Sensitive Mechanochromisms Based on a Polymer Bilayer Structure

• 作 者: Songshan Zeng Dianyun Zhang Wenhan Huang Zhaofeng Wang Stephan G.Freire Xiaoyuan Yu Andrew T.Smith Emily Y.Huang Helen Nguon Luyi Sun
• 机 构: Department of Chemical & Biomolecular Engineering and Polymer Program,Institute of Materials Science
• 出 处: 中国化学会2017全国高分子学术论文报告会
• 发表日期: 2017年10期
• 关键词: mechanochromism crackformation strain luminescence

　　We have designed a series of mechanochromic devices inspired by nature with the capabilities of changing transparencyand “switching on/off” luminescence in response to mechanical stimuli.The key to accomplish these excellent opticalproperties is to control strain-induced surface engineering,that is,the longitudinal cracks opening and transverse invaginatedfolds.All of these devices are comprised of a rigid thin layer atop polydimethylsiloxane(PDMS)based elastomer,which canbe facilely and quickly fabricated.For transparency change mechanochromism,the folds and cracks with excellent lighttrapping and scattering capabilities can endow high opaqueness to the originally highly transparent samples.The evolution ofcrack opening and fold–ridge mechanisms are captured through finite analysis that incorporates damage and cracks in therigid thin layer.For luminescent mechanochromism,the strain-tunable cracks on the UV shield layer act as “gates” tomediate the traveling of UV light to “switch on/off” the luminescence of mechanochromism.This device exhibits aremarkably high strain responsive sensitivity,demonstrating an excellent sensing capability for detecting mechanical failureor damage.All the mechanochromisms also show outstanding durability and reversibility.