Polymerization-induced self-assembly(PISA)is an emerging method for the preparation of block copolymer nano-objects at high concentrations.However,most PISA formulations have oxygen inhibition problems and inert atmos...Polymerization-induced self-assembly(PISA)is an emerging method for the preparation of block copolymer nano-objects at high concentrations.However,most PISA formulations have oxygen inhibition problems and inert atmospheres(e.g.argon,nitrogen)are usually required.Moreover,the large-scale preparation of block copolymer nano-objects at room temperature is challenging.Herein,we report an enzyme-assisted photoinitiated polymerization-induced self-assembly(photo-PISA)in continuous flow reactors with oxygen toleranee.The addition of glucose oxidase(GOx)and glucose into the reaction mixture can consume oxygen efficiently and constantly,allow the flow photo-PISA to be performed under open-air conditions.Polymerization kinetics indicated that only a small amount of GOx(0.5 μmol/L)was needed to achieve the oxygen tolerance.Block copolymer nano-objects with different morphologies can be prepared by varying reaction conditions including the degree of polymerization(DP)of core-forming block,monomer concentration,reaction temperature,and solvent composition.We expect this study will provide a facile platform for the large-scale production of block copolymer nano-objects with different morphologies at room temperature.展开更多
Polyethylene terephthalate(PET)and polyethylene(PE)fibers were surface photo-grafted with acrylic acid(AA)by using UV irradiation photochemical initiationduring a continuous winding process within 1-2 min-utes.The gra...Polyethylene terephthalate(PET)and polyethylene(PE)fibers were surface photo-grafted with acrylic acid(AA)by using UV irradiation photochemical initiationduring a continuous winding process within 1-2 min-utes.The grafted fibers were characterized by measure-ments of dye uptaking,moisture regain,pull-out forcesof monofilament from cured matrix,as well as by analy-sis of ESCA and ATR-FTIR spectra.All these resultsconfirm that the surface behavior of the UV-irradiationgrafted fibers was greatly improved.It was also provedthat the original excellent mechanical properties of the fi-bers were well-retained after the surface grafting treat-ment.展开更多
Bis (7- diethylaminocoumarin) ketone- 3(DACK) and diphenyliodonium salt (DPIO)combination as an effective photoinitiation system for radical polymerization has been investigated. The sensitized photolysis of DACK/DPIO...Bis (7- diethylaminocoumarin) ketone- 3(DACK) and diphenyliodonium salt (DPIO)combination as an effective photoinitiation system for radical polymerization has been investigated. The sensitized photolysis of DACK/DPIO leads to bleaching of DACK and decomposition of DPIO to generate initiating radical species. The electron transfer sensitization occurs mainly from the triplet state of DACK. The photobleaching obeyed a second-order kinetics and the rate constant was evaluated to be 31.3mol^(-1)·1·s^(-1) Photopolymerization of MMA initiated by DACK/DPIO was carried out in acetonitrile solution. The polymerization rate was found to be proportional to the concentration of DACK, DPIO and MMA with the exponents of 0.34, 0.40 and 1.0 respectively. The initiated efficiency is comparable to those of small molecular ketones.The sensitized photoinitiation mechanism has been discussed.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(Nos.21971047 and 21504017)Innovation Project of Education Department in Guangdong(No.2018KTSCX053)+1 种基金Y.C.acknowledges the support from Guangdong Special Support Program(No.2017TX04N371)J.T.acknowledges the support from Pearl River Young Scholar of Guangdong.
文摘Polymerization-induced self-assembly(PISA)is an emerging method for the preparation of block copolymer nano-objects at high concentrations.However,most PISA formulations have oxygen inhibition problems and inert atmospheres(e.g.argon,nitrogen)are usually required.Moreover,the large-scale preparation of block copolymer nano-objects at room temperature is challenging.Herein,we report an enzyme-assisted photoinitiated polymerization-induced self-assembly(photo-PISA)in continuous flow reactors with oxygen toleranee.The addition of glucose oxidase(GOx)and glucose into the reaction mixture can consume oxygen efficiently and constantly,allow the flow photo-PISA to be performed under open-air conditions.Polymerization kinetics indicated that only a small amount of GOx(0.5 μmol/L)was needed to achieve the oxygen tolerance.Block copolymer nano-objects with different morphologies can be prepared by varying reaction conditions including the degree of polymerization(DP)of core-forming block,monomer concentration,reaction temperature,and solvent composition.We expect this study will provide a facile platform for the large-scale production of block copolymer nano-objects with different morphologies at room temperature.
文摘Polyethylene terephthalate(PET)and polyethylene(PE)fibers were surface photo-grafted with acrylic acid(AA)by using UV irradiation photochemical initiationduring a continuous winding process within 1-2 min-utes.The grafted fibers were characterized by measure-ments of dye uptaking,moisture regain,pull-out forcesof monofilament from cured matrix,as well as by analy-sis of ESCA and ATR-FTIR spectra.All these resultsconfirm that the surface behavior of the UV-irradiationgrafted fibers was greatly improved.It was also provedthat the original excellent mechanical properties of the fi-bers were well-retained after the surface grafting treat-ment.
文摘Bis (7- diethylaminocoumarin) ketone- 3(DACK) and diphenyliodonium salt (DPIO)combination as an effective photoinitiation system for radical polymerization has been investigated. The sensitized photolysis of DACK/DPIO leads to bleaching of DACK and decomposition of DPIO to generate initiating radical species. The electron transfer sensitization occurs mainly from the triplet state of DACK. The photobleaching obeyed a second-order kinetics and the rate constant was evaluated to be 31.3mol^(-1)·1·s^(-1) Photopolymerization of MMA initiated by DACK/DPIO was carried out in acetonitrile solution. The polymerization rate was found to be proportional to the concentration of DACK, DPIO and MMA with the exponents of 0.34, 0.40 and 1.0 respectively. The initiated efficiency is comparable to those of small molecular ketones.The sensitized photoinitiation mechanism has been discussed.
