Novel poly(dimethylsiloxane)(PDMS)doped with two diferent spiropyran derivatives(SP)were investigated as potential candidates for the preparation of elastomeric waveguides with UV-dependent optical properties.First,fr...Novel poly(dimethylsiloxane)(PDMS)doped with two diferent spiropyran derivatives(SP)were investigated as potential candidates for the preparation of elastomeric waveguides with UV-dependent optical properties.First,free-standing flms were prepared and evaluated with respect to their photochromic response to UV irradiation.Kinetics,reversibility as well as photofatigue and refractive index of the SP-doped PDMS samples were assessed.Second,SP-doped PDMS waveguides were fabricated and tested as UV sensors by monitoring changes in the transmitted optical power of a visible laser(633 nm).UV sensing was successfully demonstrated by doping PDMS using one spiropyran derivative whose propagation loss was measured as 1.04 dB/cm at 633 nm,and sensitivity estimated at 115%change in transmitted optical power per unit change in UV dose.The decay and recovery time constants were measured at 42 and 107 s,respectively,with an average UV saturation dose of 0.4 J/cm2.The prepared waveguides exhibited a reversible and consistent response even under bending.The sensor parameters can be tailored by varying the waveguide length up to 21 cm,and are afected by white light and temperatures up to 70℃.This work is relevant to elastomeric optics,smart optical materials,and polymer optical waveguide sensors.展开更多
Two series of novel spiropyran derivatives containing a mesogenic group have been prepared. Their photochromic behaviors were first investigated with the aid of absorption spectral measurements.
Donor-acceptor Stenhouse adducts(DASAs)as a species of novel photochromic molecules,have been developing rapidly and attracting broad researchers’sights since 2014.DASAs show visible/near-infrared(NIR)light induced l...Donor-acceptor Stenhouse adducts(DASAs)as a species of novel photochromic molecules,have been developing rapidly and attracting broad researchers’sights since 2014.DASAs show visible/near-infrared(NIR)light induced linear-to-cyclic isomerization and heat induced cyclic-to-linear isomerization,therefore they are attractive in photoresponsive hydrogels,drug delivery,cell culturing and tissue engineering.As a series of well-known photoresponsive molecules,spiropyrans(SPs)show similar molecular properties and comparable photoswitching with DASAs.UV light triggers closed-to-open(also known as spirocyclic(SC)-to-merocyanine(MC))isomerization of SPs,while the reversed open-to-closed isomerization occurs under visible light or heat.Light irradiation switches the molecular color,scale,geometry,and polarity of SPs and DASAs reversibly.Since the researches on DASAs are still in the infancy,the chemical structures,isomerization mechanisms and potential applications need to be further investigated and explored.The well-studied SPs have important reference values to the comprehensive developments of DASAs.In the present review,we summarized,compared and discussed SPs and DASAs with regards to their molecular structures,synthesis,photoswitching and applications.We also make our perspective on the developments of DASA in future.展开更多
A series of spiropyrans with a polyaromatic or heteroaromatic pendant was synthesized conveniently. Their photochromic behaviors were investigated with the aid of absorption spectral measurements. The results indicate...A series of spiropyrans with a polyaromatic or heteroaromatic pendant was synthesized conveniently. Their photochromic behaviors were investigated with the aid of absorption spectral measurements. The results indicated that the compounds with the same parent spiropyran but different aromatic pendant show significantly different photochromic properties. This may be due to the π-π orbital interaction between the polyaromatic pendant and the open photomerocyanine form of spiropyran. The results obtained are very useful in the molecule design area.展开更多
基金Fonds de Recherche du Québec-Nature et Technologies(grant number 304946)andÉTS Research Chair in Engineering Marcelle-Gauvreau.CAZ would like to thank STEPPE,LACIME,and LIPEC personnel and friends for their assistance and support with the experiments.
文摘Novel poly(dimethylsiloxane)(PDMS)doped with two diferent spiropyran derivatives(SP)were investigated as potential candidates for the preparation of elastomeric waveguides with UV-dependent optical properties.First,free-standing flms were prepared and evaluated with respect to their photochromic response to UV irradiation.Kinetics,reversibility as well as photofatigue and refractive index of the SP-doped PDMS samples were assessed.Second,SP-doped PDMS waveguides were fabricated and tested as UV sensors by monitoring changes in the transmitted optical power of a visible laser(633 nm).UV sensing was successfully demonstrated by doping PDMS using one spiropyran derivative whose propagation loss was measured as 1.04 dB/cm at 633 nm,and sensitivity estimated at 115%change in transmitted optical power per unit change in UV dose.The decay and recovery time constants were measured at 42 and 107 s,respectively,with an average UV saturation dose of 0.4 J/cm2.The prepared waveguides exhibited a reversible and consistent response even under bending.The sensor parameters can be tailored by varying the waveguide length up to 21 cm,and are afected by white light and temperatures up to 70℃.This work is relevant to elastomeric optics,smart optical materials,and polymer optical waveguide sensors.
基金The auth ors thank the National Natural Science Foundation of China for the financial support．(Grant Nos．20402009 and 20372039)．
文摘Two series of novel spiropyran derivatives containing a mesogenic group have been prepared. Their photochromic behaviors were first investigated with the aid of absorption spectral measurements.
基金the financial support from the National Natural Science Foundation of China(61805034)Guangdong Basic and Applied Basic Research Foundation(2019A1515110678)Opening Project of State Key Laboratory of Polymer Materials Engineering(Sichuan University)(Grant No.sklpme2018-4-28).
文摘Donor-acceptor Stenhouse adducts(DASAs)as a species of novel photochromic molecules,have been developing rapidly and attracting broad researchers’sights since 2014.DASAs show visible/near-infrared(NIR)light induced linear-to-cyclic isomerization and heat induced cyclic-to-linear isomerization,therefore they are attractive in photoresponsive hydrogels,drug delivery,cell culturing and tissue engineering.As a series of well-known photoresponsive molecules,spiropyrans(SPs)show similar molecular properties and comparable photoswitching with DASAs.UV light triggers closed-to-open(also known as spirocyclic(SC)-to-merocyanine(MC))isomerization of SPs,while the reversed open-to-closed isomerization occurs under visible light or heat.Light irradiation switches the molecular color,scale,geometry,and polarity of SPs and DASAs reversibly.Since the researches on DASAs are still in the infancy,the chemical structures,isomerization mechanisms and potential applications need to be further investigated and explored.The well-studied SPs have important reference values to the comprehensive developments of DASAs.In the present review,we summarized,compared and discussed SPs and DASAs with regards to their molecular structures,synthesis,photoswitching and applications.We also make our perspective on the developments of DASA in future.
文摘A series of spiropyrans with a polyaromatic or heteroaromatic pendant was synthesized conveniently. Their photochromic behaviors were investigated with the aid of absorption spectral measurements. The results indicated that the compounds with the same parent spiropyran but different aromatic pendant show significantly different photochromic properties. This may be due to the π-π orbital interaction between the polyaromatic pendant and the open photomerocyanine form of spiropyran. The results obtained are very useful in the molecule design area.
