摘要
Solid-stated smart polymers responsive to external stimuli have attracted much attention for potential application in the field of photoelectron devices,logic gates,sensor,data storage and security.However,it is a bigger challenge for polymers than that for small molecules in solid state to acquire stimuli-responsive properties,because polymers with high molecular weight are not as easy to change the packing structure as small molecules under external stimulation.Here,a D-A type alternating copolymer PTMF-o containing 3,4-bisthienylmaleimide(A unit)and fluorene(D unit)is designed and synthesized.Upon irradiation of sunlight,PTMF-o film exhibits a photo-response with the color altering from purple to colorless.It is attributed to the structure of copolymer transformed from ring-opening form(PTMF-o)to ring-closure form(PTMF-c),resulting from the oxidative photocyclization of 3,4-bisthienylmaleimide unit.Consequently,the ability of charge transfer(CT)from fluorene to 3,4-bisthienylmaleimide unit in PTMF-o can be easily weakened by light stimuli.PTMF-o film displays a WORM-type resistive storage performance for the strong CT.Interestingly,after exposure,the electrical memory behavior in situ transfers into FLASH type,due to weak CT in PTMF-c.PTMF-o film can also be employed as smart material to construct NAND and NOR logic gates by using light as input condition.The work provides a simple way to modify the electronic properties of polymers and realize stimuli-response in solid states.
基金
This work was financially supported by the National Natural Science Foundation of China(Nos.22075044 and 21574021)
the Natural Science Foundation of Fujian Provinee(No.2018J01670)
Educational Commission of Fujian Province(No.JAT170129)
the Scientific Research Starting Foundation for researchers with PhD of Fujian Normal University.
