Surface tension and dilational rheology of mixed β-casein – β-lactoglobulin aqueous solutions at the water/air interface

2020 ◽  
Vol 106 ◽  
pp. 105883 ◽  
Author(s):  
V.B. Fainerman ◽  
E.V. Aksenenko ◽  
A.V. Makievski ◽  
D.V. Trukhin ◽  
S. Yeganehzad ◽  
...  
Keyword(s):  
Surface Tension ◽  
Aqueous Solutions ◽  
Air Interface ◽  
Β Lactoglobulin ◽  
Dilational Rheology

scholarly journals Effectiveness of lactate-containing processing aids application in vegetable treatment

2019 ◽  
Vol 48 (2) ◽  
pp. 28-35
Author(s):  
Вера Евелева ◽  
Vera Eveleva ◽  
Татьяна Черпалова ◽  
Tatyana Cherpalova ◽  
Елена Шиповская ◽  
...  
Keyword(s):  
Surface Tension ◽  
Aqueous Solutions ◽  
Storage Stability ◽  
Raw Materials ◽  
Physical Parameters ◽  
Air Interface ◽  
Deep Layers ◽  
New Processing ◽  
Vegetable Raw Materials ◽  
Processing Aids

Common characteristic of salad products is presence of cut raw vegetables in its composition. Cold cutting helps surface microorganisms penetrate into deep layers of the product. Hygienic cleanliness of raw ingredients is the major factor which contributes to storage stability of salad products. One of the most effective methods that helps enhance salad storage stability is initial treatment of vegetable raw materials with antimicrobial solutions. The author presents information on using solutions of hydrogen peroxide and peroxyacetic acid, sodium hypochlorite and compositions containing peroxide compounds and acetic, benzoic, sorbic, ascorbic, citric, lactic and other acids as well as their salts and containing guanidylic compounds. The article reveals that antimicrobial action of lactate-containing processing aids improves sufficiently if polymer cation-active compounds are introduced into their composition. The goal of the research is to study application effectiveness of new processing aids for treatment of raw peeled cut vegetables to reduce bacterial content and enhance storage stability before thermal treatment (boiling). The author tested the aids based on lactate-containing components. Physicochemical and physical parameters of the aids and their aqueous solutions are the following: active acidity (pH), titratab6le acidity, water and volatiles mass fraction, dynamic viscosity, surface tension. The article presents the data which characterize change in surface tension of aqueous solutions of the aids at the water-air interface depending on their concentration. It also gives quality indicators and microbial parameters of raw peeled cut vegetables after their processing with solutions of the aids. It was found out that treatment of raw peeled cut vegetables with processing aids based on lactate containing components prolongs their shelf life from 3 hours according to the applicable technology up to 48 hours.

scholarly journals Prediction of Aqueous Solution Surface Tension of Some Surfactant Mixtures and Composition of Their Monolayers at the Solution–Air Interface

2021 ◽  
Vol 5 (4) ◽  
pp. 53
Author(s):  
Bronisław Jańczuk ◽  
Anna Zdziennicka ◽  
Katarzyna Szymczyk ◽  
Maria Luisa González-Martín
Keyword(s):  
Aqueous Solution ◽  
Surface Tension ◽  
Aqueous Solutions ◽  
Ternary Mixtures ◽  
Mixture Component ◽  
Surfactant Mixtures ◽  
Surface Tension Reduction ◽  
Air Interface ◽  
Binary And Ternary Mixtures ◽  
Solution Surface

Measurements of the surface tension of the aqueous solution of SDDS mixture with fluorocarbon surfactants (FC) were carried out and considered in light of the surface tension of aqueous solutions of individual surfactants. Similar analyses were made for many other aqueous solutions of binary and ternary mixtures, taking into account the literature data of the surface tension of aqueous solutions of TX100, TX114, TX165, SDDS, SDS, CTAB, CPyB and FC. The possibility of predicting the surface tension of the aqueous solution of many surfactant mixtures from that of the mixture components using both the Szyszkowski, Fainerman and Miller and Joos concepts was analyzed. The surface tension of the aqueous solutions of surfactant mixtures was also considered based on the particular mixture component contribution to the water surface tension reduction. As a result, the composition of the mixed surface layer at the solution–air interface was discussed and compared to that which was determined using the Hua and Rosen concept. As follows from considerations, the surface tension of the aqueous solution of binary and ternary surfactant mixtures can be described and/or predicted.

scholarly journals Adsorption Properties of Hydrocarbon and Fluorocarbon Surfactants Ternary Mixture at the Water-Air Interface

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4313
Author(s):  
Bronisław Jańczuk ◽  
Katarzyna Szymczyk ◽  
Anna Zdziennicka
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Standard Free Energy ◽  
Ternary Mixtures ◽  
Free Energy Of Adsorption ◽  
Interface Tension ◽  
Air Interface ◽  
Surface Excess Concentration ◽  
Tail Water ◽  
Triton X

Measurements were made of the surface tension of the aqueous solutions of p-(1,1,3,3-tetramethylbutyl) phenoxypoly(ethylene glycols) having 10 oxyethylene groups in the molecule (Triton X-100, TX100) and cetyltrimethylammonium bromide (CTAB) with Zonyl FSN-100 (FC6EO14, FC1) as well as with Zonyl FSO-100 (FC5EO10, FC2) ternary mixtures. The obtained results were compared to those provided by the Fainerman and Miller equation and to the values of the solution surface tension calculated, based on the contribution of a particular surfactant in the mixture to the reduction of water surface tension. The changes of the aqueous solution ternary surfactants mixture surface tension at the constant concentration of TX100 and CTAB mixture at which the water surface tension was reduced to 60 and 50 mN/m as a function of fluorocarbon surfactant concentration, were considered with regard to the composition of the mixed monolayer at the water-air interface. Next, this composition was applied for the calculation of the concentration of the particular surfactants in the monolayer using the Frumkin equation. On the other hand, the Gibbs surface excess concentration was determined only for the fluorocarbon surfactants. The tendency of the particular surfactants to adsorb at the water-air interface was discussed, based on the Gibbs standard free energy of adsorption which was determined using different methods. This energy was also deduced, based on the surfactant tail surface tension and tail-water interface tension.

scholarly journals β-Lactoglobulin Adsorption Layers at the Water/Air Surface: 5. Adsorption Isotherm and Equation of State Revisited, Impact of pH

2021 ◽  
Vol 5 (1) ◽  
pp. 14
Author(s):  
Georgi G. Gochev ◽  
Volodymyr I. Kovalchuk ◽  
Eugene V. Aksenenko ◽  
Valentin B. Fainerman ◽  
Reinhard Miller
Keyword(s):  
Theoretical Description ◽  
Fluid Interfaces ◽  
Interfacial Behavior ◽  
Current State ◽  
Air Interface ◽  
Direct Measurements ◽  
Wide Range ◽  
Dilational Viscoelasticity ◽  
Parameter Values ◽  
Β Lactoglobulin

The theoretical description of the adsorption of proteins at liquid/fluid interfaces suffers from the inapplicability of classical formalisms, which soundly calls for the development of more complicated adsorption models. A Frumkin-type thermodynamic 2-d solution model that accounts for nonidealities of interface enthalpy and entropy was proposed about two decades ago and has been continuously developed in the course of comparisons with experimental data. In a previous paper we investigated the adsorption of the globular protein β-lactoglobulin at the water/air interface and used such a model to analyze the experimental isotherms of the surface pressure, Π(c), and the frequency-, f-, dependent surface dilational viscoelasticity modulus, E(c)f, in a wide range of protein concentrations, c, and at pH 7. However, the best fit between theory and experiment proposed in that paper appeared incompatible with new data on the surface excess, Γ, obtained from direct measurements with neutron reflectometry. Therefore, in this work, the same model is simultaneously applied to a larger set of experimental dependences, e.g., Π(c), Γ(c), E(Π)f, etc., with E-values measured strictly in the linear viscoelasticity regime. Despite this ambitious complication, a best global fit was elaborated using a single set of parameter values, which well describes all experimental dependencies, thus corroborating the validity of the chosen thermodynamic model. Furthermore, we applied the model in the same manner to experimental results obtained at pH 3 and pH 5 in order to explain the well-pronounced effect of pH on the interfacial behavior of β-lactoglobulin. The results revealed that the propensity of β-lactoglobulin globules to unfold upon adsorption and stretch at the interface decreases in the order pH 3 > pH 7 > pH 5, i.e., with decreasing protein net charge. Finally, we discuss advantages and limitations in the current state of the model.

scholarly journals Surface Thermodynamics, Viscosity, Activation Energy of N-Methyldiethanolamine Aqueous Solutions Promoted by Tetramethylammonium Arginate

Entropy ◽  
2020 ◽  
Vol 22 (12) ◽  
pp. 1337
Author(s):  
Xiangfeng Tian ◽  
Lemeng Wang ◽  
Pan Zhang ◽  
Dong Fu
Keyword(s):  
Activation Energy ◽  
Surface Tension ◽  
Diffusion Coefficient ◽  
Aqueous Solutions ◽  
Quantitative Relationship ◽  
Viscosity Data ◽  
Surface Thermodynamics ◽  
Surface Entropy ◽  
Operation Conditions ◽  
Surface Enthalpy

The surface tension and viscosity values of N-methyldiethanolamine (MDEA) aqueous solutions promoted by tetramethylammonium arginate ([N1111][Arg]) were measured and modeled. The experimental temperatures were 303.2 to 323.2 K. The mass fractions of MDEA (wMDEA) and [N1111][Arg] (w[N1111][Arg]) were 0.300 to 0.500 and 0.025 to 0.075, respectively. The measured surface tension and viscosity values were satisfactorily fitted to thermodynamic models. With the aid of experimentally viscosity data, the activation energy (Ea) and H2S diffusion coefficient (DH2S) of MDEA-[N1111][Arg] aqueous solution were deduced. The surface entropy and surface enthalpy of the solutions were calculated using the fitted model of the surface tension. The quantitative relationship between the calculated values (surface tension, surface entropy, surface enthalpy, viscosity, activation energy, and H2S diffusion coefficient) and the operation conditions (mass fraction and temperature) was demonstrated.

The Chorionic Plastron and its Role in the Eggs of the Muscinae (Diptera)

1960 ◽  
Vol s3-101 (55) ◽  
pp. 313-332
Author(s):  
H. E. HINTON
Keyword(s):  
Surface Tension ◽  
High Pressures ◽  
Middle Layer ◽  
Clean Water ◽  
Active Materials ◽  
Great Resistance ◽  
Plane Normal ◽  
Air Interface ◽  
Surface Active ◽  
Egg Shell

In flies of the subfamily Muscinae the egg-shell has both an outer and an inner meshwork layer, each of which holds a continuous film of air. Between these two meshwork layers there is a more or less thick middle layer to which the shell chiefly owes its mechanical strength. Holes or aeropyles through the middle layer effect the continuity of the outer and inner films of air. Both meshwork layers consist of struts that arise perpendicularly from the middle layer. In both layers the struts are branched at their apices in a plane normal to their long axes. These horizontal branches form a fine and open hydrofuge network that provides a large water-air interface when the egg is immersed. When it rains or when the egg is otherwise immersed in water, the film of air held in the outer meshwork layer of the shell funtions as a plastron. To be an efficient respiratory structure a plastron must resist wetting by both the hydrostatic pressures and the surface active materials to which it is normally exposed. The plastrons of all the Muscinae tested resist wetting in clean water by pressures far in excess of any they are likely to encounter in nature. The resistance of a plastron to hydrostatic pressures varies directly as the surface tension of the water, and the surface tension of water in contact with the decomposing materials in which the Muscinae lay their eggs is much lowered by surface active materials. These considerations seem to provide an explanation for the great resistance of the plastron of the Muscinae to wetting by excess pressures and for the paradox that the plastrons of these terrestrial eggs are more resistant to high pressures than are the plastrons of some aquatic insects that live in clean water.

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