|DC.description||National Central University||en_US|
首先，利用不同甲基丙烯酸甲酯(MMA)單體克數製備出不同粒徑大小之次微米球，而MMA單體添加量4 g-10 g所製備之次微米球經自組裝過程後，其光子晶體能隙位置落於可見光範圍400-700 nm內。藉由Flory-Fox方程式調整丙烯酸丁酯(BA)與MMA單體之進料比可以製備具不同Tg之次微米球，當BA之重量百分比增加時，便可使次微米球之Tg由118.5 °C降低至-5.6 °C，且粒徑均相當均一。將具不同Tg次微米球於高低環境溫度下自組裝後，由結果顯示50 °C高溫環境溫度下有助於自組裝排列更為規則。Tg 40 °C以上之次微米球於SEM下呈現圓球狀並可顯現出結構性色彩。Tg 30 °C以下之次微米球於SEM下呈現平膜狀且不具備結構性色彩，但薄膜具有良好的成膜性質。薄膜的機械性質隨著次微米球的Tg降低，逐漸由脆性高分子轉變為彈性高分子。
|dc.description.abstract||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 %.
|DC.subject||Soap-free emulsion polymerization||en_US|
|DC.subject||horizontal deposition method||en_US|
|DC.subject||binary colloidal crystal||en_US|
|DC.title||Fabrication of binary colloidal crystal opal films by horizontal deposition method||en_US|
|DC.publisher||National Central University||en_US|