Thermodynamic, FTIR, 1H-NMR, and acoustic studies of butylated hydroxyanisole and sodium dodecyl sulfate in ethanol, water rich and ethanol rich solutions

In this present work, we report the conductance, FTIR as well as H-1 NMR analysis for well known synthetic antioxidant; butylated hydroxyanisole (BHA) and anionic surfactant; sodium dodecyl sulfate (SDS). From the cmc and X-cmc values as a function of temperature, various thermodynamic parameters have been evaluated viz: (a) the standard enthalpy change (Delta H-m degrees), (b) standard entropy change (Delta S-m degrees), and (c) standard Gibbs energy change (Delta G(m)degrees). Utilizing the spectroscopic analysis, chemical shift/frequency was accounted in different conditions indicative of SDS molecule binding to BHA. Furthermore, the acoustic properties in three different compositions of ethanol containing water i.e. 100% (pure ethanol), 70% v/v (ethanol rich), and 30% v/v (water rich) solutions were also determined at three temperatures at an interval of 5 degrees C (25 degrees C, 30 degrees C, and 35 degrees C). Specifically, the density (rho), ultrasonic velocity (u) and viscosity (eta) as function of SDS containing BHA have been determined and the resulting data was used to estimate various acoustical parameters; the compressibility coefficient (beta), apparent molar volumes (phi(v)) and apparent molar compressibility (phi(k)). These calculated parameters were found to be sensitive toward the interactions prevailing in BHA-SDS-solvent system and interactions in different water-ethanol compositions. Convincingly existence of a good qualitative correlation is observed with regard to SDS-BHA interactions obtained from the measurements. (C) 2012 Elsevier B.V. All rights reserved.