Reliability study of polymer dispersed liquid crystal for smart window application

• Main Authors: Wei-Hung Lai, 賴威宏
• Other Authors: Tsung-Hsien Lin
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/svu4bd

碩士 === 國立中山大學 === 光電工程學系研究所 === 103 === “Active Energy-saving Smart Window” is an active system that has ability to adjust the radiation of sunlight. One of those technologies is “using polymer dispersed liquid crystal (PDLC) to fabricate an electrical driving system of smart window which can regulate outdoor light.” Such a technology has a great effect on privacy protection because the mechanism of the dark state could scatter the incident light. By controlling applied voltage, users can depend on their requirement to switch the transmittance of light from outsides. However, there is about 5% to 8% ultraviolet light in the sunlight. The ultraviolet light not only harms the skin of human beings, but also causes the organic polymer’s degradation such as yellowing, cracking, chalking…etc. In this work, we research the forming principle of PDLC at first and understand the electro-optical characteristics of PDLC in different parameters of manufacture. Next, to study the electro-optical characteristics of liquid crystal before and after UV irradiation such as refractive index anisotropic, threshold voltage, response time and optical transmittance. We surmise the influence of polymer’s degradation via compare the degradation of liquid crystal with PDLC. Then, we discuss the EO-characteristics of PDLC in different morphologies under the irradiation of UV light. At the end, we give a solution to improve the lifetime of PDLC in irradiation of UV light. Making use of doping UV absorber in PDLC, we study the parameters of manufacture and discuss the lifetime under the irradiation of UV light.