Optically Ambidextrous Reflection and Luminescence in Self-Organized Left-Handed Chiral Nematic Cellulose Nanocrystal Films  

作　　者：Jiawei Tao Chen Zou Haijing Jiang Mei Li Di Lu Stephen Mann Yan Xu 

机构地区：[1]State Key Laboratory of Inorganic Synthesis and Preparative Chemistry,Jilin University,Changchun 130012 [2]Centre for Organized Matter Chemistry,School of Chemistry,University of Bristol,Bristol BS81TS

出　　处：《CCS Chemistry》2021年第3期932-945,共14页中国化学会会刊（英文）

基　　金：was funded by NNSF China(grant nos.21975095,21671079,and 21373100);111 project(grant no.B17020);JLU International Co-advisorship Program(grant no.419020201362);JLU International Collaboration Program(grant no.45119031C015);the State Key Laboratory of Inorganic Synthesis and Preparative Chemistry of JLU(grant no.1G3194101461).

摘　　要：Defect-embedded chiral nematic organizations are attractive due to their light manipulation ability that is crucial for photonic applications.Self-assembly of cellulose nanocrystals(CNC)forms a left-handed chiral nematic structure,which makes simultaneous reflection of left-handed circularly polarized(LCP)and right-handed circularly polarized(RCP)light a challenging task.Herein,we present unprecedented evidence that self-organized CNC films with left-handed helical sense and photonic bandgaps(PBG)display ambidextrous CP light reflection with peak reflectivity up to 68%and transform spontaneous photoluminescence to RCP and LCP luminescence with respective|glum|values up to 0.796 and 0.120.These ambidextrous chiroptical properties originate from a left-handed chiral nematic structure consisting of a nematic-like phase,acting as a half-wave retarder,sandwiched between two PBG layers.The latter are spontaneously intercalated into the left-handed helicoids by rapid gelation of CNC colloidal suspensions.We demonstrate that the ambidextrous chiroptical properties can be manipulated by changes in evaporation temperatures,concentrations,and characteristics of CNC suspensions.We showcase the potential of defect-embedded chiral nematic CNC films for the sustainable and scalable development of anti-counterfeiting optical labels.

关 键 词：cellulose nanocrystals chiral nematic materials SELF-ORGANIZATION optically ambidextrous selective reflection circularly polarized luminescence 

分 类 号：O62[理学—有机化学]