Partial local wetting

The first order wetting transition may occur if (-dfs/d< ))s does not change its sign when ( ) is varied. Then (-dfs/d< ))s may intersect the trajectory -2kV< )(< )) in a specific way depicted in Fig. 14b. Only two, out of four, intersection points — <]>ls and 2s - correspond to locally stable solutions of the variational problem. They describe two surface excess layers (see Fig. 14a) exhibiting partial (<]>1<( )ls t>2) and complete wetting (< )1<([)2 t>2s), respectively. The excess free energy Fe of these two composition profiles may be calculated with Eq. (27). Their energy differs by AFe presented in terms of the areas Sj and S2 in Fig. 14b ... 

Liquid crystals do not lend themselves to electron microscopy, as a liquid phase cannot be easily handled within a vacuum column unless cumbersome wet stages are employed. However, the fact that polymeric liquid crystals can be quenched to the glassy or partially crystalline states without any apparent disturbance of the local orientation characteristic of the liquid mesophase means that the electron microscope becomes a most useful tool. It is now providing new insights into the local molecular orientation in some liquid crystal polymer systems. 

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