M.Sc.
http://hdl.handle.net/20.500.12228/45
2024-03-29T05:46:53ZVolumetric and Sound Velocity Studies on L-Lysine and L-Arginine in Aqueous Sodium Benzoate Solution at Different Temperature
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).
2018-09-01T00:00:00ZVolumetric and Viscometric Properties of N-Acetylcysteine in Dimethylformamide Containing Binary and Ternary Mixtures
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] [DMFH2O] 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] [DMFH2O]
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 solutesolvent interactions of the investigated systems. Sv, the
experimental slopes which provided an idea about the prevailing solutesolute
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 > NACH2O 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 > NACH2O,
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] [DMFH2O] solvent systems were found to be solute-solute interaction, where as
in NAC–DMF and NAC in [4:1] and [3:2] [DMFH2O] 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).
2019-06-29T00:00:00ZStudies on Volumetric and Viscometric Properties on N-Acetylcysteine in Acetic Acid-Water Binary and Ternary Mixtures
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
solutesolvent interactions while Sv is the experimental slopes which give an idea about
the prevailing solutesolute 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).
2019-06-29T00:00:00ZStudies on Volumetric and Sound Velocity of Ciprofloxacin in Aqueous Solution of Glucose, Sodium Chloride & Potassium Chloride Salts at Different Temperatures
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).
2018-06-01T00:00:00Z