Deformation of amorphous azobenzene-containing polymer films induced by polarized light

Photomechanical response of amorphous polymer films containing azobenzene chromophores in side chains is studied. By invoking the trans-cis isomerization mech- anism, the steady-state deformation of the film induced by uniform illumination of linearly polarized light is obtained analytically. The deformation turns out to be of entropic origin,produced to compensate the entropy decrease due to photo-induced redistribution of azobenzene chromophores normal to the polarization direction. The predicted elongation direction of the film is consistent with previous experimental observations.

Temperature Dependence of Photoinduced Birefringence in an Azobenzene Polymer

The photoinduced birefringence in an azobenzene polymer is investigated at different temperatures between -20℃ to 50℃. It is found that there is a peak value of photoinduced birefringence in the temperature dependence of the photoinduced birefringence under a certain pumping intensity. With the pump light in 90mW/cm^2, the peak value of the photoinduced birefringence appeared at about 0℃ C. The effect of temperature on the photoinduced birefringence is discussed using the competition mechanism between the photoinduced reorientation and the thermal random motion.

Promote the conductivity of solid polymer electrolyte at room temperature by constructing a dual range ionic conduction path

Poly(ethylene oxide)(PEO)is a classic matrix model for solid polymer electrolyte which can not only dissociate lithium-ions(Li^(+)),but also can conduct Li^(+) through segmental motion in long-range.However,the crystal aggregation state of PEO restricts the conduction of Li^(+) especially at room temperature.In this work,an amorphous polymer electrolyte with ethylene oxide(EO)and propylene oxide(PO)block structure(B-PEG@DMC)synthesized by the transesterification is firstly obtained,showing an ionic conductivity value of 1.1×10^(5) S/cm at room temperature(25℃).According to the molecular dynamics(MD)simulation,the PO segments would lead to an inconsecutive and hampered conduction of Li^(+),which is not beneficial to the short range conduction of Li^(+).Thus the effect of transformation of aggregation state on the improveme nt of ionic conductivity is not eno ugh,it is n ecessary to further consider the differe nt coupled behaviours of EO and PO segments with Li^(+).In this way,we blend this amorphous polymer(B-PEG@DMC)with PEO to obtain a dual range ionic conductive solid polymer electrolyte(D-SPE)with further improved ionic conductivity promoted by constructing a dual range fast ionic conduction,which eventually shows a further improved ionic conductivity value of 2.3×10^(5) S/cm at room temperature.

Photo-controllable room-temperature phosphorescence of organic photochromic polymers based on hexaarylbiimidazole

Pure organic room-temperature phosphorescent(RTP)materials have been attracting widespread attention due to the unique properties and broad applications.However,RTP materials with the adjustable photochromic property are still a challenge.Based on this,two polymers containing hexaarylbiimidazole are strategically designed with dual emission of both fluorescence and phosphorescence.Furthermore,both polymers show sensitive photochromic responses from faint yellow to brown upon exposure to ultraviolet light.This study can enrich pure organic luminescent systems and provide new ideas for functional RTP materials.

Influence of the alkyl side chain length on the room-temperature phosphorescence of organic copolymers

Pure organic room-temperature phosphorescence(RTP)materials have attracted wide attention owing to their excellent luminescent properties and great potential in various applications.In this work,iminostilbene and its analogues are applied to realize RTP emission by copolymerizing with acrylamide.It can be concluded that the growth of alkane chain in monomers can enhance the lifetime and photoluminescence quantum yield of RTP emission,and polymers with the larger conjugated structure of the monomer show a longer RTP emission wavelength.This work provides a series of new pure organic RTP materials and might provide new thoughts for designing more advanced and superior RTP materials.