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The enthalpies of dissolution, ΔsolHm∞, and solvation, ΔsolvHm∞, of ether oligomers CH3O(CH2CH2O)nCH3(n= 1–4) in ethyl acetate, pyridine, N,N-dimethylformamide, and acetonitrile have been determined from calorimetric measurements at 298.15 K. The values of group contributions of repeated ether units and monoether fragment have been compared on the basis of the additive method. The contributions of ether group to ΔsolvHm∞for oligomeric and monomeric molecules coincide within their uncertainties for solutions in highly polar solvents, in contrast to non-polar, moderately polar, and H-bonding solvents. The dependence of ether group contributions to ΔsolvHm∞on the electron pair acceptance index of solvents ETNhas been considered.

Thermal stability of polyvinyl alcohol/cellulose nanocrystals composites has been studied. It has been shown that nanocrystalline cellulose in its acid form considerably enhances the thermal stability of the composites, while the neutral form of the nanocrystalline cellulose has little effect on the thermal stability of the composites.

Densities (ρ) and refractive indices ( nD) of glycine (Gly), DL-alanine (Ala), DL-valine (Val) (0.02, 0.04, 0.06, 0.08, and 0.10 mol·L −1) in 0.005 and 0.008 mol·L −1aqueous cetyltrimethylammonium bromide (CTAB) have been measured at 298.15, 303.15, 308.15, and 313.15 K. The density data have been utilized to calculate apparent molar volumes (ϕ v), partial molar volumes (ϕ v0), at infinite dilution and partial molar volumes of transfer ϕ v0(tr) of amino acids. The refractive index data have been used to calculate molar refractivity ( RD) of amino acids in aqueous cetyltrimethylammonium bromide. It has been observed that ϕ v0varies linearly with increasing number of carbon atoms in the alkyl chain of amino acids, and hence, was split to get contributions from the zwitterionic end groups (NH 3+, COO −) and methylene group (CH 2) of the amino acids. The behaviour of these parameters has been used to investigate the solute-solute, solute-solvent interactions and the effect of cetyltrimethylammonium cation on these interactions.

Measurements of density (ρ), viscosity (η), and refractive index ( n) were carried out on α-amino acids, DL-alanine (Ala), D-phenylalanine (Phe), and DL-threonine (Thr) (0.01-0.05 mol·L 1), in 0.05 mol·L −1aqueous caffeine solution at 298.15, 303.15, 308.15, and 313.15 K. These measurements have been carried out to evaluate some important parameters, viz., apparent molar volume (ϕ v), partial molar volume (ϕ 0v), transfer volume (ϕ 0v(tr)), viscosity Aand Bcoefficients of Jones-Dole equation, free energies of activation per mole of solvent (δμ 0#1) and solute (δμ 0#2), enthalpies (δ H*) and entropies (δ S*) of activation of viscous flow, variation of Bwith temperature (Δ B/Δ T)P, and molar refractive index ( RD). These parameters have been interpreted in terms of solute-solute and solute-solvent interactions and structure making/breaking ability of solutes in the given solution.

The thermal behaviour of some mixed-ligand complexes of Cu(I) and Ag(I) formed by the interaction of Cu(tu)3I and Ag(tu)I (where tu stands for thiourea) with py, 2-pic, 3-pic, 4-pic, qu, iqu, pip, ac, bpy and phen have been studied using TGA and DTA techniques. IR spectral and X-ray diffraction analyses have been employed to identify the nature of the dissociation products. The Cu (I) complexes lose thiourea in the first step and then the heterocyclic amine whereas in case of the Ag(I) complexes, the thiourea molecule leaves only after the removal of the heterocyclic amine from the complex. The thermal behaviour of the complexes shows that Cu (I) is more tenaciously bonded with nitrogen donors whereas Ag(I) has more affinity towards sulphur containing ligands.