Nino Grizzuti

• University of Naples Federico II

Heat-induced gelation of egg proteins, influenced by factors such as temperature and time, affects texture. This study compares three cooking methods—hard-boiling, sous vide, and periodic cooking—using rheological measurements to investigate the sol–gel transition and texture development in both egg phases. The goal is to understand how thermal his...

Pluronic block copolymers are thermosensitive amphiphilic materials capable of self-assembling with various phases in water environments, depending on temperature and concentration. The phase transitions of high-concentrated Pluronic solutions in water (H2O) and heavy water (D2O) were observed via experimental rheology and small-angle x-ray scatter...

Pluronics, alias poloxamers, are synthetic amphiphilic copolymers owning a triblock structure with a central hydrophobic poly(propylene oxide) (PPO) segment linked to two lateral hydrophilic poly(ethylene oxide) (PEO) chains. Commercially, Pluronics exist in numerous types according to the length of PPO and PEO chains, exhibiting different behavior...

Emulsions play a pivotal role in many industrial fields, including food, pharmaceutics, and cosmetics. This paper explores the simultaneous effects of varying concentrations of Pluronic and Sodium Alginate (Alg), with particular attention to the resulting stability and the rheological properties of the incoming oil-in-water emulsions. Pluronics are...

Aqueous solutions of Konjac glucomannan (KGM)/κ‐Carrageenan (κ‐C) of different ratios (1:2, 1:5, 1:8 and 1:10) and a fixed κ‐C content of 1.5%, were proposed as a new 3D food printing ink. Their thermo‐responsive behaviour was evaluated by temperature ramp rheological tests. This characterisation allowed for the evaluation of the synergistic effect...

The evaluation of drug percutaneous absorption plays a pivotal role in assessing the efficacy of dermal/transdermal drug delivery systems. Drug therapies rely on biomedical systems capable of precisely regulating drug dosage, controlling the rate of drug release, and mitigating the common side effects associated with many drug delivery formulations...

Age-long ambition of medical scientists has always been advancement in healthcare and therapeutic medicine. Biomedical research indeed claims paramount importance in nanomedicine and drug delivery, and the development of biocompatible storage structures for delivering drugs stands at the heart of emerging scientific works. The delivery of drugs int...

In recent years, advancements in bioengineering and materials science have witnessed increasing interest in synthetic polymers capable of fulfilling various applications. Owing to their distinctive properties, Pluronics can be used as nano-drug carriers, to deliver poorly water-soluble drugs, and as model systems to study colloidal science by tunin...

Exploring opportunities for biowaste valorization, herein, humic substances (HS) were combined with gelatin, a hydrophilic biocompatible and bioavailable polymer, to obtain 3D hydrogels. Hybrid gels (Gel HS) were prepared at different HS contents, exploiting physical or chemical cross-linking, through 1-ethyl-(3-3-dimethylaminopropyl)carbodiimide (...

Polyethylene terephthalate (PET) is a thermoplastic material that is widely used in many application fields, such as packaging, construction and household products. Due to the relevant contribution of PET to global yearly solid waste, the recycling of such material has become an important issue. Disposed PET does not maintain the mechanical propert...

Hydrocolloids are long-chain biopolymers that can form viscous solutions or gels when dissolved in water. They are employed as rheological modifiers in various manufacturing processes or finished products. Due to its unique gelation properties, animal gelatin is one of the most widely used hydrocolloids, finding applications in several fields such...

We report on shear startup data for two wormlike micellar solutions, differing only in concentration and type of two binding aromatic sodium salts. The surfactant molecule is cetylpiridinium chloride at a fixed concentration (100 mM). Sodium salicylate (NaSal) and diclofenac sodium (Diclo) are used as binding salts at concentrations 68 mM NaSal and...

We analyzed bubble rupture and hole opening dynamics in a non-Newtonian fluid by investigating the retraction process of thin films after inflation at different blowing rates. The experiments were modeled through a dimensional analysis, with the aim of establishing a general approach on the bubble rupture dynamics and discerning the role of viscous...

We investigate the linear and nonlinear shear flow properties of several polystyrene solutions in the unentangled state. The solutions are made up of long (linear) polystyrene chains dissolved in oligostyrene at sufficiently small volume fractions such that the critical entanglement molar mass remains larger than that of the polymer. The use of a c...

We investigate the linear rheology of ultrahigh molecular weight polyethylene (UHMWPE) solutions with the aim of determining the molecular weight distribution of the polymer. The UHMWPE is dissolved in oligo-ethylene in order to avoid issues related to unfavorable interactions with the solvent. To prepare the solutions, UHMWPE, solvent, and a fixed...

Additive manufacturing—in particular, three-dimensional (3D) printing—has been introduced since the late 1980s, offering a novel paradigm for engineering design and manufacturing, as it allows the fabrication of very complex structures. Additive manufacturing of hydrogels is a very popular method to produce scaffolds to be used in tissue engineerin...

We investigate the rheological behavior of aqueous solutions containing animal gelatin, sugars and polyols. The aim is to study how the gelation kinetics, transition temperatures and gel strengths of an aqueous gelatin solution can be affected by the progressive addition of co-solutes. Aqueous solutions with a fixed mass percentage of gelatin of 6....

This paper investigates the production of a yeast-free pizza by gas foaming and the use of rheology to guide the process design. The novel process relies on the use of a gaseous blowing agent and a pressure program to form and stabilize bubbles during baking, avoiding the use of yeast and the associated lengthy leavening stage. The evolution of the...

Exploring the chance to convert biowaste into a valuable resource, this study tests the potential role of humic acids (HA), a class of multifunctional compounds obtained by oxidative decomposition of biomass, as physical agents to improve gelatin’s mechanical and thermal properties. To this purpose, gelatin–HA aqueous samples were prepared at incre...

3D numerical simulations were used to study the flow behavior of Newtonian and yield power-law fluids in two rotational geometries equipping a laboratory benchmark rheometer, namely, a standard concentric cylinder geometry and a non-viscometric, mixing-oriented double helical ribbon tool. Simulations are performed employing the COMSOL Multiphysics...

Gelatin gels are known to be nonequilibrium systems, because of the continuous growth and rearrangements of physical junctions, even in the solidlike state. Establishing a relationship between the relative degree of cross-linking and macroscopic elasticity would be crucial in understanding, modeling, and predicting the transformation processes of g...

We report the design of a microcapillary rheometer (μCR) that allows to perform experiments rapidly and in a broad range of shear rates (i.e., from 0.1 to 1000 s⁻¹), using small amounts of material (i.e., just few milligrams). Additionally, multiple measurement parallelization makes it suitable for High-Throughput Rheological Experimentation of pol...

Thermoplastic polymer–filler composites are excellent materials for bone tissue engineering (TE) scaffolds, combining the functionality of fillers with suitable load-bearing ability, biodegradability, and additive manufacturing (AM) compatibility of the polymer. Two key determinants of their utility are their rheological behavior in the molten stat...

We investigated the morphological transitions of aqueous solutions of Pluronic F68 induced by temperature and polymer concentration by means of rheological and x-ray measurements. We adopted a rheological method to evaluate the characteristic equilibrium temperatures associated with the transition from unimers to spherical micelles and from disorde...

Thermoplastic polymer - filler composites are excellent materials for bone tissue engineering (TE) scaffolds, combining the functionality of fillers with suitable load bearing ability, biodegradability, and additive manufacturing (AM) compatibility of the polymer. Two key determinants of their utility are their rheological behavior in the molten st...

We investigate the sol-gel transition of aqueous pig-skin gelatin solutions at different concentrations and temperatures. In particular, we characterize the isothermal gelation kinetics close to the critical melting temperature, previously evaluated with dynamic temperature ramp tests. The time evolution of the moduli is analyzed at a specific fixe...

We report shear startup data on solutions of entangled linear wormlike micelles, only differing in the concentration of a binding aromatic salt. Wormlike micelles behave similarly to ordinary polymers in fast shear flows, exhibiting pronounced overshoots as well as tiny undershoots in transient shear viscosity, before approaching the steady state....

The rheology of macroscopic particle suspensions is relevant in many industrial applications, such as cement-based suspensions, synthetic and natural drilling fluids. Rheological measurements for these complex, heterogeneous systems are complicated by a double effect of particle size. On the one hand, the smallest characteristic length of the measu...

The crystalline morphology of ethylene/1-octene (EO-BC) statistical multiblock copolymers is investigated by transmission electron microscopy (TEM). EO-BCs are an important class of thermoplastic elastomers characterized by alternating crystalline, octene-poor, hard blocks and amorphous, octene-rich, soft blocks and statistical distribution of bloc...

The tacticity of vinyl polymer chains strongly affects the physical properties of polymeric materials , as example the chain conformations and stiffness. In the present work we tested how the hybrid Particle-Field Molecular Dynamics (PF-MD) technique is capable to describe conformational differences of polymer chains as function of the tacticity. I...

Concentrated aqueous solutions of surfactants, often referred to as pastes, experience complex phase and rheology changes upon dissolution in water, which is a typical step in the production of liquid detergents. During the dilution process, depending on water content, surfactant molecules can arrange in different morphologies, such as lamellar or...

We report an experimental study on suspensions of solid particles in a viscoelastic polymer matrix. A commercial entangled poly(ε-caprolactone) was used as the suspending fluid. Noncolloidal solid spheres (diameter = 15 μm) made of polymethylmethacrylate were dispersed in the polymer via a solvent casting method. The volume fraction of the spheres...

One good way to explore fluid microstructure, experimentally, is to suddenly subject the fluid to a large steady shearing deformation and to then observe the evolving stress response. If the steady shear rate is high enough, the shear stress and also the normal stress differences can overshoot, and then they can even undershoot. We call such respon...

During laboratory practice, it is often necessary to perform rheological measurements with small specimens, mainly due to the limited availability of the investigated systems. Such a restriction occurs, for example, because the laboratory synthesis of new materials is performed on small scales, or can concern biological samples that are notoriously...

Aqueous solutions of tri-block co-polymer surfactants are able to aggregate into a rich variety of microstructures, which can exhibit different rheological behaviors. In this work, we study the diversity of structures detected in aqueous solutions of Pluronic L64 at various concentrations and temperatures by experimental rheometry and dissipative p...

We investigate the rheological properties of a simplified version of a liquid detergent composed of an aqueous solution of the linear alkylbenzene sulphonate (LAS) surfactant, in which a small amount of fibers made of hydrogenated castor oil (HCO) is dispersed. At the concentration typically used in detergents, LAS is in a worm-like micellar phase...

The crystallization behavior of five Syndiotactic Polypropylene (sPP) samples of varying degree of tacticity has been studied by means of rheological techniques and compared to the results of more standard DSC measurements. Small Amplitude Oscillatory Shear (SAOS) measurements have been performed on a controlled stress rotational rheometer equipped...

When a Newtonian bubble ruptures, the film retraction dynamics is controlled by the interplay of surface, inertial and viscous forces. In case a viscoelastic liquid is considered, the scenario is enriched by the appearance of a new significant contribution, namely, the elastic force. In this paper, we investigate experimentally the retraction of vi...

We report on the inverse thermogelation of aqueous solutions of high molecular weight HydroxyPropylCellulose (HPC). The gelation process is investigated at different polymer concentrations, in the range 4÷16% (w/w). For each concentration, different heating rates are considered, in order to explore the effects on the sol-gel transition. Our finding...

The rising of spherical bodies in structured fluids with yield stress is studied. The system is a suspension of hydrogenated castor oil colloidal fibers in a surfactant micellar solution. The fiber network confers to the fluid a viscoelastic behavior, with a well-defined yield stress, which increases with increasing fiber concentration.Various flui...

Surfactant molecules can give rise to different morphological structures, depending on numerous parameters such as temperature, surfactant concentration and salinity. Specifically, the salt content can be easily tuned in a way to induce morphological transitions and modulate the rheological response. It is shown that non steroidal anti-inflammatory...

DOI:https://doi.org/10.1103/PhysRevE.95.049902

The shear flow dynamics of linear and branched wormlike micellar systems based on cetylpyridinium chloride and sodium salicylate in brine solution is investigated through rheometric and scattering techniques. In particular, the flow and the structural flow response are explored via velocimetry measurements and rheological and rheometric small-angle...

The micellar system based on cetylpyridinium chloride (CPyCl) and sodium salicylate (NaSal) in brine solution is investigated on both macro- and micro-length scales through rheology and scattering measurements. The linear viscoelasticity of the system and its structural parameters are explored by systematically changing the amount of NaSal over an...

In this work a design tool to control cell-opening in gas foaming of thermoplastic polymers is developed. The sequence of events following bubble nucleation, namely, bubble growth and impingement, are modeled to gain a comprehensive, perspective view on the mechanisms of bubble wall rupture and on the conditions for achieving a fully open-cell morp...

Drug release from inorganic supports is a challenge for the scientific community for various reasons, related to the low costs of the systems and the possibility of easily regulating the drug release. In the present work, surface-modified zeolite particles are used as carriers for non steroidal antiflammatory drugs (NSAIDs). The release of the drug...

The micellar system composed by Cetylpyridinium Chloride-Sodium Salicylate (CPyCl-NaSal) in brine aqueous solutions has been studied by systematically changing the salt concentration, in order to investigate the rheology of the arising morphologies. In particular, the zero-shear viscosity and the linear viscoelastic response have been measured as a...

Copper(II) complexes containing chiral centres and functionalised with citronellyl end groups were synthesised. Isomerisation of citronellyl double bond was exploited to decrease the melting temperature of the complexes and improve their solubility in organic media. The chiral metallomesogens were successfully used to produce induced cholesteric so...

Rheometry is the body of techniques that are used to measure the material functions of complex materials. It provides the experimental ‘armed wing’ for rheology that studies the deformation and flow of matter. In this document, the main, state-of-the-art rheometric techniques are reviewed and discussed. After introducing the basic definitions and t...

Poly(3-hydroxybutyrate) (PHB) is a biodegradable polymer, whose applicability is limited by its relatively poor mechanical properties and narrow processing window. In this paper, a natural polyphenolic additive, tannic acid (TA) was used as thermal and processing stabilizer for PHB. The thermal stability of both neat and TA-doped PHB samples was st...

Migration and chaining of noncolloidal spheres in a worm-like micellar, viscoelastic solution under shear flow have been studied both experimentally and by numerical simulations. The microstructure dynamics have been experimentally investigated in the flow-gradient and in the flow-vorticity planes. 2D simulations in the flow-gradient plane have bee...

A set of syndiotactic polypropylene samples with tailored degree of stereoregularity and uniform distribution of stereodefects, obtained via organometallic catalysis, was used to study the relation between the syndiotactic pentad concentration and the viscoelastic plateau modulus in the melt state. The plateau modulus was found to increase with inc...

A detailed rheological study of aqueous solutions of methylhydroxyethylcellulose has been carried out in the presence of different acrylate-based graft polymer used as additive contents. Both polymer components are used in cement formulations to improve the flow performances of the concretes, but no physicochemical studies can be easily found in th...

Flow-Induced Self-Assembly (FISA) is the flow-driven formation of ordered structures in complex fluids. In this paper the effect of shear flow on the microstructure formation of dilute sphere suspensions in a viscoelastic fluid has been studied experimentally by optical microscopy techniques. The system is formed by Polymethylmethacrylate beads sus...

The consequences of the interfacial mobility on the coalescence process in immiscible polymer blends was studied. Blends of PIB and PDMS with 10 vol.% PIB were subjected to shear-flow step-down experiments under controlled conditions. The blend was initially sheared at high shear rate to obtain a fine dispersion (small drop size). The shear rate wa...

Flow-induced structures in suspensions containing spheres in viscoelastic suspending media were investigated by microscopy and rheo-optical methods. Suspensions of monodisperse polystyrene spheres with diameters ranging from 1.2 to 2.8μm and dispersed in aqueous solutions of hydroxypropylcellulose were studied in simple shear flows. Optical microsc...

Ordering induced by shear flow can be used to direct the assembly of particles in suspensions. Flow-induced ordering is determined by the balance between a range of forces, such as direct interparticle, Brownian, and hydrodynamic forces. The latter are modified when dealing with viscoelastic rather than Newtonian matrices. In particular, 1D stringl...

In this article, we show that the crystallization behaviour of a rubber-filled polypropylene, under isothermal conditions, can be monitored by means of parallel plate rheometry and differential scanning calorimetry. Data collected with different instruments can be compared only after performance of accurate temperature calibration. The complex modu...

The dissipative behavior of model suspensions composed of non-Brownian, inertialess, rigid spheres immersed in Newtonian and viscoelastic matrices is investigated in the range of volumetric concentrations up to 10%, thus encompassing both the dilute and semidilute regimes. Polymethylmethacrylate beads are dispersed into polyisobutylene, characteriz...

The rheology of non-Brownian, inertialess rigid spheres suspended in viscoelastic fluids was investigated in the dilute and semi-dilute regimes (volume fractions up to 10%), where interparticle interactions become increasingly relevant. PMMA spherical particles were suspended in viscoelastic Polydimethylsiloxanes (PDMS). A Newtonian fluid (Polyisob...

In this work we analyze the crystallization kinetics under steady shear flow conditions of different samples obtained by blending two isotactic poly(1-butene)s with different average molecular weights. It is observed that the addition of a small amount of high MW-polymer (< 10 wt%) to a low MW-sample does not produce any appreciable effect upon the...

In this paper we analyze the crystallization kinetics under steady shear flow conditions of different samples obtained by blending two isotactic poly(1-butene)s with different average molecular weights. It is observed that the addition of a small amount of high molecular weight (MW) polymer (<6 wt %) to a low MW sample does not produce any apprecia...

We investigated the linear melt viscoelasticity and the crystallization kinetics of a series of model poly(ethylene oxide) stars with different functionalities (f=4-32 arms) and moderately entangled arms (their molecular masses ranging from 5.5 to 12 kgmol). The limited data in the homogeneous state indicated that the zero-shear viscosity 0 was ade...

In this paper, the rheological properties of an extrudable cement-based paste are investigated by means of an original ram extrusion apparatus (capillary rheometer). The experimental results indicate that a careful measurement of the die pressure is necessary to obtain a realistic viscosity vs shear rate curve, as required in extrusion technology....

The thermal and chemical stability of enzymes is usually analyzed by measuring variations in initial rates of the enzymatic reaction, or in some protein structure-related physicochemical property, as a function of operating conditions (temperature, pH, denaturant, concentration, etc.). Little, if any, attention is devoted to the long-term behavior,...

The thermoreversible gelation of hydroxypropylcellulose (HPC)/water solutions is investigated by means of rheological and optical techniques. The linear viscoelasticity of solutions at different concentrations is measured during heating ramps from room temperature. The experimental results suggest that the solution microstructure changes according...

In this paper, the quiescent crystallization of polycaprolactone (PCL) melts is studied by rheological measurements coupled to calorimetry and optical microscopy. Based on a comparison between the different techniques, we find that the increase in viscoelastic properties during crystallization starts only when a relatively high degree of crystallin...

Using rheological techniques, we investigate the evolution of the microstructure evolution during the early stages of quiescent crystallization of poly(1-butene). In performing the measurements, use is made of an innovative experimental protocol, called “inverse quenching”, which allows stopping the crystallization process and producing a stable bi...

The phase transition of a series of thermoplastic polyurethanes has been investigated by means of rheological and calorimetric techniques. Five different samples of varying molecular weight (MW) and hard-to-soft segment ratio have been studied. Thermal histories included isothermal annealing after cooling from the melt and heating cycles following...

The rich behavior of thermoplastic polyurethanes (TPUs) undergoing phase transition is investigated by means of combined rheological and DSC techniques. In particular, the kinetics of micro-phase transition of a commercial TPU are followed under both isothermal conditions (crystallization from the melt), and constant temperature rate heating ramps...

This study investigates the coupled effects of mild shear flow and temperature on the crystallization behavior of two thermoplastic polymers, namely, an isotactic polypropylene and an isotactic poly(1-butene). Rheological experiments are used to measure the crystallization induction time under isothermal, steady shear flow conditions. The experimen...

The phase transition behavior of a commercial thermoplastic polyurethane (TPU) is investigated by Theological techniques. Oscillatory shear flow experiments are performed during both the isothermal annealing following a rapid cooling from the melt state, and the subsequent heating ramp (remelting). Rheological measurements reveal that the microphas...

The interfacial tension of the uncompatibilized and compatibilized blends of low density polyethylene (LDPE) and polyamide 6 (PA6) has been measured by the breaking thread method. Different types of compatibilizer precursors have been used: poly(ethylene-co-acrylic acid) (Escor 5001, by Exxon) having 6 wt% concentration of acrylic acid; an ethylene...

In this work, we present two novel methods to determine the interfacial tension of a disperse polymer blend through rheo-optical measurements of flow-induced single drop distortions. A counter-rotating shearing device with transparent plates is used to measure drop distortions. The cell geometry allows for a top view of the deforming drop, i.e., al...

The flow-induced transition of liquid crystalline polymers (LCPs) is studied by rheological techniques. Aqueous solutions of hydroxypropylcellulose (HPC) in water are adopted as a model LCP system. Nonisothermal oscillatory tests are first used to quantitatively determine the “rheological” phase diagram of the HPC/water system under quiescent condi...

In this paper we show that a suitable thermal history can be used to produce a polymer melt in which a fixed amount of crystalline phase has been frozen. We call this novel method "inverse quenching," since a stable arnorphous/crystalline system is obtained by heating up the sample rather than cooling it down. If the inverse quenching temperature i...

The effects of recycling on the processability of two injection molding grade thermoplastic polymers has been investigated. Recycling of a Polypropylene (PP) and a Polyamide (Nylon 6, PA6) has been simulated by repeated injection molding cycles, followed by blending of the processed materials with the virgin polymer. The flow properties of both the...

Turbidity measurements were used to characterize the effect of shear flow on the crystallization kinetics of several isotactic poly(1-butene) samples of different molecular weight (MW). Polymer melts were rapidly cooled below the nominal crystallization temperature, and subjected to a shear flow of varying shear rate but constant total deformation....

Flow Induced Crystallization (FIC) is the common term to indicate the acceleration in polymer crystallization kinetics due to the action of flow. FIC is expected to be the result of the coupling between the intrinsic (quiescent) crystallization kinetics and the rheological response of the polymer. The choice of a suitable rheological model, therefo...

The effect of molecular weight on the crystallization behavior of isotactic poly(1-butene) (iPB) under quiescent, isothermal conditions is investigated by rheological and optical microscopy techniques. Small-amplitude oscillatory shear experiments are used to determine the critical gel behavior of the crystallizing melt. The resulting critical gel...

The problem of flow-induced crystallization (FIC) of polymer melts is addressed via a microrheological approach. In particular, the Doi−Edwards model with the so-called independent alignment approximation (DE−IAA) is used to calculate the flow-induced change of free energy. Subsequently, the crystallization induction time, i.e., the nucleation char...

A transparent flow cell apparatus has been used to obtain quantitative information on the morphology evolution of a model polymer blend flowing in complex flow fields. A dilute emulsion of poly-dimethylsiloxane droplets immersed in a poly-isobutene matrix, both Newtonian liquids at room temperature, has been chosen as a model system. Optical micros...

Flow Induced Crystallization (FIC) is the common term to indicate the acceleration in polymer crystallization kinetics due to the action of flow. When modeling FIC, two major challenges are encountered. On the one hand, the model must be able to produce quantitative reliable results, while correctly describing the coupling between the intrinsic (qu...

A laboratory spiral-disk extruder for the study of gas entrainment phenomena is presented. The rotating plate is transparent, thus allowing for the direct observation of the steady liquid-gas interface when operating under starve-fed conditions. The extruder flow is modeled with the conventional single screw extruder approach. This leads to a simpl...