摻雜硝基苯胺與聚方酸菁高分子於以PQ為光敏感劑之感光高分子材料在體積全像資訊儲存上之特性研究

Abstract

本論文主要的研究方向，主要在改善以Phenanthrenequinone (PQ)為光敏感劑的感光高分子材料在全像資訊儲存的特性表現，期望能研發出具有更佳全像記錄特性及反應性的材料。在本論文中首先將不同結構之硝基苯胺(nitroaniline)，如： N,N-dimethyl-4-nitroaniline (DMNA), N-methyl-4-nitroaniline (MNA)和 4-nitroaniline (pNA)，摻入PMMA/PQ的感光高分子中，並且利用波長為532nm之雷射，量測繞射效率(Diffraction efficiency)與動態儲存範圍(M#)等不同的光學實驗，探討所製備之材料在全像記錄上的特性。在結果中發現摻入硝基苯胺(nitroaniline)之感光高分子材料的繞射效率與動態儲存範圍皆有顯著的提升，其中以摻入DMNA之樣品的繞射效率可從38%提升至71%，而動態儲存範圍從2.7提升至7.3。為了瞭解摻入硝基苯胺之感光高分子的記錄機制，利用紫外光-可見光譜儀(UV-Vis)的吸收光譜、紅外線光譜儀(FTIR)、核磁共振光譜儀(NMR spectra)與X射線光電子能譜(XPS)等儀器分析。並從結果中發現了，DMNA在感光高分子照光記錄時並不會與PQ或殘餘的MMA單體產生光化學反應，其記錄機制是PQ與殘餘的MMA單體進行光化學反應時，因PQ的極化行為改變，而使DMNA的順向性產生了變化，而提升了感光高分子雙折射，使全像記錄的特性有顯著的改善。 第二部分主要是延續第一部分的研究成果，將DMNA與zinc methylacrylate (Zn(MA)2)同時摻入以PMMA/PQ的感光高分子中。利用Zn(MA)2會和DMNA分子反應，形成新的化合物，造成材料的雙折射有顯著的變化，而使全像記錄的特性有所提升。在514nm雷射的量測下，當同時摻入DMNA與Zn(MA)2時，其繞射效率會從原本PMMA/PQ的36.1%提升至86.2%。另外在動態儲存範圍的量測結果中發現，摻入DMNA與Zn(MA)2時M#也從原本的2.9提升至10.7。並利用質譜儀(Mass)與X射線光電子能譜(XPS)等儀器分析，分析感光高分子的記錄機制。 由第一部分和第二部分的結果發現，三級胺結構的硝基苯胺(para-Nitro-tertiary-anilines; (p-nitro-t-anilines))摻入PMMA/PQ感光高分子中，可改善感光高分子的雙折射，進而提升材料的全像記錄特性。因此，在第三部分選用了不同三級胺結構的硝基苯胺分子：N,N-dimethyl-4-nitroaniline (DMNA), N,N-Diethyl-4-nitroaniline (DENA), and N-Cyanomethyl-N-methyl-4-nitroaniline (CMMNA)摻入PMMA/PQ感光高分子中，針對全像記錄做一系列的研究。在研究中發現，摻入CMMNA分子的材料具有較高的雙折射，並且在繞射效率的量測中發現，摻有CMMNA分子的材料繞射效率會從原本的36.1%提升至81.9%。 最後，我們利用3-octylpyrrole和squaric acid合成了同時具有推電子基團(electron donor)與拉電子基團(electron acceptor)結構的聚芳酸菁(poly (3-octylpyrrole-co-squaric acid); PSQ3)分子，並嘗試將PSQ3分子導入PMMA/PQ感光高分子中，希望能改善材料的於全像儲存的特性。利用所製備的感光高分子薄膜進行了繞射效率(Diffraction efficiency)與動態儲存範圍(M#)的量測，在結果中發現，加入含有PSQ3分子的感光高分子的繞射效率可從9.0%提升至54.8% (提升約6.1倍)，而動態儲存範圍從0.46提升至1.05 (增加約2.2倍之多)，由此結果指出摻雜PSQ3分子對於全像特性的改善有其效果。

This study describes an approach toward improving the characteristics of a photopolymer for holographic data storage application. First of all, the diffraction efficiency (ηmax) and dynamic range (M#) of 9,10-phenanthrenequinone (PQ)–doped poly(methyl methacrylate) (PMMA) both improved significantly after co-doping with one of three nitroanilines—N,N-dimethyl-4-nitroaniline (DMNA), N-methyl-4-nitroaniline (MNA), and 4-nitroaniline (pNA). In particular, the value of ηmax increased from 38% for the PMMA/PQ system to 71% for the PMMA/PQ/DMNA system (a 1.89-fold improvement) and the value of M# increased accordingly from 2.7 to 7.3 (a 2.70-fold improvement). Thus, the holographic data storage characteristics of PMMA/PQ photopolymers can be improved through co-doping with nitroaniline compounds. We also investigated the mechanism of the nitroaniline-induced improvement in optical storage performance using proton nuclear magnetic resonance and X-ray photoelectron spectroscopy. In second part, through co-doping different compounds, N,N-dimethyl-4-nitroaniline (DMNA) and zinc methylacrylate (Zn(MA)2), into 9,10-phenanthrenequinone (PQ) doped poly(methyl methacrylate) (PMMA), the diffraction efficiency and the value of dynamic range (M#) have been progressed. We enhanced the diffraction efficiency (from 36.1 to 86.2%) and the dynamic range (M#, from 2.9 to 10.7) of 9,10-phenanthrenequinone (PQ)-doped poly(methyl methacrylate) (PMMA) through co-doping with N,N-dimethyl-4-nitroaniline (DMNA) and zinc methacrylate [Zn(MA)2]. Using mass spectrometry and X-ray photoelectron spectroscopy, we investigated the mechanism behind the improvements in optical storage induced by the presence of Zn(MA)2 and DMNA in PMMA/PQ. Next, three different para-Nitro-tertiary-anilines (p-nitro-t-anilines), N,N-dimethyl-4-nitroaniline (DMNA), N,N-Diethyl-4-nitroaniline (DENA), and N-Cyanomethyl-N-methyl-4-nitroaniline (CMMNA), co-doped with phenanthrenequinone (PQ) into poly (methyl methacrylate) (PMMA) significantly improved the holographic characteristics of the photopolymers to different degrees. These three co-dopants differed in their N-substituents only, which in turn changed the birefringence of the molecules. The samples with DMNA, DENA, and CMMNA increased their maximum diffraction efficiencies from 36.1 to 60.3, 69.6, and 81.9%, respectively. The CMMNA-doped sample demonstrated the best performance and highest birefringence in the recording process. The enhancement in maximum diffraction efficiency of the sample with CMMNA was up to 124%. The improvement in holographic recording characteristics paralleled the birefringence in the exposed photopolymers. Finally, we synthesized poly(3-octylpyrrole-co-squaric acid) (PSQ3), a polysquaraine, through the reaction of 3-octylpyrrole and squaric acid, and then co-doped it with phenanthrenequinone (PQ) into poly(methyl methacrylate) (PMMA) to improve the holographic data storage characteristics of the photopolymer. The photopolymers co-doped with relatively small amounts of PSQ3 exhibited greatly improved holographic recording characteristics, including superior diffraction efficiency and dynamic range (M#). Among the samples co-doped with PQ and PSQ3, the maximum diffraction efficiency reached 54.8% (cf. 9.0% for PMMA/PQ) without further downgrade and the value of M# reached 1.05 (cf. 0.46 for PMMA/PQ). Therefore, the holographic data storage characteristics of the photopolymer PMMA/PQ were improved through co-doping with PSQ3.