Browsing by Author "Ko, Cheng-Jung"

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Co-doping with polysquaraine enhances the holographic optical data storage of PMMA/PQ photopolymers
(2011)
Ko, Cheng-Jung
;
Chang, Yeh-Lu
;
Hsiao, Yi-Nan
;
Chen, Po-Lin
;
Lin, Shiuan-Huei
In this study, we synthesised 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.
Effect of TiO2 on thermal and adhesive characteristics of poly(imide siloxane)/TiO2 hybrid films
(2012-05-05)
Ko, Cheng-Jung
;
Tseng, I-Hsiang
;
Whang, Wha-Tzong
;
Tsai, Mei-Hui
;
材料科學與工程學系
A novel poly(imide siloxane)/titania (PIS/TiO2) hybrid film was fabricated by sol-gel process via in situ formation of TiO2 within PIS matrix. Poly(amic acid siloxane) (PAAS) was prepared from 4,4'-oxydiphthalic anhydride, 2,2-bis [4-(4-aminophenoxy) phenyl] propane, and alpha,omega-bis(3-aminopropyl)polydimethylsiloxane (APPS). Chelating agent, acetylacetone, and catalyst-free polymerization were used to reduce the rate of hydrolysis of titanium alkoxide in the PAAS. X-ray photoelectron spectroscopy data showed that the presence of APPS promotes the Ti surface composition of PIS/TiO2 hybrid film. The effects of TiO2 and APPS contents on the characteristics of surface, thermostability, coefficient of thermal expansion (CTE), and the strength of adhesion were investigated. The presence of TiO2 on the surface of the hybrid films enhanced the adhesive strength at the interface of PIS/TiO2 hybrid film and copper foil. When more TiO2 was incorporated into the PIS matrix, the PIS/TiO2 hybrid film exhibited lower CTE while retaining favorable mechanical and thermal properties. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Holographic recording characteristics and physical mechanism of zinc methacrylate/nitroaniline-co-doped poly(methyl methacrylate)/9,10-phenanthrenequinone photopolymers
(2013-06-01)
Ko, Cheng-Jung
;
Chen, Po-Lin
;
Hsiao, Yi-Nan
;
Lin, Shiuan-Huei
;
Whang, Wha-Tzong
In this study we developed an approach to improve the characteristics of photopolymers for holographic data storage. Through codoping 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 PQ-doped PMMA through codoping with DMNA and 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. POLYM. ENG. SCI., 2013. (c) 2012 Society of Plastics Engineers
Nitroanilines enhancing the holographic data storage characteristics of the 9,10-phenanthrenequinone-doped poly(methyl methacrylate) photopolymer
(2013-01-05)
Ko, Cheng-Jung
;
Hsiao, Yi-Nan
;
Lin, Shiuan-Huei
;
Chen, Po-Lin
;
Whang, Wha-Tzong
This article describes an approach toward improving the characteristics of a photopolymer for holographic data storage application. The maximum diffraction efficiency (?max) and dynamic range (M#) of 9,10-phenanthrenequinone (PQ)-doped poly(methyl methacrylate; PMMA) both improved significantly after co-doping with one of three nitroanilinesN,N-dimethyl-4-nitroaniline (DMNA), N-methyl-4-nitroaniline (MNA), and 4-nitroaniline (pNA). In particular, the value of ?max increased from 38% for the PMMA/PQ system to 72% 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. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2012