
micro‐nano bubbles without adding any admixtures. Struct
Concr. 2021;22:E756–68.
[26] Clift R, Grace JR, Weber ME. Bubbles, drops, and particles. New
York: Dover Publications; 2005.
[27] Stokes GG. On the effect of the internal friction of fluids on the
motion of pendulums. Transactions of the Cambridge
Philosophical Society; 1851.
[28] Hu L, Xia Z. Application of ozone micro-nano-bubbles to
groundwater remediation. J Hazard Mater. 2018;342:446–53.
[29] Lu GW, Gao P. Emulsions and microemulsions for topical and
transdermal drug delivery. Handbook of non-invasive drug
delivery systems. UK: Elsevier; 2010. p. 59–94.
[30] Zhang XY, Wang QS, Wu ZX, Tao DP. An experimental study on
size distribution and zeta potential of bulk cavitation nanobub-
bles. Int J Miner Metall Mater. 2020;27:152–61.
[31] Liu S, Wang Q, Sun T, Wu C, Shi Y. The effect of different types of
micro‐bubbles on the performance of the coagulation flotation
process for coke waste water. J Chem Technol Biotechnol.
2012;87(2):206–15.
[32] Takahashi M, Chiba K, Li P. Free-radical generation from collap-
sing microbubbles in the absence of a dynamic stimulus. J Phys
Chem B. 2007;111(6):1343–7.
[33] Achar JC, Nam G, Jung J, Klammler H, Mohamed MM. Microbubble
ozonation of the antioxidant butylated hydroxytoluene:
Degradation kinetics and toxicity reduction. Environ Res.
2020;186:109496.
20 Abolfazl Soleymani Tushmanlo et al.

[34] Kwon H, Mohamed MM, Annable MD, Kim H. Remediation of
NAPL-contaminated porous media using micro-nano ozone
bubbles: Bench-scale experiments. J Contam Hydrol.
2020;228:103563.
[35] Koehler EP, Fowler DW. Development of a portable rheometer for
fresh portland cement concrete. Austin: The University of
Texas; 2004.
[36] Yahia A, Khayat KH. Analytical models for estimating yield stress
of high-performance pseudoplastic grout. Cem Concr Res.
2001;31(5):731–8. doi: 10.1016/S0008-8846(01)00476–8.
[37] Shen Y, Longo ML, Powell RL. Stability and rheological behavior of
concentrated monodisperse food emulsifier coated microbubble
suspensions. J Colloid Interface Sci. 2008;327(1):204–10.
[38] Trevor English. From dirty to clean: How a water treatment plant
work. https://interestingengineering.com/innovation/dirty-clean-
how-water-treatment-plant-works. (accessed Mar. 20, 2024)
Available from: .
[39] Jack DiGangi. Innovation Earth Solution.”nd”. https://www.
innearthsolutions.com/groundwater-remediation/. Avalible from
(accessed Mar. 20, 2024).
[40] Beatrice McGraw. What Makes Food Sector a Complex Industry.
https://blog.exporthub.com/what-makes-food-sector-a-complex-
industry/ Available from (accessed Mar. 20, 2024).
[41] Changying Z. Carbon Neutrality. https://link.springer.com/
journal/43979. Available from (accessed Mar. 20, 2024).
[42] JeffE. Cellular and Molecular Biology. https://www.nature.com/
collections/beddibeidd. Available from (accessed Mar. 20, 2024).
[43] Tina O. How to Claim a Tax Deduction for Medical Expenses in
2024. https://www.nerdwallet.com/article/taxes/medical-
expense-tax-deduction.(accessed Mar. 20, 2024).
[44] Diane BM. Managing the Water Under Our Feet: Groundwater.
“nd”; accessed Mar. 20 2024. https://my.lwv.org/california/
torrance-area/article/managing-water-under-our-feet-
groundwater.
[45] Serban E. Fishing industry, aquaculture fishery infographic. “nd”.
https://www.dreamstime.com/fishing-industry-aquaculture-
fishery-infographic-commercial-fish-catch-diagrams-vector-
production-statistics-lake-image143705113 (accessed Mar.
20, 2024).
[46] Minamikawa K, Takahashi M, Makino T, Tago K, Hayatsu M.
Irrigation with oxygen-nanobubble water can reduce methane
emission and arsenic dissolution in a flooded rice paddy. Environ
Res Lett. 2015;10(8):084012.
[47] Ebina K, Shi K, Hirao M, Hashimoto J, Kawato Y, Kaneshiro S, et al.
Oxygen and air nanobubble water solution promote the growth
of plants, fishes, and mice. PLoS One. 2013;8(6):e65339.
[48] Inatsu Y, Kitagawa T, Nakamura N, Kawsaki S, Nei D, Bari L, et al.
Effectiveness of stable ozone microbubble water on reducing
bacteria on the surface of selected leafy vegetables. Food Sci
Technol Res. 2011;17(6):479–85.
[49] Ikeura H, Kobayashi F, Tamaki M. Removal of residual pesticide,
fenitrothion, in vegetables by using ozone microbubbles gener-
ated by different methods. J Food Eng. 2011;103(3):345–9.
[50] Serizawa A. Fundamentals and applications of micro/nanobub-
bles. Paper presented at International Symposium on Application
of High Voltage, Plasmas, and Micro/Nano Bubbles to Agriculture
and Aquaculture; 2017.
[51] Yang Y, Chen Q. The application of ozone micro-nano bubble
treatment vegetable fresh-keeping technology in air logistics
transportation. Adv Mater Sci Eng. 2022;2022.
[52] Zhang Z-H, Wang S, Cheng L, et al. Micro-nano-bubble technology
and its applications in the food industry: A critical review. Food
Rev Int. 2022;39:1–23.
[53] Liu S, Oshita S, Makino Y, Wang Q, Kawagoe Y, Uchida T. Oxidative
capacity of nanobubbles and its effect on seed germination. ACS
Sustain Chem & Eng. 2016;4(3):1347–53.
[54] Liu Y. Application of micro-nano bubbles on bioconversion of
carbon dioxide and hydrogen to methane. Doctoral dissertation.
Graduate School of Life and Environmental Sciences; 2018.
[55] Liu J-J, Zhang T-Z, Li X-L, Zhao Y-L. Influence of nano water on the
germination, growth, and output of lettuce. North Hortic. 2018;6:6.
[56] Cho B, Kato K, Takahashi M. Nivolumab versus chemotherapy in
advanced esophageal squamous cell carcinoma (ESCC): the phase
III ATTRACTION-3 study. Ann Oncol. 2019;30:v873–4.
[57] Marui T. An introduction to micro/nano-bubbles and their appli-
cations. Syst Cybern Inform. 2013;11(4):68–73.
[58] Zhao X, Ranaweera R, Luo L. Highly efficient hydrogen evolution
of platinum via tuning the interfacial dissolved-gas concentration.
Chem Commun. 2019;55(10):1378–81.
[59] Yekeen N, Manan MA, Idris AK, Padmanabhan E, Junin R,
Samin AM, et al. A comprehensive review of experimental studies
of nanoparticles-stabilized foam for enhanced oil recovery. J Pet
Sci Eng. 2018;164:43–74.
[60] Yin T, Wang P, Zheng R, Zheng B, Cheng D, Zhang X, et al.
Nanobubbles for enhanced ultrasound imaging of tumors. Int J
Nanomed. 2012;7:895–904.
[61] Orel V, Zabolotny M, Orel V. Heterogeneity of hypoxia in solid
tumors and mechanochemical reactions with oxygen nanobub-
bles. Med Hypotheses. 2017;102:82–6.
[62] Gulafsha M, Anuroopa P. Miracle of ozone in dentistry: an over-
view. World J Pharm Res. 2019;8(3):665–77.
[63] Hayakumo S, Arakawa S, Takahashi M, Kondo K, Mano Y, Izumi Y.
Effects of ozone nano-bubble water on periodontopathic bacteria
and oral cells-in vitro studies. Sci Technol Adv Mater. 2014;15:1–7.
[64] Thakur SS, Chen Y-S, Houston ZH, Fletcher N, Barnett NL,
Thurecht KJ, et al. Ultrasound-responsive nanobubbles for
enhanced intravitreal drug migration: An ex vivo evaluation. Eur J
Pharm Biopharm. 2019;136:102–7.
[65] Kreft H, Jetz W. Global patterns and determinants of vascular
plant diversity. Proc Natl Acad Sci. 2007;104(14):5925–30.
[66] Tansel B, Pascual B. Removal of emulsified fuel oils from brackish
and pond water by dissolved air flotation with and without
polyelectrolyte use: Pilot-scale investigation for estuarine and
near shore applications. Chemosphere. 2011;85(7):1182–6.
[67] Polman A. Solar steam nanobubbles. ACS Nano. 2013;7(1):15–8.
[68] Koichi T, Shun A, Daisuke K. Removal of iron oxide fine particles
from wastewater using microbubble floatation. Prog Multiph
Flow Res. 2008;3:43–50.
[69] Meegoda J. Remediation of contaminated sediments with ultrasound
and ozone nano-bubbles. Award Abstract # 1634857. 2016;30:2020.
[70] Bauer W. Nanobubble-containing liquid solutions, US Pat.,
20160236158A1.
[71] Chu L-B, Yan S-T, Xing X-H, Yu A-F, Sun X-L, Jurcik B. Enhanced sludge
solubilization by microbubble ozonation. Chemosphere. 2008;72(2):205–12.
[72] Akiko F, Makoto T, Yoichiro M. Water treatment technique based
on microbubbles/nanobubbles. Physics of microbubbles and
their applications. Environ Solut Technol. 2005;4:17–20.
[73] Ahmadi R, Khodadadi DA, Abdollahy M, Fan M. Nano-microbubble
flotation of fine and ultrafine chalcopyrite particles. Int J Min Sci
Technol. 2014;24(4):559–66.
Using micro-nanobubble water in concrete 21

[74] Jin N, Zhang F, Cui Y, Sun L, Gao H, Pu Z, et al. Environment-
friendly surface cleaning using micro-nano bubbles. Particuology.
2022;66:1–9.
[75] Gohari N, Dehrazma B, Mirzaii M, Sagharvani SF, Fazli M. “Effect
of ozone micronano bubbles on the removal of infectious
pathogens in contaminated water: escherichia coli, pseudomonas
aeruginosa, staphylococcus aureus, and enterococcus faecalis.
J Environ Eng. 2024;150(3):04024001.
[76] Zhang X, Zhang H, Gao H, He Y, Jiang M. Effect of bubble feature
parameters on rheological properties of fresh concrete. Constr
Build Mater. 2019;196:245–55.
[77] Grzegorczyk-Frańczak M, Barnat-Hunek D, Materak K, Łagód G.
Influence of water with oxygen and ozone micro-nano bubbles on
concrete physical properties. Materials. 2022;15(22):7938.
[78] ArefiA, Saghravani SF, Mozaffari Naeeni R. Mechanical behavior
of concrete, made with micro-nano air bubbles. Civ Eng
Infrastruct J. 2016;49(1):139–47.
[79] Grzegorczyk-Frańczak M, Barnat-Hunek D, Andrzejuk W,
Zaburko J, Zalewska M, Łagód G. Physical properties and dur-
ability of lime-cement mortars prepared with water containing
micro-nano bubbles of various gases. Materials. 2021;14(8):1902.
[80] Asadollahfardi G, MohsenZadeh P, Saghravani SF. The effects of
using metakaolin and micro-nanobubble water on concrete
properties. J Build Eng. 2019;25:100781.
[81] Mohsen Zadeh P, Saghravani SF, Asadollahfardi G. Mechanical
and durability properties of concrete containing zeolite mixed
with meta‐kaolin and micro‐nano bubbles of water. Struct Concr.
2019;20(2):786–97.
[82] Kim W-K, Kim Y-H, Hong G, Kim J-M, Han J-G, Lee J-Y. Effect of
hydrogen nanobubbles on the mechanical strength and water-
tightness of cement mixtures. Materials. 2021;14(8):1823.
[83] Wan Z, He T. Micro-nano bubble water process: effect of micro-
nano bubble water as mixing water on volume stability of shot-
crete. Mater Today Commun. 2023;106469.
[84] Lan X-L, Zhu H-S, Zeng X-H, Long G-C, Xie Y-J. How do nano-bubble
water and nano-silica affect the air-void characteristics and
freeze-thaw resistance of air-entrained cementitious materials at
low atmospheric pressure? J Build Eng. 2023;69:106179.
[85] Kim W-K, Hong G, Kim Y-H, et al. Mechanical strength and
hydration characteristics of cement mixture with highly concen-
trated hydrogen nanobubble water. Materials. 2021;14(11):2735.
[86] Khoshroo M, Javid AAS, Katebi A. Effects of micro-nano bubble water
and binary mineral admixtures on the mechanical and durability
properties of concrete. Constr Build Mater. 2018;164:371–85.
[87] Tayebi Jebeli M, Asadollahfardi G, Abbasi Khalil A. Novel application of
micro-nanobubble water for recycling waste foundry sand: toward
green concrete. J Constr Eng Manag. 2022;148(9):04022096.
[88] Lee N, Kang S-H, Moon J. Experimental study on the improvement
of workability of cementitious composites using nano-bubble
water. J Korea Inst Struct Maint Inspection. 2021;25(6):27–32.
[89] He S, He T, Wan Z, Qing Z. Effect of micro-nano bubble water and
silica fume on properties of C60 concrete. Materials.
2023;16(13):4684–4.
[90] Wan Z, He T, Chang N, He S, Shao Z, Ma X, et al. Study on frost
resistance of shotcrete by micro-nano bubble water and admix-
ture. Ceram Int. 2023;49(7):11123–39.
[91] Chang J, Zhang H, Liu F, Cui K. Exploring the mechanism of micro-
nano bubble water in enhancing the mechanical properties of
sulfoaluminate cement-based materials. Constr Build Mater.
2024;411:134400.
[92] Chen Y, Han J-G, Lee J, Shinebayar S. Advantages of Hydrogen
Nanobubble-rich Concrete in Workability and Mechanical prop-
erties. Case Stud Constr Mater. 2024;20:e03164.
[93] Tochahi PM, Asadollahfardi G, Saghravani SF,
Mohammadzadeh N. Curing of concrete specimens containing
metakaolin, zeolite, and micro nanobubbles water in seawater.
Mater J. 2024.
[94] EFNARC. The european guidelines for self-compacting concrete.
Eur Guidel Self Compact Concr. 2005;63.
[95] British Standards Institution. BS 8500, concrete –Complementary
British Standard to BS EN 206-1-BS1; 2019.
[96] Kanyenze SS, Joubert DJ, Combrinck R. The effect of nanobubble
water on the fresh properties of conventional concrete and 3d
printing concrete. Conference: Young Concrete Researchers,
Engineers & Technologists (YCRETS); 2023. p. 88–95 Symposium.
[97] Asadollahfardi G, Katebi A, Taherian P, Panahandeh A.
Environmental life cycle assessment of concrete with different
mixed designs. Int J Constr Manag. 2021;21(7):665–76.
[98] Taherian P. Economic and environmental life cycle assessment of
concrete samples with different designs and various combinations.
Master’s Thesis. Karaj, Iran: Kharazmi University; 2018 in Farsi.
[99] Alsaffar KA. Review of the use of nanotechnology in the con-
struction industry. Int J Eng Res Dev. 2014;10(8):67–70.
[100] Khan P, Zhu W, Huang F, Gao W, Khan NA. Micro–nanobubble
technology and water-related application. Water Supply.
2020;20(6):2021–35.
[101] Jia M, Farid MU, Kharraz JA, Kumar NM, Chopra SS, Jang A, et al.
Nanobubbles in water and wastewater treatment systems: small
bubbles making a big difference. Water Res. 2023;245:120613.
doi: 10.1016/j.watres.2023.120613
[102] Abdelgader HS, Marzena K, Mugahed A. Effect of slag coal ash
and foamed glass on the mechanical properties of two-stage
concrete. Mater Today: Proc. 2022;58:1091–7.
[103] Moaf OF, Kazemi F, Abdelgader HS, Marzena K. Machine learning-
based prediction of preplaced aggregate concrete characteristics.
Eng Appl Artif Intell. 2023;123:106387.
[104] Rajabi AM, Omidi Moaf F, Abdelgader HS. Evaluation of
mechanical properties of two-stage concrete and conventional
concrete using nondestructive tests. J Mater Civ Eng.
2020;32(7):04020185.
22 Abolfazl Soleymani Tushmanlo et al.