標題: Reversibly Thermoswitchable Two-Dimensional Periodic Gratings Prepared from Tethered Poly(N-isopropylacrylamide) on Silicon Surfaces
作者: Chen, Jem-Kun
Wang, Jing-Hong
Cheng, Chih-Chia
Chang, Jia-Yaw
應用化學系
Department of Applied Chemistry
關鍵字: PNIPAAm brush;two-dimensional periodic grating;refractive index
公開日期: 24-四月-2013
摘要: In this study we used atom transfer radical polymerization to graft poly(N-isopropylacrylamide) (PNI-PAAm) onto flat Si substrates. We then applied very large-scale integration and reactive ion etching sequentially to generate 200-nm-scale hole arrays of tethered PNIPAAm as two-dimensional periodic concave gratings (2DPCGs) on the Si surfaces. The hole array structures of tethered PNIPAAm could be created and erased reversibly at 25 and 40 degrees C, respectively, leading to significant. changes in the effective refractive index (n(eff)). The values of neff of the 2DPCGs were related to the depth of their holes generated after etching for various times, resulting in a color change from blue to red that could be observed by the naked eye at incident angles of 10-20 degrees. Moreover, we used effective-medium theory to calculate the filling factors of air inside the 2DPCGs to verify the structural changes of the tethered PNIPAAm. Such designed 2DPCGs of thermorespective hydrogel films have potential applications in temperature-responsive optical devices [e.g., as antireflection structured surfaces (ARSs)] that operate at both visible and near-infrared wavelengths.
URI: http://dx.doi.org/10.1021/am4010072
http://hdl.handle.net/11536/21663
ISSN: 1944-8244
DOI: 10.1021/am4010072
期刊: ACS APPLIED MATERIALS & INTERFACES
Volume: 5
Issue: 8
起始頁: 2959
結束頁: 2966
顯示於類別:期刊論文


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  1. 000318205000021.pdf