Asymmetric Free-Standing 2-D Photonic Crystal Films and Their Janus Particles

详细信息    查看全文

• 作者：Jian-Tao Zhang ; Xing Chao ; Sanford A. Asher
• 刊名：The Journal of the American Chemical Society
• 出版年：2013
• 出版时间：July 31, 2013
• 年：2013
• 卷：135
• 期：30
• 页码：11397-11401
• 全文大小：401K
• 年卷期：v.135,no.30(July 31, 2013)
• ISSN：1520-5126

文摘

We report the fabrication of large area, thin asymmetric free-standing two-dimensional (2-D) photonic crystals. We fabricate large area 2-D close-packed monodisperse polystyrene (PS) particle monolayers at air/water interfaces by using our needle tip flow method. We then layer tetraethyl orthosilicate (TEOS) onto the 2-D array to form a thin TEOS layer on the 2-D particle array on water. The hemispheres of PS particles located within the TEOS phase swell such that the adjacent particle hemispheres fuse. After TEOS evaporation, we obtain a free-standing connected photonic crystal film of hemispheres that efficiently diffracts light. The other side of the photonic crystal film consists of a fused connecting thin, flat sheet. Reactive ion etching (RIE) of the asymmetric films forms unusual, rough particle 2-D arrays and 2-D flower-like arrays. Mechanical abrasion allows one to separate the resulting novel Janus particles.