氧化鋅奈米柱陣列長度與液晶預傾角關係之研究

Abstract

本論文旨在探討不同長度之氧化鋅奈米柱陣列對於液晶配向特性之研究，經由改變氧化鋅奈米柱陣列的長度來控制液晶分子的預傾角。氧化鋅奈米柱陣列是經由兩段式水熱法成長於ITO玻璃基板上，經由控制氧化鋅奈米柱的長度可以改變氧化鋅奈米柱陣列之表面型貌和折射率，並進而影響其親疏水性。實驗結果指出，不同長度的氧化鋅奈米柱陣列之折射率和水的接觸角與液晶預傾角有相當的關係。當奈米柱長度由65nm增加至230nm，折射率則由1.90下降至1.43，水的接觸角由93度降低至28度，預傾角約可從90度至0度之間連續地變化。實驗結果符合FCK rule和凡德瓦力配向理論。

Influence of ZnO nanorod length on the characteristics of the liquid crystal (LC) alignment was studied in this work. We found that the refractive index and surface wettability of the ZnO nanorod alignment films can be controlled by changing the length of the as-prepared ZnO nanorod arrays, fabricated by using the two-step hydrothermal method. The pretilt angle of LCs strongly depended on the refractive index and surface wettability of ZnO nanorod arrays, which can explained by van der Waals interaction and the semi-empirical Friedel-Creagh-Kmetz rule. The pretilt angle of the LCs was successfully adjusted over a range from 90° to 0° as the length of nanorod changed from 65nm to 230nm.