Temperature-dependent thermoacoustic study of agarose in DMSO using 2 MHz ultrasonic wave propagation with FTIR spectroscopic correlations

The study reported here focuses on the foundational understanding of the molecular interaction of Agarose in DMSO using ultrasonic and spectroscopic methods. Ultrasonic velocity (U), density (ρ), and viscosity (η) were measured for different concentrations of Agarose at various temperature (293.15K, 298.15K, and 308.15K) using ultrasonic methods. The measured data were utilized to compute thermos-acoustical parameters such as adiabatic compressibility (β), intermolecular free length (L f ), acoustic impedance (Z), Relaxation time (τ), Free volume (V f ), ultrasonic attenuation (α/f 2 ), Gibb’s free energy (∆G), and Rao’s constant (R A ). These calculated parameters provide valuable information regarding solute-solvent interactions, and the role of hydrogen bonding and interacting forces in the system. The FTIR spectral analysis was studied to identify frequency shifts arising from interactions between agarose and the functional group present in the DMSO. FTIR analysis shows characteristic shifts in O−H and S=O vibrational bands, confirming the involvement of hydrogen bonding between agarose and DMSO molecules. The present study reveals that the agarose-DMSO system shows concentration and temperature dependent molecular behaviour, where increasing concentration enhances structural ordering, while hydrogen bonding and dipole-dipole interactions between agarose and DMSO govern the molecular organization of the system. The findings are significant for interpreting the physicochemical behaviour of agarose in organic solvents and may be useful in biochemical, pharmaceutical, and material science applications.