![Sample our Physical Sciences journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/110819/TOC-Subject-Sample-2021-Physical-Sciences.jpg"})
Abstract
A complete theory of surface nematic anchoring was developed earlier, including steric, dielectric, flexoelectric, and notably, surface polarization coupling mechanisms. In the last three cases surface electric field due to the adsorption of surface charges on the substrates is of ultimate importance. The extent of penetration of surface electric field inside a nematic is shorter than believed, due to the important surface screening. This leads to a substantial dehancement of dielectric coupling.
Surface polarization, due to the biphilic character of the short-range interaction of asymmetric nematic mesogens with the substrates, can be parallel or antiparallel to the surface electric field. This amounts to a stabilization or a destabilization of the anchoring. Based on the general theory the nonmonotonic behavior of anchoring energy of 5CB on LB films of DPPC with variable surface density is rationalized.