Preparation and Optical and Mechanical Properties of Polyimide/Inorganic Nanoparticles Hybrid Thin Films

• Main Authors: Yu, Hui Huan, 游輝桓
• Other Authors: Yu, Yang Yan
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/63469222115505523481

碩士 === 明志科技大學 === 材料工程研究所 === 100 === In this study, the polyimide–titania hybrid thin films and precursors were prepared from a soluble polyimide with carboxylic acid end groups and titanium butoxide by sol-gel process. The effects of TiO2 content on the hybrid film properties and the optimum operating conditions were also investigated. FTIR spectra indicated that the imidization was complete and the cross-linking Ti-O-Ti network formed at 600–800 cm-1.The XRD diffraction patterns prove that the crystal phase of titania is anatase.TGA and DSC analysis showed that the glass transition temperature increased as the titania content in hybrid thin films increased and the char yields of PT0-PT90 hybrid materials are estimated as 45.0–97.0 wt% by a linear relationship. The results of FESEM and AFM showed that all the prepared hybrid films had a good film formability and planarity. The dielectric constants of the hybrid thin films,PT10–PT90 was 1.54-5.52 at various frequencies. TEM indicated results the formation of nanocrystalline-titania domains of around 3–6 nm in the hybrid films. The ellipsometer results suggest that the prepared hybrid films have tunable refractive index (1.61 < n < 2.01) in the visible range. The UV-vis analysis showed that the prepared hybrid thin films had the good optical properties. Moreover, the prepared polyimide/titania hybrid thin films were further applied to develop a three layer antireflective (AR) coating on the glass substrate. The results showed that the average reflectance of the AR coating on the glass substrate was 0.495. The transparency at 550nm was greater than 90% for AR coatings on the glass substrates. The hardness and the elastic modulus of PT0-PT60 increased from 0.4 to 1.65 GPa and 5.56 to 20.57 GPa, respectively. It was found that these results indicate that the polyimide-titania hybrid materials have potential applications for optical devices.