caa a22 4500 445327413 CHVBK 20180317142725.0 cr unu---uuuuu 170323e20110101xx s 000 0 eng 10.1007/s10953-010-9622-x doi (NATIONALLICENCE)springer-10.1007/s10953-010-9622-x Oweimreen G. Chemistry Department, King Fahd University of Petroleum and Minerals, 31261, Dhahran, Saudi Arabia aut Enthalpy-Entropy Compensation and Solubility Parameters for Solutions of Nonmesomorphic Solutes inthe Smectic-A, Nematic and Isotropic Phases oftheLiquid Crystal p - n -octyl- p ′-cyanobiphenyl [Elektronische Daten] [G. Oweimreen] Ratios of infinite dilution solute activity coefficients ($\gamma_{2}^{\infty} )$ for nonmesomorphic solutes at the smectic-A-to-nematic ($\gamma_{2,\mathrm{SA}}^{\infty}/\gamma_{2,\mathrm{N}}^{\infty} )$ and the nematic-to-isotropic ($\gamma_{2,\mathrm{N} '}^{\infty} /\gamma_{2,\mathrm{I}}^{\infty} )$ phase transition temperatures, $T_{\mathrm{S}\mbox{\scriptsize--}\mathrm{N}}$ and $T_{\mathrm{N} \mathrm{'}\mbox{\scriptsize--}\mathrm{I}}$ respectively, of p-n-octyl-p′-cyanobiphenyl (8CB) show that the solutes are more soluble in the isotropic phase than in the smectic-A and nematic phases where they exhibit a nearly equal solubility. The Flory-Huggins size effect correction ($\gamma_{\mathrm{F}\mbox{\scriptsize--}\mathrm{H}}^{\infty} )$, and the thermal ($\gamma_{\mathrm{T}}^{\infty} )$ and athermal ($\gamma_{\mathrm{I}\mbox{\scriptsize--}\mathrm{S}}^{\infty} )$ contributions to $\gamma_{2}^{\infty}$, are evaluated. Solute partial molar enthalpies (Δsolv H) and entropies (Δsolv S) of solvation show a compensation effect that reflects a delicate interplay between solute-solvent interactions and size and structure effects. Both the solute and solvent solubility parameters, δ 2 and δ 1 respectively, decrease as temperature increases. Additionally the δ 1 values undergo a discontinuous increase at $T_{\mathrm{S}\mbox{\scriptsize--}\mathrm{N}}$ attributed to the disappearance of the layered structure of the Smectic-A phase and a discontinuous decrease at $T_{\mathrm{N}'\mbox{\scriptsize--}\mathrm{I}}$ attributed to an increase in the flexibility of the alkyl tails of the liquid crystal molecules in the nematic phase. Evidence that hints at the effect of the structure of the liquid crystal solvent on the solution process is presented. Springer Science+Business Media, LLC, 2010 Enthalpy-entropy compensation nationallicence Liquid crystal solvents nationallicence Nonmesomorphic solutes nationallicence Solubility parameters nationallicence Journal of Solution Chemistry Springer US; http://www.springer-ny.com 40/1(2011-01-01), 79-92 0095-9782 40:1<79 2011 40 10953 https://doi.org/10.1007/s10953-010-9622-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10953-010-9622-x text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Oweimreen G. Chemistry Department, King Fahd University of Petroleum and Minerals, 31261, Dhahran, Saudi Arabia aut NATIONALLICENCE 773 0- Journal of Solution Chemistry Springer US; http://www.springer-ny.com 40/1(2011-01-01), 79-92 0095-9782 40:1<79 2011 40 10953 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer