Viscosity Of Aqueous Solutions Research Articles

Density and Viscosity Measurements and Modeling of CO2-Loaded and Unloaded Aqueous Solutions of Potassium Lysinate

This paper reports new experimental data and calibrated semiempirical correlations concerning the density and viscosity of aqueous solutions of potassium lysinate (LysK), a promising bio-based solv...

The Synthesis of Associative Copolymers with Both Amphoteric and Hydrophobic Groups and the Effect of the Degree of Association on the Instability of Emulsions.

The acrylamide (AM)/methacryloyl ethyl sulfobetaine (SPE)/behenyl polyoxyethylene ether methacrylate (BEM) terpolymer (PASB) was synthesized by soap-free emulsion polymerization. Four types of PASBs were synthesized by adjusting the moles of AM and BEM with constant total moles of monomers. The synthesized copolymers were characterized by Fourier-transform infrared spectroscopy, thermogravimetry, molecular weight, and viscosity. By measuring the microscopic morphology and backscattered light intensity of the emulsions, the instability process of the emulsions prepared by PASBs was investigated in detail. The main instability processes of the emulsions prepared from PASBs within 45 min were flocculation and coalescence. The intermolecular association of copolymer PASBs was dominated by the behenyl functional groups on the molecular chains. The stability of the emulsions, which were prepared from isoviscosity aqueous solutions controlled by the concentration of the associative copolymers, was increased with the degree of association of copolymers. The hydrophobic association between the copolymer molecules can further slow down the flocculation and coalescence of the emulsion droplets on the basis of the same aqueous solution viscosity, which is one of the reasons for improving the stability of the emulsion.

Functional and technological properties of food additive "Magnetofood" in production of shaped jelly marmalade on agar and pectin

Jelly and marmalade products are "lyophilic colloids" – lyophilic colloidal-dispersed, ie microheterogeneous (multi- or polyphasic) systems based on high molecular weight compounds (gelatin, pectin, agar, etc.). Therefore, the problem of stabilizing their polyphasic structure is relevant. In addition, the expansion and improvement of the production of jelly and marmalade products requires the search for simplified resource- and energy-saving technology, increasing the stability of the colloidal disperse system, improving the quality and extending the shelf life of finished products. Promising technological applications have food additives in the nanometer range, due to specific and stable physical and chemical parameters, a wide range of functional and technological properties. The paper proposes the solution of the problem of stabilization of the polyphase structure of jelly-marmalade products and the formation of their quality by using the food additive "Magnetofood" (based on double oxide of divalent and trivalent iron: FeO×Fe2O3). "Magnetofood" - highly dispersed powder with a particle size (70–80) nm, which has a fairly diverse functional and technological potential: high ζ-potential and surface activity; clusterophilicity and amphiphilicity; complexing, thickening, structuring, stabilizing, thixotropic properties. This allows us to recommend "Magnetofood" as a food additive of complex action to improve the quality and prolong the shelf life of jelly-marmalade products, in particular jelly-shaped marmalade. The surface-active properties of nanoparticles of the food additive "Magnetofood" are determined: a rather significant value of ζ-potential (34-44) mV, amphiphilicity (marginal wetting angle Q<90o by polar-nonpolar medium) - show signs of stability and stability on polyphasic colloidal-dispersed systems , which increases in acidic environments, in solutions of polysaccharides, proteins on average by (55±)%, which is due to clusterophilicity and self-organization of nanoparticles "Magnetofood" into electrostatic complexes with proteins, polysaccharides and their spatial structuring. It was found that the addition of "Magnetofood" in the mass fraction (0,10–0,20)% to the mass of the structurant increases the viscosity of aqueous solutions of gelling agents in (1,22–1,27) times for agar and in (1,24–1,29) times for pectin and the rate of structuring of gel masses in (1,73±0,01) times for agar and in (1,67±0,01) times for pectin due to the structure-forming action of nanoparticles "Magnetofood". In addition, the ability of the gel structure to thixotropy increases by (1,4–1,5) times and the mechanical strength of the gel well by (1,32–1,80) times for agar and (1,49–1,57) times for pectin due to the stabilizing action of Magnetofood nanoparticles, which allows to reduce the amount of gelling agent by (9.0–11.0)% for agar and by (7.0–9.0)% for pectin.

Amino Ethers of Ortho-Phosphoric Acid as Extragents for Ethanol Dehydration

Amino ethers of ortho-phosphoric acid prepared using triethanolamine; ortho-phosphoric acid; polyoxyethylene glycol, diethylene glycol, triethylene glycol and glycerol (AEPA-DEG/TEG/Gl) were investigated as extractants for the separation of aqueous ethanol solutions by extractive distillation. Using the method of open evaporation, the influence of the molecular structure of AEPA-DEG/TEG/Gl on the conditions of vapor–liquid equilibrium in ethanol–water solutions was studied. It has been shown that the addition of AEPA-DEG/TEG/Gl removes the azeotropic point. At the same time, the observed effect turned out to be significantly higher in comparison with the use of pure glycerol or glycols for these purposes. The UNIFAC model was used to calculate the activity coefficients in a three-component ethanol–water–AEPA-DEG/TEG/Gl mixture. Within the framework of this model, a division of AEPA-DEG/TEG/Gl molecules into group components is proposed. Previously unknown parameters of the groups PO–CH, PO–CH2, PO–OCH2, PO–NHCH2, PO–OH, and PO–H2O were determined from our own and published experimental data. The concentration dependences of the density and dynamic viscosity of AEPA-Gl aqueous solutions have been experimentally measured. Experimental studies of the extractive distillation of ethanol–water using AEPA-Gl as an extractant have been carried out in a column with bubble cap plates and a packing, and its high efficiency has been established.

Viscosity of Aqueous Solutions of Polyacrylic and Polymethacrylic Acids in a Magnetic Field

Viscosity of Aqueous Solutions of Polyacrylic and Polymethacrylic Acids in a Magnetic Field

Using the negative hydration of inorganic salt ions to improve the properties of Alkali-activated slag cement in plastic stage

Alkali-activated slag (AAS) cement is a low-carbon environmentally friendly cementitious material. Water glass (WG) activated slag cement has excellent physical and mechanical properties, but it is not conducive to the construction due to its rapid setting and hardening, easy loss of fluidity. Negative hydration ions can reduce the viscosity of aqueous solution. So, in the present paper, inorganic salt composed of negative hydration ions were used to adjust the fluidity and setting time of AAS paste. The results show that with the increase of NaCl, KCl, KBr and KNO3, the initial fluidity of AAS paste increases slightly, and the 30 min fluidity increases a lot, while the fluidity at 60 min is greatly affected by the amount of inorganic salt. KNO3 shows the greatest initial fluidity increase. When 0.2% Ba(NO3)2 is added with other four inorganic salts, the fluidity retention is significantly improved, especially the fluidity of 60 min. When 5% NaCl, KCl, KBr and KNO3 respectively mixed with 0.2% Ba(NO3)2 are added, the fluidity retention of AAS paste at 60 min are 97.4%, 92.7%, 100%, 82.5% respectively. Compared with the AAS paste without inorganic salt, when 5% NaCl, KCl, KBr and KNO3 respectively blended with 0.2% Ba(NO3)2 are added, the initial setting time increase by 228.6%, 285.7% 307.1% and 239.3%, while the final setting time increase by 175.6%, 222.0%, 231.7% and 178.0% respectively. With the inorganic salt, the ζ-potential of the originally negative AAS cement suspension become more negative, both yield stress and plastic viscosity coefficient decease, especially the plastic viscosity coefficient greatly reduces. This may be the reason for the change of fluidity and setting time of AAS paste.

Modulation of the Viscosity of Guar-Based Fracking Fluids Using Salts

Fracking is an enhanced oil recovery technology, which uses viscoelastic fluids (fracking fluids) to fracture oil reservoirs and to transport sand within the fractures, to prop them open. This technology enables oil recovery from scarcely permeable formations. Fractured formations release saline water over time. This saline water (called “produced water”) is discarded rather than used to produce fracking fluids because it can decrease fracking fluid viscosity. Nonetheless, it would be advantageous to use produced water to reduce freshwater consumption and wastewater production. Our study analyzes the effect of chloride salts (CaCl2, MgCl2, and Fe(III)Cl) and of sulfate salts (MgSO4 and FeSO4) at different concentrations (0.05–1 M) on the viscosity of aqueous guar solutions. All chloride salts tested increase the viscosity of guar solutions in the concentration range analyzed and promote the formation of small guar aggregates. At 0.05 M concentrations, MgSO4 has effects similar to chloride salts. In contrast, 1 M MgSO4 decreases the viscosity of guar solutions. FeSO4 also decreases the viscosity of aqueous guar solutions, at either 0.05 or 1 M concentrations. The decrease in viscosity of guar solutions is attributed to large guar aggregate formation (as opposed to a cohesive network). Sodium cocoyl glutamate (SCG) increases the viscosity of non-cross-linked guar solutions and the shear viscoelastic moduli of guar solutions cross-linked with sodium tetraborate. Specifically, SCG restores the viscosity of guar solutions with MgSO4 and increases it above values measured in deionized (DI) water in the presence of MgCl2. Attenuated total reflectance–Fourier transform infrared (ATR-FTIR) spectroscopy shows that hydrogen bonding was more significant in guar + SCG + 0.7 M MgCl2 samples than in guar + SCG + 0.7 M MgSO4, indicating that the formation of a hydrogen-bonded network was correlated to high viscosity. ATR-FTIR also indicates that MgSO4 weakened hydrogen bonding of water clusters, whereas SCG restored it, enabling guar hydration even in the presence of MgSO4. Our study highlights which salts are most problematic (e.g., FeSO4) and proposes a potential additive (SCG) to enhance the viscosity of guar in the presence of selected salts (e.g., magnesium salts) by promoting hydrogen bonding.

Multiple roles of graphene nanoparticles (GNP) in microbubble flotation for crude oil recovery from sand

Known for their high oil adsorption, hydrophobic properties and easy manufacturing, graphene nanoparticles (GNP) have been vastly studied in various applications. This study aims to investigate the effects of adding GNP into the flotation process to enhance oil recovery efficiency from oil-contaminated sand. The oil removal efficiency was tested in a laboratory-scale flotation process against various parameters including pH, GNP concentration and temperature. A maximum oil recovery efficiency of 70.4% was achieved at the optimum operating conditions of pH 7, 0.1 wt% of GNP and system temperature of 80 °C. Coherently, zeta potential measurements of GNP and microbubble showed that optimum graphene-microbubble attachment would occur at pH 6 to 7. This suggests that there is a preferential GNP-microbubble attachment that encourages oil-GNP-microbubble attachment during flotation. Interfacial tension was at its lowest at 0.1 wt% of GNP where maximum oil recovery was recorded. The reduced interfacial tension enhances both oil-microbubble attachment and oil-sand separation. On a different note, an increase in GNP concentration showed minimal changes on the viscosity and pH of the GNP aqueous solution. This is especially beneficial during post-treatment of the sand, in which restoring the original sand pH is not required.

ТЕХНОЛОГІЯ БОРОШНЯНИХ ВИРОБІВ ГРУЗИНСЬКОЇ КУХНІ З ВИКОРИСТАННЯМ АГЛЮТЕНОВОГО БОРОШНА

The article highlights the relevance of the development of flour products of Georgian cuisine using gluten-free flour. The technology of gluten – free khachapuri with cheese with the use of gluten – free types of flour – corn, rice and structurants – corn starch and a complex of polysaccharides of flax is substantiated. Traditional khachapuri technology involves the use of wheat flour, which cannot be used in the production of gluten products due to the presence of gluten in gluten proteins. However, according to previous research, other types of gluten-free flour can be effectively used in the production of gluten-free products – corn, rice in combination with effective structuring agents – starch, non-starch polysaccharides. In this regard, we proposed in the production of yeast dough for khachapuri to use a flour mixture of corn and rice flour in combination with corn starch and flaxseed flour, which is characterized by a complex of polysaccharides – cellulose, insoluble polymers of phenolic slime, lime. The share of dietary fiber is up to 28% by weight of flax seeds or non-fat flaxseed flour. Dietary fiber helps to stimulate the intestines in constipation, play a positive role in reducing the risk of coronary heart disease, preventing bowel cancer, reducing obesity. Flaxseed mucus has a well-defined ability to swell, and therefore show high viscosity in aqueous solution or suspension. The hydrocolloid nature of the mucus has a beneficial effect on the water-binding and emulsifying properties of flaxseed flour. The developed products are characterized by high quality and competitiveness, they can be offered for health nutrition of various segments of the population, and nutrition of patients with gluten enteropathy. Due to the high content of dietary fiber, in particular valuable for the prevention of cardiovascular disease, obesity and colon cancer soluble fiber flax flour, it can be recommended for the health of people I work in toxic industries and live in environmentally polluted areas.

ОПРЕДЕЛЕНИЕ КОМПЛЕКСА ТЕПЛОФИЗИЧЕСКИХ СВОЙСТВ ВОДНЫХ РАСТВОРОВ БОРНОЙ КИСЛОТЫ ПРИ ПАРАМЕТРАХ ХАРАКТЕРНЫХ ДЛЯ АВАРИЙНОГО РЕЖИМА ВВЭР

The article presents the results of experimental studies of the thermophysical (density, viscosity) and physicochemical (degree of acidity - pH) properties of water solutions of boric acid. A review of the available literature data on the effect of the properties of boric acid solutions on heat removal from the reactor core is presented. It has been established that the available information is very general and does not cover the entire range of parameters (temperature, pressure, acid concentration) characteristic of a possible emergency at a nuclear power plant with a VVER reactor. Methods and facilities for conducting experimental studies are described. The results of experimental studies are presented. The density of aqueous solutions of boric acid with a concentration of 2.5-450 g/kg H2O at a temperature of 25-130 °C was determined. The dependence of the investigated characteristic on temperature and concentration was also obtained. The results of an experimental study of the kinematic viscosity of water solutions of boric acid with a concentration of 2.5-200 g/kg H2O at a temperature of 25-90 °C were obtained. The total error in measuring the viscosity of aqueous solutions of boric acid did not exceed 2 %. The pH values of water solutions of boric acid in the temperature range 25-50 and concentrations of 2.5-450 g/kg H2O were determined. The dependence for calculating the degree of acidity of boric acid is obtained. Experimental data on the thermophysical and physicochemical properties of water solutions of boric acid can be used to refine the results of calculations of emergency heat removal processes in a reactor facility, carried out using both one-dimensional calculation programs and three-dimensional CFD codes.

The pursuit of a more powerful thermodynamic hydrate inhibitor than methanol. Dimethyl sulfoxide as a case study

Search for new, more effective hydrate formation inhibitors is one of the oil and gas industry's urgent tasks. Dimethyl sulfoxide (DMSO) can be considered as a promising anti-hydrate reagent. DMSO and its aqueous solutions were characterized by several physicochemical methods, including measuring their density, viscosity, freezing point, the methane hydrate equilibrium conditions (V-Lw-H), and identification of the hydrate type formed. The hydrate phase equilibria in the system of DMSO aqueous solution–gaseous methane were determined for a wide range of DMSO concentrations (0–55 mass%), temperatures (242–289 K), and pressures (3–13 MPa). X-ray measurements reveal that DMSO does not form double hydrate with methane over the entire concentration range. The data obtained show that DMSO is a thermodynamic hydrate inhibitor. To quantitatively describe the anti-hydrate activity of DMSO, a correlation of thermodynamic depression ΔTh with the mass fraction of DMSO in solution and gas pressure was proposed. It was found that at concentrations above 33 and 53 mass% DMSO becomes more effective THI than the widely used monoethylene glycol and methanol, respectively. Such behavior is associated with the greater non-ideality of DMSO aqueous solutions (negative deviations from Raoult's law) compared to alcohols aqueous solutions. A linear correlation linking the depression of hydrate equilibrium temperature ΔTh and ice freezing point ΔTice was also derived.A comparative analysis of the density and kinematic viscosity of aqueous solutions of DMSO and methanol (0–100 mass%) was performed. It was revealed that DMSO is a promising inhibitor combining high anti-hydrate activity, low volatility (compared to methanol), and acceptable viscosity properties of aqueous solutions.

Styrene intermolecular associating incorporated-polyacrylamide flooding of crude oil in carbonate coated micromodel system at high temperature, high salinity condition: Rheology, wettability alteration, recovery mechanisms

Polymer flooding is one of the most well-known research interests in the enhanced oil recovery (EOR) due to the excess oil production and limited petroleum reserve. Commercial polymers such as polyacrylamide (PAM) and its hydrolyzed form (HPAM) can be easily degraded at high temperature, high salinity, and high shear rate in attempt to the EOR purposes for the harsh reservoir conditions. In this work, a hydrophobically modified copolymer consisting of acrylamide and styrene (HSPAM) was produced via inverse emulsion polymerization as a wettability modifier and viscosifying agent, applicable under harsh reservoir conditions to direct insights into the synergic oil recovery pore scale mechanisms and overcoming the aforementioned challenges through the EOR process. In the first part of this study, a set of analytical techniques including FTIR, NMR, TGA, and molecular weight measurement was carried out, confirming successfully incorporation of styrene monomer in water-soluble skeleton and higher thermal resistivity of HSPAM compared with HPAM. By analyzing the rheological behavior of HSPAM under harsh reservoir conditions, it was found that the viscosity of HSPAM aqueous solution was increasingly influenced by the total dissolved solids, even up to 40,572 mg/L. In the second part, stability tests, contact angle (CA), interfacial tension (IFT), and carbonate coated glass micromodel flooding experiments were conducted by deionized water (DIW), seawater (SW) and formation brine (FB) in the absence and presence of HSPAM and HPAM. HSPAM illustrated a great stability in seawater and formation brine in comparison with HPAM after 120 days at 80 °C. The presence of HSPAM in seawater resulted in a more water-wet state up to 42° compared to HPAM by contact angle of 31° after 72 h. Findings provided synergic oil recovery mechanisms approved by emulsification and coalition phenomena to show a better wettability alteration and IFT reduction for HSPAM in spite of HPAM alongside drastically improving the brine-based flooding performance, yielding an ultimate recovery of about 82% original oil in place (OOIP).

Dependence of intrinsic viscosity and molecular size on molecular weight of partially hydrolyzed polyacrylamide

AbstractAs a typical water‐soluble polymer, ultra‐high molecular weight (UHMW) partially hydrolyzed polyacrylamide (HPAM) has been widely used in various industries as thickeners or rheology modifiers. However, precise determination of its critical physical parameters such as molecular weight, radius of gyration (Rg) and hydrodynamic radius (Rh) were less documented due to their high viscosity in aqueous solution. In this work, the molecular structure of five UHMW‐HPAM samples with different MW was elucidated by 1H and 13C NMR spectroscopy, and their solution properties were characterized by both static and dynamic light scattering. It is found that all the second virial coefficient (A2) values are positive and approaching zero, indicating of a good solvent of 0.5 M NaCl for UHMW‐HPAM. The weight‐average molecular weight (Mw) dependence of molecular size and intrinsic viscosity [η] for these series of HPAM polymers with MW ranging from 4.81 to 15.4 × 106 g·mol−1 can be correlated as Rg = 3.52 × 10−2Mw0.51, Rh = 1.97 × 10−2Mw0.51, and [η] = 6.98 × 10−4 Mw0.91, respectively. These results are helpful in understanding the relationship between molecular weight and coil size of HPAM polymers in solution, and offer references for quick estimation of molecular weight and screening of commercial UHMW‐HPAM polymers for specific end‐users.

Density and Viscosity of Aqueous (Ammonia + Carbon Dioxide) Solutions at Atmospheric Pressure and Temperatures between 278.15 and 318.15 K

The density and the viscosity of aqueous (NH3 + CO2) solutions have been measured at atmospheric pressure over a temperature range of 278 to 318 K and apparent concentrations of solute between 4 and 10 molNH3 kgH2O–1 for NH3 and between 1 and 5.2 molCO2 kgH2O–1 for CO2. Solute loss from the aqueous solution associated with the high equilibrium partial pressure of NH3 and of CO2 has been limited by devices and protocols developed ad-hoc for sample preparation and density and viscosity measurement. Solid or vapor formation out of the initial liquid mixture has been avoided by means of a thermodynamic model-driven design of experiments. The experimental values gathered in this work have been used to obtain empirical models of density and viscosity, as a function of the apparent concentration of solutes, that is, NH3 and CO2, and temperature, that are able to reproduce the experimental values in all cases with deviations below 1.1% for density and below 9.4% for viscosity. While it is the first time that, to our knowledge, experimental viscosity data of aqueous ammonia solutions loaded with CO2 are added to the literature, the density model developed in this work is also able to reproduce experimental density data from literature with deviations below 1.5%, even outside the boundaries of the experimental conditions considered in this work.

Effect of pH on the flaxseed (Linum usitatissimum L. seed) mucilage extraction process

Water-soluble mucilage extracted from flaxseed has excellent hydrocolloid potential in gel formation; moreover, it can become a product of high technological value in the food, pharmaceutical and cosmetic industries because it has high viscosity in aqueous solution. The aim of the current study is to investigate the effect of extraction medium pH on extraction yield and soluble fiber content. In addition, the purification step effect was evaluated through Fourier transform infrared spectroscopy (FTIR). Extractions were carried out at 3 different pH values (3.81, 6.75 and 9.69) for 13.25 h at 45 oC. The highest yield was recorded at pH 6.75; the highest soluble fiber content was found at pH 3.81. It was possible seeing that the extraction of flaxseed macromolecules in basic medium (pH 9.69) presented the best quality in comparison to other extractions. The purification step based on precipitation with ethanol did not fully remove impurities from the samples.

Thermo- and CO2-triggered viscosifying of aqueous copolymer solutions for gas channeling control during water-alternating-CO2 flooding

Water-alternating-CO2 gas (WAG) flooding is a common technique to enhance oil recovery via improving CO2 sweep efficiency, but serious gas channeling may still occur, especially in reservoirs with strong heterogeneity, due to a poor blocking capacity of aqueous slugs to the “channeling” pathway induced by their low viscosity. Herein, a copolymer whose aqueous solution viscosity can be increased by both heat and CO2 was developed and added into the aqueous slug to control gas channeling and increase oil recovery during enhanced WAG processes. The copolymer was synthesized by grafting poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) onto the triblock copolymer, Pluronic F127, PEO100-PPO65-PEO100. The aqueous copolymer solutions can be thickened/gelled by heating due to the formation of micelles as the physical cross-link and their entanglements even at a concentration as low as 0.2 wt%, and viscosified by bubbling CO2 thanks to expanded copolymer coils caused by electrostatic repulsion-induced chain extension of protonated PDMAEMA chains. Notably, thermo- and CO2-triggered viscosifying can work synergistically and they are completely reversible upon cyclically heating/cooling the copolymer solutions and bubbling/removing CO2 into/from the aqueous phase, respectively. In WAG flooding tests using two parallel cores, gas channeling was mitigated by blocking high-permeability cores due to in-situ thermo-induced gelation and CO2-triggered thickening of copolymer slugs, thus diverting chase fluids into unswept low-permeability cores and enhancing 21–22% total oil recovery than the conventional and HAPM-enhanced WAG modes. Importantly, owing to the characteristics of low initial viscosity, single component, and thermo-gelation, this dually-responsive copolymer possesses high injectivity and satisfactory gelation control. This work could enlighten the design of novel dual/multiple stimuli-thickening polymers used for channeling control and enhanced oil recovery.

New Aqueous Solutions with Lower Viscosities than Water

Abstract Liquid water exhibits many anomalous physical properties because of its unique structure and hydrogen bonding networks, which were mostly uncovered at the beginning of the 20th century. Because of its interesting properties and microstructures under various conditions and in aqueous solutions, understanding the behavior of water is important, but remains scientifically challenging. Regarding the viscosity of aqueous solutions, despite the discovery 147 years ago that very small amounts of certain salts decrease the viscosity of water slightly, there has been no significant progress to date. Herein, we report new aqueous solutions, with low additive fractions and much lower viscosities than pure water, which exhibit unique viscosity–composition curves. The findings should spark renewed interest in scientific research on water, which may greatly impact numerous industries.

Viscosity of aqueous solutions of mono-, di- and polysaccharides

It was found that the nature of the effect of mono- and disaccharides on the viscosity of aqueous solutions increases with increasing concentration. Solutions of a substance with a higher molecular weight (sucrose) have a higher viscosity than monosaccharides (glucose, fructose). Solutions of pectin in the studied concentration range (0.05 - 0.5% (wt)) have a viscosity in the range (1 - 1.5) 10-3 Pa∙s and behave like Newtonian fluids. The increase in viscosity in solutions of monosaccharide + pectin indicates a low intensity of the associative interaction of molecules in solution. It was found that the introduction of aqueous solutions of monosaccharides background concentration of pectin (C = 0.05%) can significantly bring the viscosity of monosaccharide solutions to the viscosity of disaccharide (sucrose). The composition of the complex additive monosaccharides + polysaccharide is proposed. The recommended concentration of pectin is 0.05 - 0.1%; monosaccharides 10 - 40%. The use of a complex additive (monosaccharides + polysaccharide) will provide the necessary stability of food semi-finished products.

Acoustical Parameters of Polyvinyl Alcohol

Ultrasonic investigation provides a wealth of information in understanding the intermolecular interaction of solute and solvent. An attempt has been made to measure density, viscosity and ultrasonic velocity of aqueous solution of polyvinyl alcohol of molecular weight approximately 140,000 at different temperatures 35οC, 40oC, 45οC, 50oC, 55οC, 60oC, 65οC at 0.8% concentration. Ultrasonic velocity is measured using ultrasonic interferometer at 1 MHz frequency. The acoustical parameters like, adiabatic compressibility, acoustic impedance, intermolecular free length and relaxation time have been calculated at different temperatures. These parameters were used to understand the behaviour of solute and solvent.

Volumetric and viscometric studies of molecular interactions in systems containing tartaric acid in water/aqueous-L-arginine solutions at 303.15 K

The densities and viscosities of aqueous solutions containing tartaric acid and L-Arginine were measured at 303.15 K. The densities were used to calculate the apparent molar volume of tartaric acid in water and aqueous-L-Arginine solutions. The apparent molar volumes were fitted to the linear fit Masson relation and relative viscosities were fitted to the Jones-Dole equation. From Masson relation, the partial molar volumes were determined and from Jones-Dole equation, the viscosity B-coefficients were determined. Strong solute-solvent interactions in aqueous solutions of tartaric acid solutions were observed from the transfer volumes and viscosity B-coefficient. The pH of these systems was also measured to understand the transfer of a proton from solute to cosolute. A weakening of solute-solvent interactions and loosening of the hydration sphere of tartaric acid on the addition of cosolute has been observed.