Volumetric, acoustic and viscometric properties of l-leucine and glycyl-l-leucine in aqueous solutions of isoniazid at different temperatures

Abstract

Amidst stupendously studies accomplished to unriddle the solute–solvent interactions, volumetric, acoustic and viscometric studies hold a consequential position. In the existing work, l-leucine and glycyl-l-leucine act as solute in aqueous isoniazid (solvent) in order to descry the solute–solvent interactions in the system at different temperatures and at atmospheric pressure. The experimental density has been employed in evaluating the volumetric parameters like apparent molar volume (Vϕ), limiting apparent molar volume (Voϕ), transfer parameters of volume (ΔtrV°ϕ) and limiting apparent molar expansibility (E°∅). The speed of sound has been applied in evaluating the compressibility parameters like apparent molar isentropic compression, limiting apparent molar isentropic compression (K°ϕ,s) and its transfer parameter (ΔtrK°ϕ,S). The transfer parameters deduct the interactions in the system on the behalf of co-sphere overlap model which shows dominating nature of the hydrophilic-hydrophilic interactions. Pair (VAB, KAB) and triplet (VABB, KABB) coefficient are also calculated. Using the viscosity data, the relative viscosity (ηr) and viscosity B-coefficient are calculated. The Hepler’s constant (∂E°∅/∂T) and first temperature derivative of B-coefficients (dB/dT) has been used to anatomize whether solute acts as structure maker or structure breaker in the solution.