Latent entropy at transition

Ignoring the temperature dependence of g, as justified by Jahnig (1979), the latent entropy AE for a repeat unit at the transition (Wang Warner, 1986) is 

It is known that the persistence length is normally about 2-10 times that of the repeat units for polymers, depending on the real structure of polymers. It is seen that the latent entropy is no longer a universal value, as in the Maier-Saupe theory. Some experimental results has been reviewed by Luckhurst (1986). 

The worm chain in a possible polar nematic phase was discussed as well (Wang Lam, 1992). The dipolar interaction was taken into account in addition to the quadrupolar interaction. It results in the complexity of the phase diagram. 

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It is illustrated that the N-I transition is of first order. Experimentally, the latent entropies of small molecular mass liquid crystals, AE(TC), are very diverse, ranging from 1.25 to 7.55 J/mol. K. Most fall in the range of 2.50-3.35 J/mol.K. The Maier-Saupe prediction for the latent entropy at transition is in reasonable agreement with experiments. 

Wang (1995a) calculated the N-I transition temperature, the critical order parameter and the latent entropy at transition according to the model... 

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