Tunable Surface Wettability of ZnO Nanoparticle Arrays for Controlling the Alignment of Liquid Crystals

Abstract

The control of the liquid crystal (LC) alignment is very important for both academic- research and practical applications. ix molecules aligned on the ZnO nanopattide arrays (ZnO NPAs) are demonstrated and the pretilt angles of LCs can be controlled by using ZnO NPAs with different surface wettability. The wettability of ZnO,NPAsiabticated by the solution-based hydrothermal method can be controlled by changing the annealingtemperatiire of the as-prepared ZnO NPAs. The measurements of the energy, dispersive,Spectra and photoluminesoence have shown that the chemical properties of ZnO NPAs have been changed with the annealing temperature. Our results show that the pretilt angle of LCs can be tuned continuously from similar to 0 to similar to 90 degrees as the contact angle of water on ZnO NPAs changes from 33 to 108 degrees.