Fabrication of binary colloidal crystal opal films by horizontal deposition method

• Main Authors: Chia-wei Wang, 王嘉偉
• Other Authors: Hui Chen
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/34210108628876573616

碩士 === 國立中央大學 === 化學工程與材料工程學系 === 102 === This study focuses on preparation of monodisperse submicron-scale and nano-sacle polymer spheres and the films forming ability by these two kinds polymer spheres. Submicrospheres with different particle sizes, glass transition temperatures (Tgs) and carboxyl groups were prepared. On the other hand, nanospheres with different Tgs were also prepared. The photonic crystal films with mechanical properties can be improved by self-assembly method of these two kinds of spheres. The five topics were discussed in this study. The first topic was preparation and characterization of monodisperse poly(methyl methacrylate-co-methacrylic acid) submicrospheres via soap-free emulsion polymerization. Different particle sizes from 82 nm to 502 nm were prepared by adding 1 g to 20 g monomers. In second topic, different Tgs submicrospheres were prepared by copolymerization of butyl acrylate (BA) and MMA. When the weight percentage of BA increased from 0 wt% to 88 wt%, the Tg of submicrospheres decreased from 118 °C to -5.6 °C. Photonic crystal films of these submicrospheres were then studied to identify the relationship between variation in Tgs and the optical properties. In third topic, the monodisperse low Tg nanospheres were prepared and mixed with submicrospheres to form self-assemble binary colloidal crystal (BCC) films. The results showed that submicrospheres surrounded by soft nanospheres and formed like core-shell structure with a regular arrangement. The film forming properties of hardness film prepared from high Tg submicrospheres improved to 5B pencil hardness by the aid of 20 wt% low Tg nanospheres. In fourth topic, the monodisperse high Tg nanospheres were prepared and mixed with submicrospheres to form self-assembly BCC films. The results showed that submicrospheres surrounded by hard nanospheres and formed a photonic crystal framework to prevent the collapse of the low Tg submicrospheres during film formation. According to the stress-strain diagram, the mechanical properties of BCC films were able to tune by the Tg of submicrospheres and the blended content of high Tg nanospheres. Base on the BCC film prepared by the Tg 0 °C submicrospheres and 20 wt% of high Tg nanospheres, the ultimate tensile strength and maximum elongation were able to achieve 0.78 MPa and 222 %. In fifth topic, submicrospheres with different carboxyl groups were prepared with MAA 0 wt% to 30 wt%. The results showed that the mechanical properties of the film changed gradually from elastic to brittle. When adding 20 wt% high Tg nanosphers into the film, the MAA ratio of submicrospheres changed from 0 wt% to 8 wt%, the ultimate tensile strength were able to increase from 1.3 MPa to 3.5 MPa and maximum elongation were able decrease from 359 % to 13 %.