Molecular Interaction of Polymer Dextran in Sodium Hydroxide through Evaluation of Thermo Acoustic Parameters

Aim: To find out the molecular interaction of solute dextran of different concentration with sodium hydroxide as a solvent. Materials: Dextran of molecular weight 70000 dalton and aqueous 1(N) Sodium hydroxide. Methods: To Measure the density by specific gravity bottle, Viscosity by Ostwald's viscometer and ultrasonic velocity through ultrasonic interferometer of the solution and to calculate the thermo acoustical parameters using the measured parameters. Results: Ultrasonic wave propagation affects the physical properties of the medium and hence furnishes information on the physics of liquid and solution. I have used the measured parameters, like ultrasonic velocity, density, viscosity and evaluated parameters to understand the solute-solute and solute-solvent interactions in the solution containing dextran with sodium hydroxide. Conclusion: The effect of frequency on thermo acoustical parameters had been studied. From the above studies, the nature of forces between molecules such as hydrogen bonds, charge transfer complexes, breaking of hydrogen bonds and complexes had been interpreted. Intermolecular forces (electrostatic forces between charged particles of a permanent dipole and an induced dipole molecules) are weak. Structural characteristics of the components arising from geometrical fitting of one molecules in to another due to the difference in shape and size of the molecules. In the present study ultrasonic velocity (U), viscosity () and density () have been measured at temperature 308 K in the solution of sodium hydroxide with polymer dextran in the concentration range 0.1% to 1 % at four different frequencies i.e. 1 MHz, 5 MHz, 9 MHz and 12 MHz using ultrasonic interferometer. The measured values of ultrasonic velocity (U), viscosity () and density () have been used to calculate the thermoacoustic parameters namely free volume (V f ), internal pressure (i), attenuation coefficient /absorption coefficient (), Rao's constant (R) and Wada's constant (W) etc, These acoustical parameters are highly essential in studying various types of molecular interactions in liquid solution and provide qualitative information regarding the physical nature and quality of the molecular interaction in binary mixture dextran 1(N) sodium hydroxide. The molecular interactions like electrostriction, acceptor-donor association, dipole-dipole association and hydrogen bonding have been analyzed based on these parameters. Molecular interactions provide an understanding of the fundamental problems concerned with the mechanism of chemical and biochemical catalysis and the paths of the chemical reaction.