具電活性寡聚物改質之無機層材在高分子分散液晶中之光電性質探討及應用研究

Electro-optical Properties and Application of POA Intercataled Inorganic Layered Materials in Polymer-dispersed Liquid Crystals

李貞儒(Chen-Ju Lee)

指導教授 ： 蔡宗燕

中原大學/理學院/奈米科技碩士學位學程/碩士(2013年)

https://doi.org/10.6840/cycu201300994

摘要

本研究主要以無機奈米層材作為添加材，摻雜進入高分子分散液晶(Polymer-Dispersed Liquid Crystal, PDLC)薄膜系統中，對其液晶微滴之型態與光電特性的影響作探討。其中薄膜組成以向列型液晶E7、光敏感性高分子NOA65為主體，而摻雜之無機奈米層材分為兩類，一為人工層狀雙氫氧化物；另一為天然黏土層狀材料。兩者結構皆為多層片狀堆疊，層與層間以離子鍵結緊密結合。再以具有苯環結構之有機改質劑 (SAS) 以及苯環結構之電活性寡聚物 (POA) 分別對人工雙氫氧化物與天然黏土做有機改質。微量添加於PDLC中並外加適當電場量測其光電效應。實驗中利用廣角X光繞射光譜儀 (Wide Angle X-Ray Diffraction, XRD)、傅立葉轉換紅外線光譜儀 ( Fourier Transform Infrared, FTIR )及熱失重分析儀 ( Thermogravimetry Analyzer, TGA ) 對有機化改質之層狀材料作結構鑑定。將奈米層狀材料摻雜入PDLC之後再以電子掃描顯微鏡(Scanning Electron Microscope, SEM) 對其液晶滴型態的形成作探討，以XRD證明摻雜奈米層狀材料可增加液晶之結晶性且證明奈米層狀材料存在於液晶中，以穿透式電子顯微鏡(Transmission Electron Microscopy, TEM) 證實奈米層狀材料確實存在於高分子相中。接著，在外加交流電電場下量測閾值電壓、驅動電壓、對比度及瞬態時變之光學特性。以CL120/CL120-POA 0.9：0.1wt% 之特殊配比可降低閾值電壓約24.13% (10.9 Vrms到8.27 Vrms)、降低驅動電壓約55.96% (42.23 Vrms到18.6 Vrms)、提升對比度(Contrast Rate, CR) 約150.77% (9.73到24.4)、降低於25Vrms之反應(響應)時間 (Response Time, RT) 約87.94% (30.6ms到3.69ms)並改善因長時間光照射造成上升的驅動電壓。

關鍵字

高分子分散液晶 ； 層狀材料 ； 奈米複合材料 ； 電活性寡聚物

並列摘要

Inorganic nanoparticles are used as nanofillers into the polymer-dispersed liquid crystal (PDLC) film. The morphology of LC droplets in the hybridization PDLC film and electro-optical properties are studied in this work. The PDLC film is composed with nematic liquid crystal E7 and photosensitivity polymer norland optical adhesive (NOA65) as the polymer matrices. The inorganic nano-layerd materials can sort into two types, both of whose constructs are piled the layers between which the interaction are ionic bonded, one is the synthetic layered double hydroxides, and the other is a natural layered clay material. Then, the organic modifier (SAS) and the electroactive oligomer (POA) , contains benzene ring structure, perform as organic modification of double hydroxide for artificial and natural inorganic layered materials, respectively. The small amount of nanofillers are doped into the PDLC matrix and then those are measured the photoelectric effect through the appropriate electric field. Wide Angle X-Ray Diffraction (WXRD), Fourier Transform Infrared (FTIR), and Thermogravimetry Analyzer (TGA) are used to learn the characteristics of organically modified layered material. After doping the nano-layered materials into the PDLC matrix, the morphology of LC droplets is observed by Scanning Electron Microscope (SEM). It is proved that doped nano-layered materials can increase the crystallinity of liquid crystal and exist in liquid crystals by XRD and the nano-layered materials also exist in the polymer’s phase by using Transmission Electron Microscopy (TEM). Then it is measured threshold voltage, driving voltage, contrast rate, and optical properties of the voltage-transmittance and time-transmittance curves, which explain the charge-retention effect under the application of AC bias voltage. It is observed that the best formula is dopped of 0.9：0.1 wt% of CL120/CL120-POA in PDLC can effectively reduce 24.13 % (from 109 Vrms to 8.27 Vrms) of threshold voltage, 55.96 % (from 42.23 Vrms to 18.6 Vrms) of driving voltage, and 87.94 % (from 30.6ms to 3.69 ms on 25 Vrms) of response time; furthermore, improve 150.77 % (from 9.73 to 24.4) of contrast rate. Without the POA modified CL120, the rise of the driving voltage is apparently increased compared to the POA modified CL120 in PDLC matrix after a long-duration exposure.

並列關鍵字

nanocomposites ； Layered materials ； PDLC ； Electro-optical Properties

參考文獻

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