Chapter II. Review of Literature

Transcription

1 Chapter II Review of Literature

2 35 CHAPTER II REVIEW OF LITERATURE A literature review discusses published information in a particular subject area within a period of time. The reports help to keep the professionals to update with what is current in the field. The depth and breadth of the literature review emphasizes the credibility of the writers in their fields. Literature reviews also provide a solid background for a research paper s investigation. A deeper knowledge of thermodynamic and transport properties of systems consist of biologically important compounds in aqueous medium provides information about solute-solvent and solute-solute interactions that help us to understand several biochemical processes such as hydration, denaturation, aggregation, etc. It has been found out that salt solutions have large effects on the structure and the properties of biologically important compounds like proteins, carbohydrates, etc. Review of literature reveals the effects of cations and anions of natural salts on the solubility, stability and activities of biologically important compounds.

3 THERMODYNAMIC AND TRANSPORT PROPERTIES OF AMINO ACIDS Rohankar and Aswar 1 have studied apparent molar volume and apparent molar compressibility of glycine in aqueous vanadyl sulphate solutions at different temperatures and reported negative transfer of volume from water to 0.1 M and 0.05 M aqueous vanadyl sulphate solutions. The results were explained on the basis of electrostriction. Banipal and Gagendeep Singh 2 have evaluated partial molar adiabatic compressibilities and viscosities of glycine, DL-α-alanine, L-valine, L-leucine and L-phenylalanine in aqueous 1,4-dioxane solutions at K and have shown that the positive partial molar adiabatic compressibility of transfer and their magnitude increases with increase in concentration of 1,4-dioxane, B-coefficient values for the studied amino acids in 1,4-dioxane are higher than the corresponding values in water. Changwei Zhao et al 3 have reported partial molar volumes and viscosity B-coefficients of arginine in aqueous glucose, sucrose and L-ascorbic acid solutions at K. Partial molar volumes of transfer and viscosity B-coefficients of arginine increase with increasing the mass concentration of sugar or L-ascorbic acid, and the hydration number of arginine decreases owing to the interaction of sugar or L-ascorbic acid and the zwitterionic groups.

4 37 Amalendu and Suresh Kumar 4 have performed volumetric studies of L-valine and L-leucine in aqueous solutions of sodium bromide at K and interpreted the trends of transfer volumes in terms of solute-cosolute interactions on the basis of a cosphere overlap model. Ponnadurai Ramasami and Rita Kakkar 5 have investigated partial molar volumes and adiabatic compressibilities at infinite dilution of amino carboxylic acids and glycylglycine in water and aqueous solutions of sodium sulphate at different temperatures and the results were explained on the basis of scaled particle theory. Amalendu pal and Suresh Kumar 6 have performed volumetric and viscometric studies of glycine in binary aqueous solutions of sucrose at different temperatures and the results have been discussed in terms of solute-solute, solute-solvent interactions and the structural changes of the solutes in solutions. Zhenning et al 7 have studied apparent molar volumes and viscosity B-coefficients of some α-amino acids in aqueous solutions at three different temperatures and discussed the results on the basis of the contributions of (NH + 3, COO - ) and CH 2 groups. Hua Zhao 8 has studied viscosity B-coefficients, standard partial molar volumes, the effect of organic solutes and various ions on the

5 38 viscometric and volumetric properties of amino acids and interpreted the stabilization of proteins. Viscosities and apparent molar volumes of some amino acids in water and in 6M guanidine hydrochloride at 25 o C were studied by Bulent Belibagli and Erol Ayranci 9. Positive transfer properties were interpreted in terms of strong interactions of guanidine hydrochloride molecules with the charged centers of amino acid molecules. Zhenning Yan et al 10 have studied apparent molar volumes and viscosities of some α-amino acids in aqueous sodium butyrate solutions at K and reported the standard partial molar volumes. Standard volumes of transfer and the B-coefficient vary linearly with increasing number of carbon atoms in the alkyl chain of the amino acids. Biswajit Sinha et al 11 have made their studies on apparent molar volumes and viscosity B-coefficients of some amino acids in aqueous tetramethyl ammonium iodide solutions at K and discussed the results in terms of ion-dipolar, hydrophobic-hydrophobic, and hydrophilic-hydrophobic group interactions. Banipal et al 12 have investigated apparent molar volumes and viscosities of some amino acids in aqueous sodium acetate solutions at K. Ramesh wadi and Rmakant Goyal 13 have studied the effect of temperature on apparent molar volumes and viscosity B-coefficients of

6 39 amino acids in aqueous potassium thiocyanate solutions from 15 to 35 o C and discussed the results on the basis of hydrophilic and hydrophobic interactions between the various groups present in these solutions. Qingwang, Liu et al 14 have determined limiting partial molar volumes of glycine, L-alanine, L-serine in ethylene glycol + water mixtures at K and concluded that the presence of ethylene glycol in water decreases the extent of electrostriction caused by the amino acid. Apparent molar volumes of L-glycine, L-alanine and L-serine in water + dimethyl formamide mixtures at K were determined by Xiaoling Ren et al 15 and the results were interpreted in terms of the structure making or structure-breaking effects of amino acids in the mixtures. Anwar Ali et al 16 have studied volumetric, viscometric and refractive index behaviour of α-amino acids and their groups contribution in aqueous D-glucose solution at different temperatures and interpreted the thermodynamic parameters in terms of solute-solute, solute-solvent interactions, structure making/breaking ability of solutes in the given solution, and the results 0 φ v, B-coefficient and 0* µ 2 have been split into group contributions of the amino acids using their linear correlation with number of carbon atoms in the alkyl chain of the amino acids.

7 40 Banipal et al 17 have studied the effect of magnesium acetate on the volumetric and transport behaviour of some amino acids in aqueous solutions at K and interpreted the results in terms of the hydration of hydrophilic and hydrophobic parts of amino acids. Viscosities of glycine and DL-alanine in water + acetonitrile mixtures between 25 and 40 o C were studied by Nibaran Dey et al 18 who have found the viscosity B-coefficients increase with increase in concentration of acetonitrile and also with the increase of temperature in both cases. Amalendu Pal and Suresh Kumar 19 have reported viscometric and volumetric studies of some amino acids in binary aqueous solutions of urea at various temperatures and interpreted the results in the light of ionion and ion-solvent interactions and of structural effects of the solutes in solutions. Man Singh et al 20 have made their studies on density, apparent molar volume and viscosity of bovine serum albumin (BSA), egg albumin and Lysozyme in aqueous rubidium iodide (RbI) caesium iodide (CsI) and dodecyl trimethyl ammonium bromide (DTAB) and investigated that the density of proteins decreases with salt concentration and the order of the effect of additives on density is CsI > RbI > DTAB.

8 41 The trend of apparent molar volume of proteins is found as BSA > egg albumin > lysozyme for all three additives. Thermodynamic studies on the interactions of diglycine with magnesium chloride in aqueous medium at different temperatures were made by Bhajan Lark et al 21 who found the positive transfer functions which decrease with increase in temperature and increase with the concentration of magnesium chloride. Biswajit Sinha et al 22 have studied apparent molar volumes and viscosity B-coefficients of glycine in aqueous silver sulphate solutions at different temperatures and the results were discussed on the basis of solute-solute and solute-solvent interactions. Correlations of thermodynamic properties of aqueous amino acidelctrolyte mixtures were studied by Saritha et al 23. Ultrasonic studies of 4-aminobutyric acid in aqueous metformin hydrochloride solutions at different temperatures were made by Rajagopal et al 24 and the results are used to interpret the solute-solute and solute-solvent interactions of 4-aminobutyric acid in aqueous metformin hydrochloride solutions. Ultrasonic velocity (u), viscosity (η) and density (ρ) have been measured for three amino acids viz., glutamine, arginine, lysine in aqueous DMSO solutions at K by Palani et al 25. Using the

9 42 experimental values, the adiabatic compressibility, hydration number, apparent molar compresiblility apparent molar volume, limiting apparent molar compressibility, limiting apparent molar volume and their constants, transfer volume and viscosity A and B coefficients of Jones- Dole equation were calculated. The experimental results have been discussed in terms of ion-solvent and solute-co-solute interactions on the basis of cosphere over lap model. Densities, viscosities and refractive indexes of three amino acids (glycine, L-alanine, and L-valine) in aqueous solutions of an ionic liquid, 1-propyl-3-methylimidazolium bromide, were measured at K by Shekaari et al 26. These data were used to calculate apparent molar volumes, viscosity B-coefficients and molar refractions of these mixtures. The standard partial molar volumes and standard partial molar volumes of transfer were determined for these amino acid solutions from these density data. The resulting values of transfer of amino acids from water to aqueous ionic liquid solutions were interpreted in terms of solute + solvent interactions. These data also indicate that hydrophobic interactions predominate in L-alanine and L-valine solutions. Linear correlations were found for both and the viscosity B-coefficient with the number of carbon atoms in the alkyl chain of the amino acids, and were used to estimate the contribution of the charged end groups (NH + 3,COO - ),

10 43 the CH 2 group, and other alkyl chains of the amino acids. The viscosity and molar refractivity results were used to confirm the conclusions obtained from volumetric properties. Ultrasonic velocity (u), density (ρ) and viscosity (η) have been measured for three amino acids viz., asparagine, histidine and lysine in aqueous K 2 SO 4 solution (0.5 m) at K by Palani et al 27. Using the experimental values, the adiabatic compressibility, hydration number, apparent molar compressibility, apparent molar volume, limiting apparent molar compressibility, limiting apparent molar volume and their constants transfer volumes and viscosity B-coefficient of Jones-Dole equation were calculated. The results of the parameters have been discussed in terms of ion-ion and ion-solvent interactions. Density (ρ) and viscosity (η) were measured for glycine, DL-α-alanine DL-α-valine, and DL-α-leucine in 0.05, 0.10, 0.15 and 0.20 mol. L -1 aqueous metformin hydrochloride at , and K by Rajagopal, K. & Jayabalakrishnan, S.S 28. The measured values were used to estimate some important parameters, such as partial molal volume standard partial molal volume, transfer volume, hydration number, the second derivative of infinite dilution of partial molal volume with respect to temperature, viscosity B-coefficient, variation of B with

11 44 temperature, viz., db/dt, free energy of activation per mole of solvent and solute of the amino acids. These parameters are interpreted in terms of solute-solute and solute-solvent interactions and structure making / breaking ability of solutes in the given solution. In addition, 0 φ v, 0 φ v, viscosity B-coefficient, B and 0* µ 2 are split into group contributions (NH + 3 COO - ) and -CH 2 of the amino acids using their linear correlation and their behavior is discussed. The apparent molar volumes for glycine, L-alanine, phenylalanine, and glycylglycine in 0.10 m aqueous D-galactose solutions have been determined from density measurements at (298.15, , , and ) K by Ali et al 29. The data were utilized to estimate the partial molar volume at infinite dilution, and experimental slope. The transfer volume, and hydration number, (n H) were also evaluated. The viscosity data were used to evaluate A- and B-coefficients of the Jones-Dole equation, the free energy of activation of viscous flow per mole of the solvent and the solute. The molar refractivity was calculated from refractive index data. The results were discussed in terms of hydrophilicionic, hydrophilic - hydrophobic, and hydrophobic - hydrophobic interactions, and structure-making/-breaking ability of the solute in aqueous D-galactose solutions.

12 45 Density (ρ), viscosity (η) and ultrasonic velocity (u) have been measured for L-glutamine, L-asparagine and L-lysine in water and aqueous glycerin (0, 0.5 and 1 mol dm -3 ) at K by Palani, R. & Reeginal, Y 30. These measurements have been performed to evaluate some important parameters viz. adiabatic compressibility, molar hydration number, apparent molar compressibility, apparent molar volume, limiting apparent molar compressibility, limiting apparent molar volume and their constants (SK, SV), transfer volumes and viscosity A and B coefficients of Jones-Dole equation. The results have been discussed in terms of solute-co-solute and ion-solvent interaction. Apparent molar volumes, viscosities and apparent isentropic compressibilities, of glycine, L-alanine, L-valine and L-leucine in 0.05, 0.10, 0.15 mol kg -1 catechol solutions have been determined at K by measuring the densities, viscosities and ultrasonic speed of the above solutions respectively by Roy et al 31. The standard partial molar volumes, standard volumes of transfer, standard partial isentropic compressibilities, transfer compressibilities, hydration number, of the amino acids have been calculated for investigating the various interactions in the ternary solutions. The linear correlation of partial molar volume and viscosity B-coefficients with increasing number of carbon atoms in the alkyl chain

13 46 have been used to explain the contribution of charged end group (NH + 3, COO - ) and the -CH 2 group to the standard partial molar volume. The results have been interpreted in the light of solute-solvent interactions in the mixed ternary solutions. Ultrasonic velocity (u), viscosity (η) and density (ρ) have been measured for three amino acids viz., L-serine, L-proline, L-histidine in aqueous 1,4-dioxane mixtures (0.6m) at K by Palani et al 32. Using the experimental values, the adiabatic compressibility, molal hydration number, apparent molal compressibility, apparent molal volume, limiting apparent molal compressibility, limiting apparent molal volume, their constants, and viscosity coefficients of A and B parameters of Jones-Dole equation were calculated and the results of these parameters have been discussed in terms of solute-solvent and solute-cosolute interactions. Ultrasonic velocity (u), density (ρ) and viscosity (η) have been measured for three amino acids viz., L-serine, L-leucine and L-histidine in aqueous magnesium chloride solution at K by Palani et al 33. Using the experimental values, the adiabatic compressibility, hydration number, apparent molal compressibility, apparent molal volume, limiting apparent molal compressibility, limiting apparent molal volume, and their

14 47 constant, transfer volume and viscosity A and B coefficients of Jones- Dole equation were calculated for all the ternary systems. All these results have been interpreted in terms of solute-co-solute and ion-solvent interactions in the given solution. Ultrasonic velocity (u), density (ρ) and viscosity (η) measurements were carried out for three amino acids namely L-arginine, L-lysine and L-histidine in aqueous sodium butyrate solution as a function of composition at 303, 308 and 313 K by Thirumaran, S. & Kannappan, A.N 34. Using these experimental values, the acoustical parameters such as adiabatic compressibility, apparent molal compressibility, apparent molal volume, limiting apparent molal compressibility, limiting apparent molal volume and the constants and viscosity B-coefficients were calculated for all the systems. The results are interpreted in the light of structure-making or structure-breaking effects of these amino acids in the mixture. Density, speed of sound and viscosity measurements were made for L-alanine ( mol kg -1 ) in aqueous fructose, maltose and lactose solutions, ranging from pure water to 25 mass % of saccharides at , , and K by Pal et al 35. These measurements were used to evaluate some important parameters, viz., apparent molar volume,

15 48 limiting apparent molar volume, transfer volume, viscosity B-coefficients of Jones-Dole equation, transfer B-coefficients, apparent molar adiabatic compressibility, limiting apparent molar adiabatic compressibility and its transfer values at infinite dilution. The activation free energy in different saccharide solutions were calculated from B-coefficients and partial molar volume data. Hydration number and interaction coefficients were also calculated from these data. These parameters were discussed in terms of solute-solvent interactions. The densities (ρ), viscosities (η), and refractive indexes (nd) of (0.10, 0.15, 0.20, 0.25, and 0.30) m glycine, L-alanine, and L-valine were measured in 0.01 m aqueous tartrazine at , , , , , and K by Ali et al 36. The measured data were utilized to evaluate various useful parameters, viz., apparent molar volume, partial molar volume, partial molar isobaric expansibility, transfer volume, A and B - coefficients of viscosity, free energy of activation of viscous flow per mol of solvent and solute and molar refractivity. The linear variation of 0 φ v with the number of carbon atoms (nc) present in the alkyl chain of amino acids was also considered for the evaluation of the contribution of zwitterionic end groups (NH 3 +, COO - ) and methylene groups to 0 φ v. The

16 49 results were used to discuss ion-ion, ion-nonpolar and nonpolar-nonpolar interactions and the presence of structural hydration in the present systems. The ultrasonic velocity (u), density (ρ) and viscosity (η) measurements have been carried out for four amino acids namely L-alanine, L-leucine, L-valine and L-proline in aqueous sodium acetate solution as a function of composition at 303, 308 and 313 K by Thirumaran, S. & Sabu, K. Job 37. experimental data have been used to estimate the adiabatic compressibility, change in adiabatic compressibility, relative change in adiabatic compressibility, apparent molal compressibility, apparent molal volume, limiting apparent molal compressibility, limiting apparent molal volume and the constants, and viscosity B-coefficient. The results are discussed in terms of structuremaking or structure-breaking effects of amino acids in the mixture. Apparent molar volumes, viscosities and apparent molal isentropic compressibility of glycine, L-alanine, L-valine and L-leucine in 0.05, 0.10, 0.15 mol kg -1 resorcinol solutions have been determined at K by measuring the densities, viscosities and ultrasonic velocity of the above solutions respectively by Roy et al 38. The apparent molar volumes at infinite dilution, standard volumes of transfer, apparent molar

17 50 isentropic compressibilities, transfer compressibilities, hydration number, of the amino acids have been calculated for investigating the various interactions in the ternary solutions. The linear correlation of partial molar volume and viscosity B-coefficients with increasing number of carbon atoms in the alkyl chain have been utilized to calculate the contributions of charged end groups (NH + 3,COO - ), CH 2 groups and other alkyl chains of amino acids to 0 φ v. The results have been interpreted in terms of ion-ion, ion-polar, hydrophilic-hydrophilic and hydrophobichydrophobic group interactions in the mixed ternary solutions. Densities and viscosities have been measured for solutions of DL-α-valine or DL-α-leucine in aqueous sodium caproate solutions at K and K by Yan et al 39. On the basis of these data, the apparent molar volumes, standard partial molar volumes, standard volumes of transfer, hydration number, and viscosity B-coefficients of DL-α-valine and DL-α-leucine have been determined. Combined with the corresponding data of glycine, DL-α-alanine, and DL-α-amino-nbutyric acid reported recently, it has been shown that the standard partial molar volumes and the viscosity B-coefficients of the amino acids vary linearly with increasing number of carbon atoms in the alkyl chain of the amino acids. These properties have been split into contributions from the

18 51 zwitterionic end group (NH + 3, COO - ) and CH 2 groups of the amino acids by using linear relations. The volumetric data suggest that sodium caproate interacts strongly with the zwitterionic end group of the amino acids, and the electrolyte has a strong dehydration effect on the amino acids. Viscosity data have been discussed on the basis of structure effects of the amino acids and their groups in the solutions flow. Densities and viscosities for solutions of some α-amino acids in aqueous calcium chloride (3.0 mol kg -1 ) have been determined at , , and K by Yan et al 40. These data have been used to calculate apparent molar volumes and viscosity B-coefficients of the amino acids. The standard partial molar volumes and hydration numbers of the amino acids have been determined at different temperatures. Free energies of activation for viscous flow of the solutions were obtained by application of the transition-state theory to the B-coefficient data, and the corresponding activation enthalpy and entropy were also given. It has been shown that 0 φ v, B-coefficients and the free energies of activation vary linearly with increasing number of carbon atoms in the alkyl chain of the amino acids and they were split into contributions from the zwitterionic end group (NH + 3, COO - ) and the methylene groups of the amino acids. The volumetric data have been interpreted in terms of the

19 52 hydration of the hydrophobic and hydrophilic parts of the amino acids. From the viscosity data, structural effects of the amino acids in the solutions have been discussed. Densities, ρ, and viscosities, η, of glycine, DL-α-alanine, DL-α-amino-n-butyric acid, and L-leucine in 1.0, 2.0, 4.0, and 6.0 mol / kg-1 aqueous 1,2-propanediol solutions have been determined at K by Banipal et al 41. The partial molar volumes obtained from densities have been used to calculate the corresponding volumes of transfer at infinite dilution from water to different concentrations of aqueous 1,2-propanediol solutions for rationalizing various interactions. The Jones-Dole equation has been fitted to the viscosity data to calculate B-coefficients. Results show that in the case of glycine and DL-α-alanine the ion-dipolar interactions are dominating while hydrophobichydrophobic and hydrophilic - hydrophobic interactions are also showing their predominant role in other cases. The apparent molar volumes, apparent molar isentropic compressibilities and enthalpies of dilution of aqueous glycine, alanine, α-amino butyric acid, valine, and leucine have been determined in aqueous 1.0 and 2.0 mol.dm -3 sorbitol solutions at K by Jha et al 42.

20 53 These data have been used to calc. the infinite dilution standard partial molar volumes partial molar isentropic compressibilities and enthalpies of dilution of the amino acids in aqueous sorbitol, along with the standard partial molar quantities of transfer of the amino acids from water to aqueous sorbitol. The linear correlation of for this homologous series of amino acids has been utilized to calculate the contribution to of the charged end groups (NH + 3, COO - ), the CH 2 group, and other alkyl chains of the amino acids. The results for the standard partial molar volumes of transfer, compressibilites and enthalpies of dilution from water to aqueous sorbitol solutions have been correlated and interpreted in terms of ion-polar, ion-hydrophobic and hydrophobic-hydrophobic group interactions. A comparison of these thermodynamic properties of transfer suggest that an enhancement of the hydrophilic/polar group interactions is operating in ternary systems of amino acid, sorbitol and water. The apparent molar volumes of L-lysine monohydrochloride, L-histidine, and L-arginine in water and in aqueous of sodium acetate, potassium acetate and calcium acetate solutions have been determined at temperatures from ( to ) K from density measurements by Siddique et al 43. The partial molar volumes at infinite dilution obtained

21 54 from φ v data were used to calculate the transfer volume of amino acids in water and in the presence of the cosolutes at different temperatures. These parameters are discussed in terms of various interactions between the α-amino acids and organic salts in these solutions. The dehydration effect of sodium, potassium, and calcium acetates is also discussed. The volumetric properties of amino acids (DL-glycine, DL-alanine, DL-serine, L-aspartic acid, L-lysine, and L-leucine) in aqueous solution of nonionic surfactant hexadecyl poly[oxyethylene(25)] alc. (C16A25) were studied by Harutyunyan et al 44. The values of apparent molar volumes, partial molar volumes and volumes of transfer were calculated. The changes of volumes of transfer are discussed in terms of hydrophilichydrophobic interactions. Enthalpies of solution and densities of glycine, L-alanine and L-serine in aqueous solutions of Na 2 SO 4 were measured at K by Liu et al 45. Transfer enthalpies ( tr H) and transfer partial molar volumes 0 ( tr φ v ) of amino acids from water to aqueous solutions of Na 2 SO 4 were derived. The tr H of L-alanine are positive and the tr H of glycine and L-serine are negative. The transfer volumes of all three of the amino acids are positive. The relative order in the negative value of tr H of amino acids in the same concentration of Na 2 SO 4 is L-serine < glycine <

22 55 0 L-alanine, whereas the sequence of tr φ v is L-serine > glycine > L-alanine. The results are discussed in terms of the cosphere overlap model. Densities, ρ, viscosities, η, and refractive indexes, nd, of solutions of some amino acids (glycine, DL-alanine, DL-α-amino-n-butyric acid, L-valine and L-leucine) in the concentration range 0.02 to 0.10 m in 5% (vol./vol.) aqueous glycerol were determined at , , and K by Ali et al 46. These experimental data were used to calculate the apparent molar volumes, φ v, the infinite dilution apparent molar volumes, 0 φ v, the partial molar volumes of transfer, 0 φ v, of the amino acids from aqueous to aqueous glycerol solution, as well as the viscosity A and B coefficients of the Jones-Dole equation of the amino acids. The results were interpreted in the light of the solute-solvent and solute-solute interactions in the mixed solvents Thermodynamic and transport properties of carbohydrates Cveto Klofutar et al 47 have studied the thermodynamic functions of activations for viscous flow of some monosacharides in aqueous solutions and found that the molar thermodynamic activation parameters for viscous flow were linearly dependent on the solute mole fraction, which

23 56 means that the partial molar quantities of activation of the solutes are concentration independent. Parimal C. Dey et al 48 have reported apparent molar volume and viscosity studies of some carbohydrates in water and surf excel solutions. The carbohydrates showed structure making behaviour both in water and in water-surf excel solutions. When water-surf excel solutions and pure water solutions containing carbohydrate molecules are compared, the former were found to be more structured and the behaviour of these solutes was discussed in the light of solute-solvent interactions. Volumetric and viscosity properties of monosaccharides in aqueous amino acid solutions at K were studied and reported by Kelei Zhuo et al 49. The values of transfer volumes and viscosity B-coefficients are positive and increase with increasing amino acid contents and the interactions between saccharides and aminoacids were discussed in terms of the structural interaction model and the stereo structure of monosaccharide molecules. Parampaul Banipal et al 50 have studied the effect of ammonium salts on the volumetric and viscometric behaviour of D(+) glucose, D(-) fructose and sucrose in aqueous solutions at 25 o C and reported positive transfer volumes for the saccharides in the presence of ammonium bromide, both positive and negative transfer volumes in the presence of

24 57 tetraethylammonium and tetra-n-butylammonium bromides. The parameters obtained from the volumetric and viscometric studies were used to understand various mixing effects due to the interactions between saccharides and ammonium salts in aqueous solutions. Thermodynamic and transport properties of some disaccharides in aqueous ammonium sulphate solutions at various temperatures were studied by Parampaul et al 51 and the results have been utilized to rationalize the hydration behaviour of disaccharides. Mahendra Nath Roy et al 52 have investigated apparent molar volumes and viscosity B-coefficients of carbohydrates in aqueous cetrimonium bromide solutions at three different temperatures and the structure-making or breaking ability of carbohydrates has been discussed in terms of the sign of ( 0 2 v / T ) φ as well as B / T. P Samanta and Saharay 53 have performed volumetric and viscometric studies of glucose in binary aqueous solutions of urea at different temperatures and the results were used to establish the nature of solutesolute and solute-solvent interactions. Apparent molar volumes, isobaric expansion coefficients, isentropic compressibilities, H/D isotope effects for some aqueous carbohydrate solutions were determined and the results were discussed in terms of the specific hydration model 54.

25 58 Nadezhda L. Volkova and Elena V. Parfenyak 55 have studied selective interactions of 18-crown-6 with D-glucose and D-galactose in aqueous solutions and reported that the crown ether forms a thermodynamically stable 1:1 complex with D-galactose but not with D-glucose. Ana C.F. Ribeiro et al 56 have determined binary mutual diffusion coefficients of aqueous solutions of sucrose, lactose, glucose and fructose in the temperature range from to K and the measured values were used with the Hartley equation to estimate activity coefficients for aqueous lactose, sucrose, glucose and fructose. Parampaul Kaul Banipal et al 57 have studied the effect of Sodium Sulphate on the volumetric, rheological and refractometric properties of some disauharides [D(+) cellobiose, D(+) lactose monohydrate, D(+) maltose monohydrate and sucrose] in aqueous solutions at 0 different temperatures, and the signs and magnitude of t V and 2 t B parameters have been discussed in terms of various interactions occurring in these solutions. D(+) cellobiose has shown characteristically different hydration behaviour among the studied disaccharides. Jan P. Amend and Andrey V. Plyasunov 58 have calculated the standard molal thermodynamic properties of aqueous pentoses and

26 59 hexoses at elevated temperatures and pressures. Reena Gupta and Mukhtar Singh 58 have made viscometric and thermodynamic studies of interactions in ternary solutions containing sucrose and aqueous alkali metal halides at three different temperatures and the structure-making and structure-breaking capacities of alkali metal halides in pure aqueous solutions and in the presence of sucrose have been ascertained from temperature dependence of 0 φ v. Rehana Saeed et al 59 have done volumetric studies of sodium chloride in aqueous and aqueous maltose systems at different temperatures and the data obtained from volumetric studies have been used to investigate the ion-solvent interaction and ion-ion interaction. The structure-breaking capacity of sodium chloride has been inferred in aqueous and aqueous maltose systems from the second derivative of partial molar volume with respect to temperature at constant pressure. Interaction between some monosaccharides and aspartic acid in dilute aqueous solutions was studied by Galina A. Kulikova and Elena V. Parfenyuk 60. It has been found that D-glucose and D-fructose form thermodynamically stable associates with aspartic acid, in contrast to D-galactose and the selectivity in the interaction of aspartic acid with monosaccharides is affected by their stereochemicl structures.

27 60 Parampaul K. Banipal et al 61 have studied the effect of sodium acetate on the volumetric behaviour of some mono-, di- and trisaccharides in aqueous solutions over temperature range ( to K) and reported positive transfer volumes for most of the saccharides, whose magnitude increases with the concentration of sodium acetate as well as temperature and negative values were observed for L(-) Sorbose, D(-) fructose and D(+) xylose at lower concentrations of co-solute. The negative magnitude of transfer volume values decrease with rise of temperature from to K. Parameters calculated have been utilized to understand various mixing effects in aqueous solutions due to the interactions between saccharide and sodium acetate. A study of the solution properties of selected binary mixtures of bulk and intense sweeteners in relation to their psychophysical characteristics has been done by Sneha A. Parke et al 62. Both specific volume and isentropic compressibility data have been used to interpret the possibility of synergism or suppression in the mixtures in terms of the affinity of the solutes for the surrounding solvent structure, and hence the effectiveness of transport of the molecules to their appropriate receptor sites. The intense sweeteners seem to play an important role in modifying the structure of water in solution. The study supports the idea that receptors lie at different depths in the lingual epithelium, and also that in

28 61 two-component systems, one species may alter the packing efficiency of the other in solution sufficiently to effect a change in taste quality or intensity. Maciej Starzak and Mohamed Mathlouthi 63 have studied the temperature dependence of water activity in aqueous solutions of sucrose and reported the isotherms of water activity coefficient exhibit a characteristic minimum at about 96% weight of sucrose which is then followed by a dramatic increase to values well exceeding 1. The effect of temperature on water activity, almost negligible for dilute solutions, was found significant for very concentrated solutions. Parmar et al 64 have evaluated partial molar volumes and their temperature derivatives for sucrose and urea in aqueous dimethyl 0 sulphoxide mixtures. The limiting apparent molar volumes ( v ) φ and the experimental slopes (S v ) have been interpreted in terms of ion-solvent and ion-ion interactions. The 0 φ v values vary with temperature as a power series of temperature. Both the solutes behave as structure-makers / promotors in the present system. Banipal, P.K. et al 65 have evaluated partial molar volumes of transfer of some saccharides from water to aqueous cupric chloride and

29 62 zinc chloride solutions at K, reported positive transfer volumes for all the saccharides studies and the value increase with increase in concentration of cosolutes. The results have been rationalized in terms of solute-cosolute interactions using a cosphere overlap hydration model. Ultrasonic velocity (u), viscosity (η) and density (ρ) of lactose of (0.5m) in three aqueous electrolytic solutions of guanidine hydrochloride (GuHCl), barium chloride (BaCl 2 ) and strontium chloride (SrCl 2 ) have been measured at K by Palani et al 66. The derived acoustical parameters namely adiabatic compressibility, apparent molal compressibility, apparent molal volume, limiting apparent molal compressibility, limiting apparent molal volume, and their constants, viscosity B-coefficient and hydration number have been computed from the experimental data. The variation of these parameters with respect to the molality of solute has been discussed in terms of solute-solvent and solute-co-solute interactions. The densities and viscosities of glucose solutions in water and in 0.05, 0.1, 0.5, 1.00 M NaCl, NaBr, KCl, and KBr were measured at , , , and K by Nikam et al 67. From densities (ρ), the limiting partial molar volumes were evaluated. The viscosity data were analyzed with the help of the modified Jones-Dole equation and the corresponding viscosity B-coefficients were calculated.

30 63 Apparent molar volumes and viscosity B-coefficients for D-(+)- glucose, D-(+)-galactose, D-(+)-xylose, and D-(-)-ribose in aqueous amino acid (glycine or L-alanine) solutions have been determined respectively from density and viscosity measurements at K by Zhuo et al 68. Infinite-dilution apparent molar volumes for the saccharides in aqueous glycine or L-alanine solutions have been evaluated, together with the standard transfer volumes of the saccharides from water to aqueous amino acid solutions. It is shown that values of transfer volumes and viscosity B-coefficients are positive and increase with increasing amino acid contents. Volumetric parameters indicating the interactions of saccharides with amino acids in water have been obtained from the transfer volumes of the saccharides. The interactions between saccharides and amino acids are discussed in terms of the structural interaction model and the stereo structure of monosaccharide molecules. Apparent molar volume and viscosity of fructose, glucose, mannose, and sucrose have been measured in dil. aqueous solution, concentration range M at 293 K by Mathpal et al 69. The viscosity coefficient B and A were calculated from the viscosity data using the Jones-Dole equation for all the studied sugars. The structure making behavior was obtained for all the sugars. A modified Jone-Dole equation was proposed by using ratio of mole fractions of solute and solvent in place of concentrations of solute.

31 64 Densities and viscosities of glucose and fructose solutions in water and in aqueous 0.5 mol dm -3 NH 4 Cl have been measured at , , and K by Nikam et al 70. From density data, apparent molar volumes at infinite dilution and from viscosity data, the B-coefficients are calculated. Glucose and fructose are found to be structure promoters in water as well as in aqueous 0.5 mol dm -3 NH 4 Cl solutions. Infinite-dilution standard partial molar volumes for various mono-, di-, and trisaccharides, and their derivatives (Me glycosides) at molalities ranging from 0.04 to 0.12 mol kg -1 in aqueous solutions of magnesium chloride of 0.5, 1.0, 2.0, and 3.0 mol kg -1, have been evaluated over a range of temperatures from to K by density measurements employing a vibrating-tube densimeter by Banipal et al 71. These data have been utilized to determine the corresponding standard partial molar volumes of transfer of saccharides and Me glycosides from water to aqueous magnesium chloride solutions. The various parameters have been discussed in terms of the solute (saccharide or Me glycoside)-cosolute (magnesium chloride) interactions and are thus used to understand the mixing effects due to these interactions. These results have been compared with those earlier reported in the presence of electrolytes. An attempt is made to interpret the volumetric properties data in terms of the stereochemistry of the solutes.

32 Transport properties of urea and its compounds Patric et al 72 have reported apparent molal volumes and heat capacities of urea and methyl substituted ureas in water and deuterated water at 25 o C. From these data urea-water interactions seem to cause an overall structure-breaking effect and the substituted ureas, an overall structure-making effect. The effect of the hydrogen bonding interactions to the volume and heat capacity seems to be small compared with the intrinsic and hydrophobic contributions of a methylene group, as reflected by the isotope effect. Transfer values seem to show a significant specificity to the degree and position of methyl substitution. Hironori Kokubo and Montgomery Pettitt 73 have analysed preferential salvation in urea solutions at different concentrations and showed that there were weak urea-urea and water-water associations. When urea molecules were divided into large, medium and small clusters to examine fluctuation properties and found that any particular urea molecule did not stay in the same cluster for a long time. Density and viscosity of aqueous urea solutions were determined as a function of concentration at 35, 40, 45, 50 and 55 o C, respectively by Motin et al 74. The apparent molal volume of urea was found to be linear function of solute concentration. From the φ v Vs. molality (m) plot the

33 66 apparent molal volume at infinite dilution, 0 φ v (taken to be equal to partial molal volume, 0 V 2 ) was determined. Viscosity coefficients B and D were calculated on the basis of the viscosity of the solutions and the solvent concerned using the Jones-Dole equation. The activation parameters for viscous flow were also calculated by means of the Eyring equation. The data were interpreted in terms of the structure making behavior of urea in water at o C temperature range Thermodynamic and volumetric properties of ascorbic acid M.N. Roy et al 75 have evaluated apparent molar volume, viscosity B-Coefficient, adiabatic compressibility of tetrabutylammonium bromide in aqueous ascorbic acid solutions at different termperatures and reported an increase in the transfer volume of tetrabutyl ammonium bromide with increasing ascorbic acid concentration has been explained by Friedman- Krishnan Co-sphere model. The activation parameters of viscous flow for the ternary solutions studied have also been calculated and explained by the application of transition state theory. Volumetric properties of ascorbic acid + polyethylene glycol + water systems at different temperatures were studied by Melike Sahin and Erol Ayranci 76 and the results were interpreted in terms of ascorbic acidwater-glycol interactions.

34 67 Zhao Changwel and Peisheng 77 have done the measurement and correltion on viscosity and apparent molar volume of ternary system for L-ascorbic acid in aqueous D-glucose and Sucrose solutions and the solute-solvent interactions in ternary systems of water-glucose-electrolyte and water-sucrose-electrolyte were discussed. Volumetric properties of ascorbic acid (Vitamin C) and thiamine hydrochloride (Vitamin B 1 ) in dilute hydrochloric acid and in aqueous sodium chloride solutions at six different temperatures were studied and reported by Guler Ayranci et al 78. Apparent molar volumes at infinite dilution for ascorbic acid and thiamine hydrochloride were found to increase with temperature in acidic solutions and in the presence of cosolute, sodium chloride. Apparent molar expansibility at infinite dilution were found to be constant over the temperature range studied and were all positive, indicating the hydrophilic character of the two vitamins studied in water and in the presence of co-solute, sodium chloride. Apparent molar isentropic compressibilities of ascorbic acid at infinite dilution were positive in water and in the presence of co-solute sodium chloride, at low molalities. Those of thiamine hydrochloride at infinite dilution were all negative, consistent with its ionic nature. Transfer molar volumes of vitamins at infinite dilution from water solutions to sodium chloride solutions at various temperatures were determined and the results were interpreted in terms of complex vitamin-water-co-solute interactions.

35 Thermodynamic and transport properties of carboxylic acids Maria Castaldi et al 79 have measured mutual diffusion and intradiffusion coefficients for the binary system L (+) tartaric acid + water at 25 o C. The collected diffusion coefficients have been combined with osmotic coefficients present in the literature to calculate the velocity correlation coefficients and the results are interpreted in terms of molecular interactions. The vapor-liquid equilibria, density, speed of sound and viscosity of aqueous dipotassium tartrate solutions at different temperatures have been measured by Mohammed Taghi Zafarani Moattar and Behnaz Asadzadeh 80. The experimental density and speed of sound data for dipotassium tartrate were used to obtain apparent molar volume and apparent molar compressibility values at different temperatures and these data were satisfactorily fitted to the corresponding Pitzer equations. The limiting apparent molar volume and limiting apparent molar compressibility at each temperature were obtained from the Redlich - Mayer and an abbreviated Pitzer model. The viscosity data were fitted to an empirical equation. Alexander Apelblat 81 has determined the dissociation constants of organic acids in aqueous solutions by the conductometric method and the experimental conductances were analyzed in terms of dissociation steps

36 69 of carboxylic acids and the onsager conductivity equation for neutral sodium or potassium salts. Mahendra Nath Roy et al 82 have investigated apparent molar volumes, viscosity B-coefficients for nicotinamide in aqueous citric acid monohydrate solutions from solution intensity and viscosity measurements at different temperatures as function of concentration of nicotinamide. The apparent molar volumes have been extrapolated to zero concentration to obtain the limiting values at infinite dilution using Masson equation. The structure making or breaking ability of nicotinamide has been discussed in terms of the sign of φ / T and v P B / T. An increase in the transfer volume of nicotinamide with increasing citric acid monohydrate concentration has been explained by Friedman - Krishnan Co-sphere model. The activation parameters of viscous flow for the ternary solutions studied have also been calculated and explained by the application of transition state theory. Adam Bald and Zdzislaw Kinart 83 have determined apparent molar volumes (φ v ) of two series of homologous aliphatic carboxylic acids and undissociated acids (φ v ). The variation of V 0 was determined as a function of the aliphatic chain length of the studied carboxylic acids.

37 70 Agnieszka Chmielewska et al 84 have measured viscosities and densities of aqueous solutions of sodium salts of monocarboxylic acids and dicarboxylic acids and the effect of hydrolysis of salts on viscometric data describing the objects under study was considered. The densities and viscosities of oxalic acid and its salts (ammonium oxalate, sodium oxalate and potassium oxalate) have been determined by Mahendra Nath Roy et al 85 and the obtained parameters have been interpreted in terms of ion-solvent and ion-ion interactions. Alexander Apelblat and Emanuel Manzurola 86 have measured densities and excess molar volumes of formic acid + water, acetic acid + water and propionic acid + water systems at three different temperatures. The results are satisfactorily described using the ideal association model of the type A + B + A 2 for the system with formic acid. The Mecke- Kempter model is adequate for the acetic acid + water and propionic acid + water systems. In both models the formation of open dimers and open higher associates is postulated for the self-association of carboxylic acids in water. Sauvage et al 87 have studied the dilute solution behaviour of several alternating copolymers of maleic acid by static and dynamic light scattering, intrinsic viscosity and pulsed-gradient spin-echo NMR

38 71 Spectroscopy. The copolymer of maleic acid-sodium salt and isobutylene dissolves readily in concentrated aqueous salt solutions. The hydrophobically modified copolymers of maleic acid-sodium salts and isobutylene show no sign of large intermolecular aggregation in 0.1N sodium acetate. The sizes of the copolymers are relatively small compared to that of the ionized parent copolymer, suggesting intramolecular aggregation of the alkyl side-chain groups along the polymer backbone. The copolymer modified with the longer chain n-decyl and stable large intermolecular aggregates containing 33 chains. A study on viscosities of citric cid and tartaric acid in water and binary aqueous mixtures of ethanol at different temperatures was made by M.L. Parmar et al 88. The data have been evaluated using Jones-Dole equation and the obtained parameters have been interpreted in terms of solute-solute and solute-solvent interactions. The activation parameters of viscous flow have been obtained which depicts the mechanism of viscous flow. Both the organic acids behave as structure breakers in water and in binary aqueous mixtures of ethanol. The densities and viscosities of oxalic acid and its salts, viz. ammonium oxalate, sodium oxalate, and potassium oxalate, were determined in w1 = (0.05, 0.10, and 0.15) mass fraction of 1,3-dioxolane + water mixtures at T = (298.15, , and ) K and p = 0.1 MPa

39 72 by Roy et al 89. Apparent molar volumes, viscosity B-coefficients of these electrolytes were obtained from their densities, viscosities. The limiting apparent molar volumes and experimental slopes derived from the Masson equation and the obtained parameters were interpreted in terms of ion-solvent and ion-ion interactions, respectively. The viscosity data were evaluated by the Jones-Dole equation. The structure-making/-breaking capacities of the electrolytes were inferred. The activation parameters of viscous flow for the ternary solutions studied were also calculated and explained by the application of transition state theory. Viscosity and density data for the ternary solution of hexanedioic acid + polyvinylpyrrolidone (PVP) + water at temperatures , , and K have been measured by Bai et al 90. On the basis of the Eyring and Feakins equation, the viscosity B-coefficients and the activation parameters for viscous flow of the solution have been evaluated. The effect of temperatures and PVP concentration on these parameters has been discussed. With the increase in PVP concentration, the activation free energy of diffusion for hexanedioic acid is decreased. This is an indication that the diffusion ability of hexanedioic acid is improved by the addition of PVP into solution. Apparent molar volumes of malonic and succinic acids have been determined in water and in aqueous solutions of mono- and disaccharides