Aslam Hossain

Solubility of DL-serine and DL-phenylalanine in aqueous mixtures of dimethyl sulfoxide and solvation thermodynamics

The standard free energies (ΔG0t(i)) and entropies (ΔS0t(i)) of transfer of DL-serine and DL-phenylalanine from water (1) to aqueous mixtures of dimethylsulfoxide (DMSO) (2) at 298.15 K are reported in the present study. The transfer energies have been determined from solubility measurements of the amino acids. The solubility is measured at different temperatures i.e. from 288.15 to 308.15 K by an ‘analytical gravimetric method’. The chemical parts of the free energies (ΔG0t,ch(i)) and entropies (TΔS0t,ch(i)) of transfer of the amino acids have been computed by subtracting the cavity effects and dipole–dipole interaction effects from the total transfer energies. The characteristics of the solvation thermodynamics of the amino acids in an aqua-organic solvent system are studied and discussed in the present manuscript.

Thermodynamics and mechanisms of glycine solvation in aqueous NaCl and KCl solutions at 298.15 K

In the present study the solubility of glycine in aqueous sodium chloride and potassium chloride solution was determined under different experimental conditions using ‘formol titrimetry’ method. The thermodynamic parameters like standard transfer Gibbs energies and entropies have been evaluated at 298.15 K. Other important parameters like molar volume, densities, solvent diameter, etc., of the experimental solutions have also been determined in this study. The above mentioned parameters have been used to determine ∆t,ch0(i)i.e., chemical effects of the transfer Gibbs energies and T∆t,ch0(i)i.e., chemical effects of the transfer entropy. The solvation of glycine is influenced by different factors such as nature of the solute, interactions between solute and solvents, etc., which has been explained by different physical and analytical approach.

Thermodynamics of DL-α-aminobutyric acid induced solvation mechanism in aqueous KCl solutions at 288.15–308.15 K

The solubilities of DL-α-aminobutyric acid in KCl solutions of different concentrations are measured at 288.15–308.15 K. Gibbs energies and entropies have been determined for transfer of α-aminobutyric acid form water to aqueous KCl solution at 298.15 K. The cavity, dipole-dipole and other interactions affecting the solubility, as well as stability of the amino acid in solution are also evaluated. Gibbs energy and entropy of transfer due to interactions are computed to create the model of the complex solute-solvent and solventsolvent interactions. Molar volume, densities, dipole moment of solvent and diameter of co-solvent in aqueous potassium chloride are also evaluated.

The Importance of Advance Biomaterials in Modern Technology: A Review

Nowadays development of biomaterials is a growing field of research which points to the introduction and application of some specific materials to substitute or supplement human tissues. The biomaterial technology plays a crucial role in providing cell environment. It is employed in treating millions of patients by means of various biological devices and prosthesis such as pace makers, artificial hip joints, hearing aids, etc. The goal of the present review is to assemble and interpret the important findings of current and prospective advance biomaterials and their applications in modern technology in an effort towards the advancement of regenerative strategies.