In this research, we explored the thermophysical characteristics of 3-ethyl-3-pentanol in combination with a selection of short-chain alcohols, specifically from C3 to C6 (1-propanol to 1-hexanol), over a range of temperatures from 293.15 K to 323.15 K. The exploration primarily focuses on examining both the excess molar volumes and viscosity deviations, revealing a consistent increase in negative excess molar volumes with the elongation of the alkyl chain. At the same time, an examination of viscosity presents deviations from expected ideals, displaying a positive pattern that lessens as the alkyl chain lengthens. This points to notable molecular interactions taking place among 3-ethyl-3-pentanol and the alcohols under study. Moreover, the study employed Free Volume Theory (FVT) to establish connections between the viscosities of both the individual substances and their combined mixtures. Notably, FVT closely matches our experimental data, with the largest difference seen being a 1.94% deviation in the mixture of 3-ethyl-3-pentanol and 1-pentanol. These results highlight the accuracy and relevance of FVT in providing insight into the viscosity of these mixtures, thereby deepening our understanding of their complex molecular dynamics.
