Journal of Chemical Physics, Vol.118, No.6, 2903-2910, 2003
Volume transition of nematic gels in nematogenic solvents
Equilibrium swelling and phase behavior of liquid crystalline (LC) networks swollen in miscible nematogenic solvents has been investigated by polarizing microscopy as a function of temperature. Four systems, i.e., each of two different LC networks comprising dissimilar mesogens in two different nematic solvents, exhibit essentially the same swelling and phase characteristics. The swelling characteristics strongly correlate with the phases of the LC molecules inside and outside the gel. The two independent nematic-isotropic transition temperatures for the gel (T-NI(G)) and the surrounding pure solvent (T-NI(S); T-NI(G)>T-NI(S) for all the systems examined) yield three characteristic temperature regions. In the totally isotropic and nematic phases (T>T-NI(G) and T