Barry W Ninham

• Ph D
• Professor Emeritus at Australian National University

The glycocalyx and its associated endothelial surface layer which lines all cell membranes and most tissues, dwarfs the phospholipid membrane of cells in extent. Its major components are sulphated polymers like heparan and chondroitin sulphates and hyaluronic acid. These form a fuzzy layer of unknown structure and function. It has become increasin...

Specific ion effects are widespread and have been studied for over a century, yet they remain poorly understood. Terms like “kosmotropes” and “chaotropes” are convenient rules of thumb but the frequent reversal of the Hofmeister series implies their limitations. Polarizability is often used to classify ions, with kosmotropes considered low in polar...

Supplementary Information includes the full derivation of Casimir energy for N = 4 objects placed in top of the corners of Rhombus and 1D electron model.

We consider the dispersion (van der Waals, vdW) interaction among N parallel elongated objects such as DNA/RNA strands or metallic nanotubes, which are polarizable primarily along the long axis. Within a quasi-one-dimensional model, we prove that the irreducible N -object vdW energy contribution is negative (attractive) for even N and positive (rep...

We revive a 60-year-old idea that might explain a remarkable new observation of a periodic low-frequency radio emission from a source at galactic distances (GLEAM-X J162759.5-523504.3). It derives from the observation that a high-density high-temperature charged boson plasma is a superconducting superfluid with a Meissner effect.

The work reports a number of results on the dynamics of swelling and inferred nanostructure of the ion-exchange polymer membrane Nafion in different aqueous solutions. The techniques used were photoluminescent and Fourier transform IR (FTIR) spectroscopy. The centers of photoluminescence were identified as the sulfonic groups localized at the ends...

The precipitation of five amino acids: DL-alanine, L-arginine, L-leucine, DL-methionine and L-tyrosine was studied at their solubility limits and isoelectric point by using a bubble column evaporator (BCE). The precipitation of amino acids via a bubble column evaporator and a standard stirring method were compared via turbidity measurements. Partic...

It is shown how Maxwell’s equations for the electromagnetic field with Planck quantisation of allowed modes appears to provide a semiclassical account of nuclear interactions. The mesons emerge as plasmons, collective excitations in an electron positron pair sea. The lifetime and mass of mesons are predicted.

Unlike halides, where the kosmotropicity decreases from fluoride to iodide, the kosmotropic nature of halates apparently increases from chlorate to iodate, in spite of the lowering in the static ionic polarizability. In this paper, we present an experimental study that confirms the results of previous simulations. The lyotropic nature of aqueous so...

Many salts reduce the size of bubbles and inhibit bubble coalescence. The phenomenon occurs above the same concentration for some ion pairs (0.17 M for 1:1 salts). For other ion pairs no such effect occurs. The phenomenon remains inexplicable by standard theories of colloid science. It occurs for a range of sugar isomers and not for others. Again,...

The color of the pH indicator Bromothymol blue (BTB) changes from yellow to blue with increasing pH. The effect of some electrolytes (LiCl, NaCl, KCl, CsCl, KSCN and KClO3) and of D2O on the spectral properties of dilute solutions of BTB is explored. The results are interpreted in terms of dimerization of the dye molecules and of the different hydr...

Chapter 1: COVID-19 pathogenesis poses paradoxes difficult to explain with traditional physiology. For instance, since type II pneumocytes are considered the primary cellular target of SARS-CoV-2; as these produce pulmonary surfactant (PS), the possibility that insufficient PS plays a role in COVID-19 pathogenesis has been raised. However, the opp...

When a membrane of Nafion swells in water, polymer fibers “unwind” into the adjoining liquid. They extend to a maximum of about ~300 μm. We explore features of Nafion nanostructure in several electrolyte solutions that occur when the swelling is constrained to a cell of size less than a distance of 300 μm. The constraint forces the polymer fibers t...

Hypothesis In Part 1 of this work we reported the behavior of a moderately concentrated dispersion of sodium oleate (NaOL) in water that produces elongated wormlike micelles (WLMs). Prompted by the striking effect induced by adding potassium chloride to the original NaOL dispersion, here we investigate the effect of different anions (with fixed cat...

This study aims to explore the variety of previously unknown morphologies that brain lipids form in aqueous solutions. We study how these structures are dependent on cholesterol content, salt solution composition, and temperature. For this purpose, dispersions of porcine sphingomyelin with varying amounts of cholesterol as well as dispersions of po...

Alkylene carbonates such as ethylene, glycerol and propylene carbonates offer a valuable tool for the investigation of intermolecular interactions in polar non-aqueous liquids. Their physico-chemical properties suggest the presence of a strong structure that mainly depends on hydrogen bonds. The addition of salts bearing basic anions such as fluori...

This paper gives an updated review of the bubble column evaporator (BCE) and its various new processes. These include recent work on helium gas desalination and high temperature inlet gas decomposition. The BCE process offers a continuously produced source of high gas-water interface and consequently provides high overall heat and mass transfer coe...

In the oil industry, strontium sulfate (SrSO4) scale deposits have long plagued oilfield and gas production operations. This remains an unsolved problem. We here show how the bubble column evaporator (BCE) can be used to control aqueous precipitation from salt solutions. Mixtures of strontium nitrate and sodium sulfate in the BCE system were used...

Pollution of drinking water by toxic heavy-metal ions is a matter of concern worldwide. These ions occur naturally, and also from environmental spills, radioactive wastes and other industrial waste. Arsenic and lead are typical examples. A novel green surfactant, purpose designed, and environmentally friendly is shown to be extremely effective and...

A year ago, May 24, 2019 was the 500th anniversary of the death of Leonardo da Vinci. Visionary water projects on a grand scale were one of his lifelong passions. They were never fulfilled. Substantia offers this volume on new water technologies that work, in celebration of the life of da Vinci, the artist and genius of Florence. These technologies...

We have reported on a suite of simple new water technologies, in desalination, in sterilisation, in heavy metal pollution and harvesting, in cavitation, in a new class of environmentally friendly surfactants, on control of slimes and sludges from mining and floods. All are cheap, scalable. All are desperately needed. Why were these not developed be...

This paper reports the synthesis and properties of new polymer resins containing strong acid and base groups for optimising applications in desalination. Several polyampholytic gels were synthesised with a ratio of 1:1 of strong acid (sulphonate) and strong base (quaternary ammonium) groups and a zwitterionic resin with a 1:1 strong acid and base r...

A CO2 bubble column (CBC) has been developed as a body-temperature lab-scale water sterilization process for the inactivation of pathogens. Both CO2 and combustion gas bubbles inactivated Escherichia coli C-3000 (ATCC15597) with extraordinary efficiency in solutions with low alkalinity. The mechanisms of inactivation were not known. To characterise...

The recalcitrant nightmare of de-watering slime/sludge is a major issue, for both industry and the environment. A simple process is developed that solves the problem. It uses a bubble column evaporator (BCE) with heated dry air. The model slime to illustrate the de-watering process was a concentrated dispersion of spherical 5 micron silica particle...

Hypothesis The structure, rheology and other physicochemical properties of dilute aqueous dispersions of sodium oleate (NaOL) are well known. This paper is the first report in which a moderately concentrated (13% w/w) dispersion of NaOL in water is investigated. In fact, at this concentration the phase and rheology behavior of the surfactant remark...

When Nafion swells in water, colloidal particles are repelled from the polymer surface; this effect is called the formation exclusion zone (EZ), and the EZ size amounts to several hundred microns. However, still no one has investigated the EZ formation in a cell whose dimension is close to the EZ size. It was also shown that, upon swelling in water...

Theories of liquids and their simulation ignore any physical effects of dissolved atmospheric gas. Solubilities appear far too low to matter. Long standing observations to the contrary, like cavitation, the salt dependence of bubble-bubble interactions and the stability of degassed emulsions continue to call that assumption into question. And they...

The Casimir force between two ideal conducting surfaces is a special (zero temperature) limit of a more general theory due to Lifshitz. The temperature dependent theory includes correlations in coupled quantum and classical fluctuation modes for conducting, dielectric and magnetic media. If the surfaces are at different temperatures, it has been po...

Structural characterization by three complementary methods of laser diagnostics (dynamic light scattering, laser phase microscopy, and laser polarimetric scatterometry) has established that shaking of immunoglobulin G (IgG) dispersions in water and ethanol–water mixtures (36.7 vol %) results in two effects. First, it intensifies the aggregation of...

A study of the effects induced by a weak magnetic field of about 0.4 T on the precipitation of insoluble alkaline earth carbonates is reported. Optical microscopy, X-ray diffraction and fluorescence experiments are employed at 25 °C and 60 °C in either H2O or D2O solutions to explore the role played by temperature and solvent structure on the magne...

Ascorbyl‐6‐O‐oleate (Asc‐OL) was synthesized enzimatically and studied in the pure state and in aqueous dispersions. Small‐angle X‐ray scattering (SAXS), differential scanning calorimetry (DSC), Fourier transformed infrared (FTIR) spectroscopy experiments and antioxidant tests were conducted in order to characterize the compound and to evaluate its...

Hofmeister effects, also known as specific ion effects, are variations in interactions between particles and surfaces or other particles in salt solutions that depend on the specific identity of the ions comprising the salt. Na ⁺ is the dominant cation in physiological fluids, Li ⁺ is used to treat bipolar disorder, K ⁺ is used in lethal injections...

Among the unsolved mysteries of modern biology is the nature of a lining of blood vessels called the ‘endothelial surface layer’ or ESL. In venous micro-vessels, it is half a micron in thickness. The ESL is 10 times thicker than the endothelial glycocalyx (eGC) at its base, has been presumed to be comprised mainly of water, yet is rigid enough to e...

The effect of a natural, biodegradable surfactant obtained using a novel and efficient chemical reaction between cysteine (a thiol-based amino acid) and an octanoyl (C8) compound, was investigated for its application to the ion flotation removal of low levels of different contaminant ions from aqueous solution. The synthesised amino acid-based sing...

Bubbling CO2 through wastewater inactivates viruses and bacteria without the gas being pressurised. It is known that bubbling hot gas through wastewater can effectively sterilise it. CO2 is particularly attractive for this, since large amounts of it are produced at landfill sites, bio-gas plants and coal-powered energy plants, presenting the possib...

The effect of a natural, biodegradable surfactant obtained using a novel and efficient chemical reaction between cysteine (a thiol-based amino acid) and an octanoyl (C8) compound, was investigated for its application to the ion flotation removal of low levels of different contaminant ions from aqueous solution. The syn-thesised amino acid-based sin...

The swelling of a polymer ion-exchange membrane Nafion in water with various heavy isotope contents (D2O) was studied by photoluminescent UV spectroscopy. The photoluminescence arises because of the presence of sulfonic groups attached to the ends of the perfluorovinyl ether groups that form the tetrafluoroethylene (Teflon) backbone of Nafion. The...

The effect of eight potassium salts (KF, K3PO4, KOCN, K2CO3, KCl, K2SO4, KBr and KI) on glycerol carbonate (GC) is studied through NMR, DSC, solubility and ATR-FTIR experiments. From the solubility data, the main thermodynamic functions of solution and solvation are estimated, and the mean molal activity coefficients are calculated. The results sug...

Glycerol carbonate (4-hydroxymethyl-1,3-dioxolan-2-one, shortly GC) is a dense, viscous, water soluble solvent. The high dielectric constant and dipole moment make it a suitable non-aqueous green solvent for several salts in different applications. GC dissolves significant amounts of inorganic salts such as KF. The saturation of GC with KF leads to...

This study compares the effect of using a range of different hot gases to sterilise water at atmospheric pressure within a hot bubble column evaporator (HBCE) reactor. Water containing bacteria (E.coli ATCC 15597) and viruses (MS2 ATCC 15597-B1) was sterilized with 6 different gases (CO2, N2, O2, Ar, air and combustion gas) at inlet temperatures of...

Experiments with Fourier transform spectrometry of Nafion, a water-swollen polymeric membrane, are described. The transmittance spectra of liquid samples and Nafion, soaked in these samples, were studied, depending on the deuterium content in water in the spectral range 1.8–2.15 μm. The experiments were carried out using two protocols: in the first...

Part 1 revisited developments in lipid and surfactant self assembly over the past 40 years [1]. New concepts emerged. Here we explore how these developments can be used to make sense of and bring order to a range of complex biological phenomena. Together with Part 1, this contribution is a fundamental revision of intuition at the boundaries of Coll...

The specific effects induced by some strong electrolytes or neutral cosolutes on aqueous mixtures of guar gum (GG), sodium alginate (SA) and sodium hyaluronate (SH) were studied through rheology and DSC experiments. The results are discussed in terms of changes in the polymer conformation, structure of the network and hydration properties. This stu...

A number of missing factors influence surface forces strongly; so much so that the classical theory is often irrelevant to the real world. Among these factors, dissolved atmospheric gas or other sparsely soluble solutes play a central role in long range hydrophobic forces. Bubble–bubble interactions exhibit unexplained non-Hofmeister ion specificit...

Hofmeister, specific ion effects, hydration and van der Waals forces at and between interfaces are factors that determine curvature and microstructure in self assembled aggregates of surfactants and lipids; and in microemulsions. Lipid and surfactant head group interactions and between aggregates vary enormously and are highly specific. They act on...

In the treatment of household wastewater viruses are hard to eliminate. A new technique is described which tackles this major problem. The MS2 (ATCC15597-B1) virus was used as a surrogate to estimate the inactivation rates for enteric viruses by a hot (150 °C) air bubble column evaporator (HBCE) system Its surface charging properties obtained by dy...

Ion-stabilized nanobubbles in bulk aqueous solutions of various electrolytes were investigated. To understand the ion-specific mechanism of nanobubble stabilization, an approach based upon the Poisson - Boltzmann equation at the nanobubble interface and in the near-surface layer was developed. It has been shown that the stabilization of nanobubbles...

The ion specificity of bubble-bubble interactions in water remains unexplained. Whatever their valence all ion pairs either completely inhibit bubble coalescence or have no effect whatever. The phenomenon appears unrelated to Hofmeister specificity. Salts which inhibit coalescence enable the formation of a high density bubble column evaporator (BCE...

The phase behavior of mixtures of a typical insect pheromone (olean) and a phospholipid (DOPC)/water dispersion is extensively explored through SAXS, NMR and DSC experiments. The results mimic those obtained with anaesthetics in phospholipid/water systems. They also mimic the behavior and microstructure of ternary mixtures of membrane mimetic, bila...

The specific ion effect on the kinetics of iodination of acetone in an acidic medium is investigated through UV-vis spectrophotometry as a function of the nature of the acid and of temperature. The results indicate that the order of the reaction with respect to acetone is practically unaffected by the composition of the acid while the value of the...

The occurrence of Hofmeister (specific ion) effects in various membrane-related physiological processes is well documented. For example the effect of anions on the transport activity of the ion pump Na+, K+-ATPase has been investigated. Here we report on specific anion effects on the ATP-dependent Ca2+ translocation by the sarcoplasmic reticulum Ca...

A single mathematical theme underpins disparate physical phenomena in classical, quantum and statistical mechanical contexts. This mathematical "correspondence principle", a kind of wave-particle duality with glorious realizations in classical and modern mathematical analysis, embodies fundamental geometrical and physical order, and yet in some sen...

An enhanced thermal decomposition of chemical compounds in aqueous solution has been achieved at reduced solution temperatures. The technique exploits hitherto unrecognized properties of a bubble column evaporator (BCE). It offers better heat transfer efficiency than conventional heat transfer equipment. This is obtained via a continuous flow of ho...

The solubilities of some univalent potassium salts (KF, KCl, KBr, KI, KClO4, KSCN, and KCNO) in propylene carbonate (PC) were determined at different temperatures from (25.0 to 45.0) °C through flame emission spectroscopy. From the solubility measurements, the thermodynamic parameters ∆G 0, ∆H 0 and ∆S 0 of solution were calculated. Measurements we...

The distribution of hydronium and hydroxide ions at the air-water interface has been a problem of much interest in recent years. Here we explore what insights can be gained from a continuum solvent model. We extend our model of ionic solvation free energies and surface interaction free energies to include hydronium and hydroxide. The hydronium cati...

We present theoretical and numerical results for the screened Casimir effect between perfect metal surfaces in a plasma. We show how the Casimir effect in an electron-positron plasma can provide an important contribution to nuclear interactions. Our results suggest that there is a connection between Casimir forces and nucleon forces mediated by mes...

The calculation of ion-ion interactions in water is a problem of long standing importance. Modelling these interactions is a prerequisite to explaining Hofmeister (specific ion) Effects. We here generalize our solvation model[J. Phys. Chem. 2013 117 9421] of ions to calculate the free energy of two ions in water as a function of separation. The sam...

Specific effects with electrolytes have posed a challenge since the 1880’s. The pioneering work was that of Franz Hofmeister who studied specific salt induced protein precipitation. These effects are the rule rather the exception and are ubiquitous in chemistry and biology. Conventional electrostatic theories (Debye-Hückel, DLVO, etc.) cannot expla...

b Specific effects of electrolytes have posed a challenge since the 1880's. The pioneering work was that of Franz Hofmeister who studied specific salt induced protein precipitation. These effects are the rule rather the exception and are ubiquitous in chemistry and biology. Conventional electrostatic theories (Debye– Hü ckel, DLVO, etc.) cannot exp...

Models based solely on electrostatics cannot explain ion specific properties of electrolyte solutions. We give calculations of dispersion interactions of ions with other ions and with water molecules. These are done via ab initio Symmetry Adapted Perturbation Theory with Density Functional Theory (DFT-SAPT). The calculations establish the substanti...

Explaining and predicting the distribution of ions at the air-water interface has been a cen- tral challenge of physical chemistry for nearly a century. In essence the problem amounts to calculating the change in the solvation energy of an ion as it approaches the interface. Here, we generalize our recently developed model of ionic solvation energi...

Continuum solvent models of electrolyte solutions are extremely useful. However, before we can use them with confidence, it is important to test them by comparison with a range of experimental properties. Here, we have adapted our recently developed1,2 simple continuum solvent model of ionic solvation free energies to calculate the solvation entrop...

Turbidity titrations are used to study the ion specific aggregation of hemoglobin (Hb) below and physiological salt concentration in the pH range 4.5−9.5. At a salt concentration 50 mM cations promote Hb aggregation according to the order Rb + > K + ∼ Na + > Cs + > Li +. The cation series changes if concentration is increased, becoming K + > Rb + >...

The dispersion energy is an important contribution to the total solvation energies of ions and neutral molecules. Here, we present a new continuum model calculation of these energies, based on macroscopic quantum electrodynamics. The model uses the frequency dependent multipole polarizabilities of molecules in order to accurately calculate the disp...

Physically accurate continuum solvent models that can calculate solvation energies are crucial to explain and predict the behavior of solute particles in water. Here, we present such a model applied to small spherical ions and neutral atoms. It improves upon a basic Born electrostatic model by including a standard cavity energy and adding a dispers...

The theory is presented for resonance interaction between two atoms in an excited configuration: one atom, the "receptor" of information (i.e. energy), adsorbed on a phospholipid surface and the other atom, the "emitter" of information (i.e. energy), a long distance away. The dielectric function for a specific phospholipid membrane is obtained from...

We present the theory for retarded resonance interaction between two identical atoms at arbitrary positions near a metal surface. The dipole-dipole resonance interaction force that binds isotropically excited atom pairs together in free space may turn repulsive close to an ideal (totally reflecting) metal surface. On the other hand, close to an inf...

Ion specificity is a long standing unsolved puzzle of chemistry and biology. Myriad experiments underline its universality. We have studied ion specific effects on different buffers at the same nominal bulk pH. We used both electrophoretic light scattering and pH measurements to investigate a system constituted by lysozyme dissolved in different bu...

The solubility of some potassium salts (KF, KCl, KBr, KI, KNO3, KClO4, KSCN, and KSeCN) in ethylene carbonate (EC) was determined at different temperatures with an Inductively Coupled Plasma Atomic Emission Spectrometer. From the solubility measurements, the thermodynamic parameters ∆G, ∆H and ∆S, of solution and of solvation, were calculated. Meas...

Experiments on bovine serum albumin (BSA) via potentiometric titration (PT) and electrophoretic light scattering (ELS) are used to study specific ion binding. The effect is appreciable at a physiological concentration of 0.1 M. We found that anions bind to the protein surface at acidic pH - where the protein carries a positive charge (Zp > 0) - acc...

The resonance interaction that takes place in planar nanochannels between pairs of excited state atoms is explored. We consider interactions in channels of silica, zinc oxide and gold. The nanosized channels induce a dramatically different interaction from that in free space. Illustrative calculations for two lithium and cesium atoms, demonstrate t...

There is an attractive Casimir-Lifshitz force between two silica surfaces in a liquid (bromobenze or toluene). We demonstrate that adding an ultrathin (5-50{\AA}) metallic nanocoating to one of the surfaces results in repulsive Casimir-Lifshitz forces above a critical separation. The onset of such quantum levitation comes at decreasing separations...

We consider the interaction between a ZnO nanorod and a SiO2 nanorod in bromobenzene. Using optical data for the interacting objects and ambient we calculate the force (from short-range attractive van der Waals force to intermediate-range repulsive Casimir-Lifshitz force to long-range entropically driven attraction). The nonretarded van der Waals i...

Hofmeister series reversal can occur with change in pH, or increase in salt concentration. The phenomena are a challenge for any theory of ion specific effects. Recent theoretical work predicts how a complex interplay between ionic sizes, hydration and dispersion forces explains Hofmeister series reversal. Electrophoretic mobility measurements on l...

The interaction between two dissimilar surfaces across an electrolyte is re-examined. The focus is on effects of ion-specific dispersion forces missing from classical electrostatic double-layer theory. The pressure between two flat surfaces is derived by two alternate methods (midpoint and whole domain approaches). Significant differences emerge fr...

Hofmeister's work provided significant information about the importance of ion specificity in biology. Specific ion effects occurred in simple aqueous solutions of electrolytes involving properties such as viscosity, density, refractive index, heat capacity, activity coefficient, freezing point depression and boiling point elevation, and osmotic pr...

Casimir forces between surfaces immersed in bromobenzene have recently been measured by Munday et al. Attractive Casimir forces were found between gold surfaces. The forces were repulsive between gold and silica surfaces. We show the repulsion is due to retardation effects. The van der Waals interaction is attractive at all separations. The retarda...

Hydration effects in colloidal interactions or problems involving electrolytes are usually taken care of by effective electrostatic potentials that subsume notions like hydrated ion size, Gurney potentials, soft and hard, chaotropic and cosmotropic ions, and inner and outer Helmholtz planes. Quantum fluctuation (dispersion) forces between ions and...

The points of zero charge/potential of proteins depend not only on pH but also on how they are measured. They depend also on background salt solution type and concentration. The protein isoelectric point (IEP) is determined by electrokinetical measurements, whereas the isoionic point (IIP) is determined by potentiometric titrations. Here we use pot...

Protein solubility studies below the isoelectric point exhibit a direct Hofmeister series at high salt concentrations and an inverse Hofmeister series at low salt concentrations. The efficiencies of different anions measured by salt concentrations needed to effect precipitation at fixed cations are the usual Hofmeister series (Cl(-) > NO(3)(-) > Br...

The first direct measurements of forces between mica surfaces in electrolytes showed an apparent short range repulsion additional to the predictions of DLVO theory. The origins of such “secondary hydration forces” have remained a mystery. We show they can be explained as an repulsive entropic force appearing due to a hydration surface layer with lo...

The classical Derjaguin-Landau-Verwey-Overbeek (DLVO) theory of colloids, and corresponding theories of electrolytes, are unable to explain ion specific forces between colloidal particles quantitatively. The same is true generally, for surfactant aggregates, lipids, proteins, for zeta and membrane potentials and in adsorption phenomena. Even with f...

Adsorption of organic acid at the mineral oxide-electrolyte interface has been explored. The adsorption of 2,4-dihydroxybenzoic acid onto α-alumina illustrates that specific ion effects show up at very low salt concentration (<0.05 mM). These surprising Hofmeister effects occur at salt concentrations an order of magnitude lower than in a previous s...