Sk. Md Nayeem

Ultrasonic Investigations of Molecular Interaction in Binary Mixtures of Cyclohexanone with Isomers of Butanol

Ultrasonic speed, , and density, , have been measured in binary liquid mixtures of cyclohexanone with the isomers of butanol (-butanol, sec-butanol, and tert-butanol) at 308.15 K over the entire range of composition. Molar volume (), adiabatic compressibility (), intermolecular free length (), acoustic impedance (), and their excess/deviation along with have been calculated from the experimental data. These values have been fitted to Redlich-Kister type polynomial equation. Positive values of , , and negative values of , have been observed for all the liquid mixtures indicating the existence of weak interactions between components. Rupture of H-bond or reduction in H-bond strength of isomers of butanol or breaking of the structure of one or both of the components in a solution causes the existence of dispersions in the present investigated binary mixtures. The data obtained from , , and excess partial molar volumes , , reflects the inferences drawn from . Furthermore, FTIR spectra support the conclusions drawn from excess/deviation properties. The measured values of ultrasonic speed for all the investigated mixtures have been compared with the theoretically estimated values using empirical relations such as, Nomoto, Van Dael and Vangeels, Impedance and Rao specific sound speed.

Molecular interaction studies in the binary mixture of 1-ethyl-3-methylimidazolium trifluoromethanesulphonate+1-butanol from density, speed of sound and refractive index measurements

ABSTRACT A molecular interaction study was carried out between the ionic liquid 1-ethyl-3-methylimidazolium trifluoromethanesulphonate and 1-butanol using the experimental values of density, speed of sound and refractive index measurements over the whole composition range as a function of temperature between 298.15 and 328.15 K at atmospheric pressure. The excess/deviation properties such as molar volumes (), partial molar volumes (), partial molar volumes at infinite dilution (), isentropic compressibility (), free length (), speeds of sound (), refractive index () and isobaric thermal expansion coefficient () obtained from the experimental data were fitted into the Redlich–Kister type equation to obtain the binary coefficients and the standard deviations. The excess values clearly indicated the existence of strong molecular interactions between the studied components. A quantitative analysis of these parameters was further supported by IR spectroscopic analysis. In addition, analysis of data of the mixture was done through the Prigogine–Flory–Patterson theory.

Biomass nanofibrillar cellulose in nanocomposites

Abstract Macro- and nanocellulose fibers have attracted research attention due to their remarkable properties like biodegradability, high strength, and stiffness, as well as their synthesis and application for development of composites. Macro- and nanocellulose fibers can be employed as a reinforcement agent in composite materials due to their outstanding biodegradation, thermal, and mechanical properties. Due to the hydrophilic nature of cellulose fibers, it is essential to enhance their surface irregularity for the production of composites with improved properties. In this chapter, we have discussed the surface alteration of cellulose nanofibers by various processes. Different synthesis techniques, followed by ionic liquids, properties, categories, and different applications of nanocellulose and their composites, have been examined in this chapter.