http://hdl.handle.net/20.500.12228/45 Tue, 07 Apr 2026 03:21:50 GMT 2026-04-07T03:21:50Z http://hdl.handle.net/20.500.12228/906 Volumetric and Sound Velocity Studies on L-Lysine and L-Arginine in Aqueous Sodium Benzoate Solution at Different Temperature Mou, Iffat Ara In this study, a general volumetric and sound velocity method was used to analyze the effects of sodium benzoate (SB) on the structure of essential amino acids (L-lysine, L-arginine). Densities and sound velocities of L-lysine and L-arginine in aqueous and in aqueous 0.05 mol.kg-1, 0.2 mol.kg-1, 0.35 mol.kg-1 and 0.5 mol.kg-1 SB solutions have been studied at 293.15K to 313.15K with an interval of 5K. The density data have been used to calculate apparent molar volume (φv), limiting apparent molar volume (φv 0), limiting apparent molar volume transfer (Δtrφv 0), apparent molar expansibilities ( 0  E ) and Helper’s constant ( E / T) p 0    . The acoustic properties such as adiabatic compressibility (βs), apparent molar adiabatic compressibility (k), limiting apparent molar adiabatic compressibility (φk 0), apparent molar adiabatic compressibility transfer (Δtrφk 0), acoustic impedance (Z) and hydration number (nH) have been calculated by densities and sound velocities data. The densities increase with the increase of concentration of amino acids. Densities of amino acids in aqueous SB solutions are higher than that of amino acids in aqueous solution. The limiting apparent molar volumes (φv 0) and the values of experimental slope (Sv) are positive. The smaller values of Sv as compared to φv 0 values suggest the dominance of solute-solvent interaction over the solute-solute interaction. The limiting apparent molar volume transfer (Δtrφv 0) values of L-lysine and L-arginine in SB solutions are negative. This indicate that ion-hydrophobic and hydrophobichydrophobic group interaction are dominating over the hydrophilic-hydrophilic interaction. The values of limiting apparent molar expansion ( 0  E ) are positive. These trends in limiting apparent molar expansions for these amino acids in each concentration of SB solutions indicating the presence of solute-solvent interaction. The Hepler’s constant p ( E / T) 0    values of binary system are entirely positive for all studied amino acids suggest the studied systems act as structure makers. In ternary system some values are small negative and some values are positive. Hepler’s constant p ( E / T) 0    in ternary solutions indicating the structure making properties of amino acids in SB solutions. The values of partial molar volumes (V̅ 2) increase with increasing of concentration of L-lysine, L-arginine for the studied systems. As the concentration of amino acids increases, the adiabatic compressibility (βs) decreases. This indicates the water molecules around the amino acids are less compressible than the water molecules in the bulk solution. The negative apparent molar adiabatic compressibility (k) values indicate the greater loss of structural compressibility of water implying a greater ordering effect by the solute on the solvent. Δtrφk 0 values of L-lysine are positive whereas Δtrφk 0 of L-arginine are negative. This indicate that hydrophilichydrophilic and ion-hydrophilic interaction are dominating for L-lysine systems whereas hydrophobic-hydrophobic and ion-hydrophobic interactions are dominating for L-arginine systems. The small Sk values also indicates the solute-solvent interactions. The increase in acoustic impedance Z, indicates the presence of effective solvent-solvent interactions with the increase in solution concentration. The positive hydration number (nH) values indicate an admirable solubility of the solutes. Water molecules around amino acids have less shrinkage than water molecules in bulk solutions. The compressive strength of the ternary solution is less than that of the binary solution. This result suggests that the proteins or peptides generated from the studied amino acids will be denatured in ternary SB solutions. This thesis is submitted to the Department of Chemistry, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Science in Chemistry, September 2018.; Cataloged from PDF Version of Thesis.; Includes bibliographical references (pages 133-140). Sat, 01 Sep 2018 00:00:00 GMT http://hdl.handle.net/20.500.12228/906 2018-09-01T00:00:00Z http://hdl.handle.net/20.500.12228/762 Volumetric and Viscometric Properties of N-Acetylcysteine in Dimethylformamide Containing Binary and Ternary Mixtures Pal, Gopal The density and viscosity of NAC (0.10 to 1.00) mol.L−1 in H2O, DMF and DMF– H2O mixed solutions were measured and studied over the entire molarity range with in the temperature range of 298.15 to 318.15 K at 5 K interval. The apparent molar volumes, were determined from density values experimented by Density and Sound Velocity Meter (DSA 5000M) Anton Paar, Austria. In the NAC–H2O and NAC in [1:4] and [2:3] [DMFH2O] solvent systems the apparent molar volumes of NAC were found to be increased, whereas in the NAC–DMF and NAC in [4:1] and [3:2] [DMFH2O] solvent systems apparent molar volumes of NAC were found to be decreased. Apparent molar volume at infinite dilution, 0 v  and Sv values were also computed according to the experimented density values. The apparent molar volume at infinite dilution provided an idea about the presence of solutesolvent interactions of the investigated systems. Sv, the experimental slopes which provided an idea about the prevailing solutesolute interactions in the mixtures. Both 0 v  and Sv values indicated that there both solute-solute and solute-solvent interactions present in the binary as well as in ternary solutions. The investigated systems showed hasty increase of viscosity values with the increased NAC concentration but the values of viscosity decreased with the increase of temperature. In binary and ternary systems showed the similar trend viscosity changes but in different order of magnitude. The order for binary and ternary systems are: NAC– DMF > NACH2O and NAC in [3:2] [DMF–H2O] > NAC in [4:1] [DMF–H2O] > NAC in [2:3] [DMF–H2O] > NAC in [1:4] [DMF–H2O] > NAC–DMF > NACH2O, respectively. The viscosity values were employed to determine the viscosity coefficients i.e., A and B-coefficients; change of free energy, G*; change of enthalpy, H* as well as change of entropy, S*. Negative values of A and positive values of B co-efficients suggesting that weak solute-solute but strong solute-solvent interaction present in the binary and ternary solution, respectively. From these thermodynamic parameters state of the spontaneity of the investigated systems were known. On the basis of this data, the predominant molecular interactions occurring between NAC–H2O and NAC in [1:4] and [2:3] [DMFH2O] solvent systems were found to be solute-solute interaction, where as in NAC–DMF and NAC in [4:1] and [3:2] [DMFH2O] solvent systems solute-solvent interaction were predominant. This thesis is submitted to the Department of Chemistry, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Science in Chemistry, 29 June, 2019.; Cataloged from PDF Version of Thesis.; Includes bibliographical references (pages 74-80). Sat, 29 Jun 2019 00:00:00 GMT http://hdl.handle.net/20.500.12228/762 2019-06-29T00:00:00Z http://hdl.handle.net/20.500.12228/542 Studies on Volumetric and Viscometric Properties on N-Acetylcysteine in Acetic Acid-Water Binary and Ternary Mixtures Vattya, Banamali The density and viscosity of NAC (0.10 to 1.00) mol.L−1 in H2O, CH3COOH and H2O–CH3COOH mixed solutions were measured and analyzed over the whole concentration range at (298.15, 303.15, 308.15, 313.15 and 318.15) K temperatures. The apparent molar volumes were obtained from the experimental density data. In the NAC– H2O and NAC in [9:1] [H2O–CH3COOH] solvent systems the apparent molar volume of NAC increases, whereas in the NAC–CH3COOH and NAC in [4:1], [7:3] and [3:2] [H2O–CH3COOH] solvent systems it decreases. With the help of experimental density data apparent molar volume at infinite dilution, and Sv values were also calculated. The apparent molar volume at infinite dilution gives an idea about the presence of solutesolvent interactions while Sv is the experimental slopes which give an idea about the prevailing solutesolute interactions in the mixtures. The calculated data indicate that there may be solute-solute and solute-solvent interactions present in the binary and ternary solutions. Binary and ternary systems showed rapid increase of viscosity values with the increase in NAC concentration but the values of viscosity decreased with the increase of temperature for all the experimented system. The viscosity data were employed to find out the viscosity (A, B) coefficients, change of free energy, G*, change of enthalpy, H* as well as change of entropy, S*. From these thermodynamic parameters state of the spontaneity of the investigated systems were identified. Moreover, negative A and positive B co-efficient values suggesting that weak solutesolute but strong solute-solvent interaction present in the binary and ternary solution. On the basis of this data, the predominant molecular interactions occurring between NAC– H2O and NAC in [9:1] [H2O–CH3COOH] solvent systems were found to be solute-solute interaction, whereas in NAC–CH3COOH and NAC in [4:1], [7:3] and [3:2] [H2O– CH3COOH] solvent systems solute-solvent interaction were predominant. This thesis is submitted to the Department of Chemistry, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Science in Chemistry, June 2019.; Cataloged from PDF Version of Thesis.; Includes bibliographical references (pages 68-72). Sat, 29 Jun 2019 00:00:00 GMT http://hdl.handle.net/20.500.12228/542 2019-06-29T00:00:00Z http://hdl.handle.net/20.500.12228/524 Studies on Volumetric and Sound Velocity of Ciprofloxacin in Aqueous Solution of Glucose, Sodium Chloride & Potassium Chloride Salts at Different Temperatures Khanam, Masuda In this study, volumetric and sound velocity method was applied to analyze the interaction of ciprofloxacin on the structure of glucose, NaCl and KCl. Densities and sound velocities of glucose, NaCl and KCl in water and in aqueous ciprofloxacin (0.03, 0.045 and 0.06) mol.kg-1 solutions have been studied at 293.15 K to 318.15 K with an interval of 5 K temperature. The density values have been used to calculate apparent molar volume (φv), limiting apparent molar volume (φv 0), limiting apparent molar volume transfer (Δtrφv 0), apparent molar expansibilities (δφv 0/δT)p and Hepler constant (δ2φv 0/δT2)p. The acoustic properties such as adiabatic compressibility (βs), apparent molar adiabatic compressibility (φk), limiting apparent molar adiabatic compressibility (φk 0), apparent molar adiabatic compressibility of transfer (Δtrφk 0), acoustic impedance (Z), relative association (RA) and hydration number (nH) have also been calculated by densities and sound velocities data. The densities increase with the increase of concentration of glucose, NaCl and KCl. Densities of glucose, NaCl and KCl in aqueous ciprofloxacin solutions are higher than that of glucose, NaCl and KCl in aqueous solution. The increase of density with concentration of glucose, NaCl and KCl can be attributed to solute-solvent interaction. The limiting apparent molar volumes (φv 0) are positive at the studied temperatures for the all mixtures indicate the presence of solute-solvent interactions. The positive values of Sv indicate strong solute-solute interaction and φv 0 values suggest the dominance of solute-solvent interaction. The limiting apparent molar volume transfer (Δtrφv 0) values have been found negative for NaCl and KCl in (0.03 and 0.045) and (0.03, 0.045 and 0.06) mol.kg-1 aqueous ciprofloxacin solutions respectively, which suggest the existence of ion-hydrophobic and hydrophobichydrophobic group interaction. But Δtrφv 0 values are positive for glucose and NaCl in (0.03, 0.045 and 0.06) and 0.06 mol.kg-1 aqueous ciprofloxacin respectively, which suggest the existence of ion-hydrophilic and hydrophilic-hydrophilic interactions. The values of limiting apparent molar expansion (Eφ 0) are positive. The Hepler constant (δ2φv 0/δT2)p values are small negative for all studied glucose, NaCl and KCl suggest the studied systems act as structure makers. The values of partial molar volumes ( 2) increase with increasing concentration of glucose, NaCl and KCl for all studied systems. The sound velocity increases with the increase of concentration of glucose, NaCl and KCl. Sound velocities of glucose, NaCl and KCl in aqueous ciprofloxacin solutions are higher than those of glucose, NaCl and KCl in aqueous solution. This indicate that the increase of compactness of the medium with the increase in glucose, NaCl and KCl and ciprofloxacin concentration. The adiabatic compressibility (βs) decreases with the increasing concentration of glucose, NaCl and KCl. This indicates that water molecules around the glucose, NaCl and KCl are less compressible than the water molecules in the bulk solution. The negative apparent molar adiabatic compressibility (φk) values indicate the greater loss of structural compressibility of water. The values of limiting apparent molar adiabatic compressibility (φk 0) are negative. The values of apparent molar adiabatic compressibility transfer (Δtrφk 0) are mainly positive which suggest the existence of strong ion-solvent interaction. At lower concentration, negative values of Δtrφk 0 indicate that increase in hydrophobic-hydrophobic group interactions. The small Sk values also indicates the domination of solute-solvent interaction over solute-solute interaction. The acoustic impedance, Z increases with the increase of concentration of glucose, NaCl and KCl. The relative association, RA decreases linearly with increasing the concentration of solute indicates the increase of solute-solvent interaction. The positive hydration number (nH) values indicate an appreciable solvation of solutes. This thesis is submitted to the Department of Chemistry, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Science in Chemistry, June 2018.; Cataloged from PDF Version of Thesis.; Includes bibliographical references (pages 149-154). Fri, 01 Jun 2018 00:00:00 GMT http://hdl.handle.net/20.500.12228/524 2018-06-01T00:00:00Z