Eur. Phys. J. D (2021) 75: 296
https://doi.org/10.1140/epjd/s10053-021-00299-x

Regular Article – Molecular Physics and Chemical Physic

Study of molecular association in binary mixtures of poly(vinyl pyrrolidone) (PVP) with ethanol, 1-propanol and 1-butanol through thermo-acoustical, FT-IR, UV–Vis spectroscopy and DFT studies

¹ Condensed Matter Physics Lab, Department of Physics, University of Lucknow, 226007, Lucknow, U.P., India
² Quantum Simulation Group, Department of Physics, University of Lucknow, 226007, Lucknow, U.P., India

Received: 23 August 2021
Accepted: 25 October 2021
Published online: 25 November 2021

Abstract

In the present paper we report the variations of thermo-acoustical parameters along with FT-IR, UV–Vis analysis for the binary mixtures of PVP with ethanol, 1-propanol and 1-butanol with increasing concentrations. The thermo-acoustical parameters such as acoustic impedance (Z), surface tension ($\sigma$), relaxation time ($\tau$) and absorption coefficient ($\alpha /f^2)$ have been computed. The variation in these parameters manifest increased intermolecular interactions between PVP and polar solvents (ethanol, 1-propanol and 1-butanol) with concentrations. The intermolecular interaction is well corroborated and quantified by theoretical calculations based on density functional theory. The intermolecular hydrogen-bond strength has also been computed using the theory of Atoms in Molecules for higher concentration of these binary mixtures. FT-IR and UV–Vis spectra have been recorded at higher concentration range (0.7%, 0.8%, 0.9%) in the wavenumber range (4000–500 ${\text{cm}}^{-1})$ and wavelength range (200–400 nm) respectively. The experimental FT-IR and UV–Vis spectra are also in good agreement with the calculated data as obtained by the DFT/B3LYP method.