The exploitation of new green polymerization avenues for the effective synthesis of polymers by reversible-deactivation radical polymerization plays a critical role in pursuing the development of polymeric materials.I...The exploitation of new green polymerization avenues for the effective synthesis of polymers by reversible-deactivation radical polymerization plays a critical role in pursuing the development of polymeric materials.In this work,serials of deep eutectic solvents(DES)with intermolecular-hydrogen-bonding interaction were constructed as catalysts and medium for actuating reversible complexation-mediated polymerization(RCMP)for the first time,yielding methacrylate polymers with high monomer conversion and narrow dispersion molecular weight in both water and oil systems.The mechanism and elementary reaction of RCMP were explored deeply,revealing that the complexation of initiator with DES to generate radicals was a ratecontrolling step and intermolecular-hydrogen-bond was primary factor to influence polymerization rate.Moreover,the insights of density functional theory calculations revealed that negative electrostatic potential ensured nucleophilic capacity.This investigation demonstrated the considerable potential of DES for RCMP,which is anticipated for other polymerization applications as a novel medium mode.展开更多
Dynamic self-assembly processes occurring out of thermodynamic equilibrium underlie many forms of adaptive and intelligent behaviors in natural systems.Because of the continuous input of energy,the dynamic self-assemb...Dynamic self-assembly processes occurring out of thermodynamic equilibrium underlie many forms of adaptive and intelligent behaviors in natural systems.Because of the continuous input of energy,the dynamic self-assembly provides the opportunity for creating structures that are unattainable in equilibrium state.In this paper,we propose a strategy in the dynamic self-assembly of amphiphilic block copolymers regulated by reversible chemical reaction.By time-dependently tuning the reaction direction in the simulations,the amphiphilicity of building block keeps changing periodically.Relying on this dynamic process,we can obtain exotic self-assembled vesicle with surface pores which is otherwise metastable in an equilibrium state.The effects induced by the type of chemical reaction and the reaction period are discussed.Only at short reaction period in suitable reversible reaction,novel self-assembly structure emerges.It is attributed to the competition of reaction and diffusion in the dynamic process,by which the local component of building blocks alters a lot,leading to large local surface tension resulting in the formation of perforated vesicle.In order to predict the assembled structure in a dynamic process,we build up the relationship between component ratio P,the diffusion effect parameter Pdiff and assembled structures.The dynamic self-assembly regulated by chemical reaction holds great promise as a rational strategy to realize exotic functional materials that are not easily obtained in equilibrium.展开更多
Reversible addition-fragmentation chain transfer(RAFT)-mediated polymerization-induced self-assembly(PISA)of star block copolymer and linear block copolymer using a binary mixture of a star-like macro-RAFT agent and a...Reversible addition-fragmentation chain transfer(RAFT)-mediated polymerization-induced self-assembly(PISA)of star block copolymer and linear block copolymer using a binary mixture of a star-like macro-RAFT agent and a linear macro-RAFT agent is reported.With this formulation,star block copolymer and diblock copolymer were formed simultaneously to generate colloidally stable star/linear block copolymer assemblies.Size exclusion chromatography(SEC)analysis confirmed the presence of two types of polymers in the final samples.The molar ratio of the star-like macro-RAFT agent and the linear macro-RAFT agent has a significant impact on the morphology of polymer assemblies.It was found that increasing the amount of star-like macro-RAFT agent facilitated the formation of higher-order morphologies.Additionally,effects of other reaction parameters including the length/number of the arm of the star-like macro-RAFT agent,degree of polymer(DP),monomer concentration on the morphology of star/linear block copolymer assemblies were also investigated.We expect that this work will offer new possibilities for the scalable preparation of polymer assemblies with unique structures and functions.展开更多
Reverse addition\|fragmentation chain transfer (RAFT) polymerizatin of MAn with St is reported aiming at the synthesis of a well\|defined alternating copolymer of MAn with St.The results show that the polymers possess...Reverse addition\|fragmentation chain transfer (RAFT) polymerizatin of MAn with St is reported aiming at the synthesis of a well\|defined alternating copolymer of MAn with St.The results show that the polymers possess predetermined molecular weight and molecular weight distribution as narrow as 1 2. A novel well\|defined block copolymer P(MAn\| alt \|St)\| b \|PSt has also been prepared by the copolymerization of MAn with excess amount of St in molar feed via RAFT process.展开更多
A series of β-cyclodextrin-conjugated 4-arm poly（ethylene glycol）-poly（lactide-co-glycolide） （4-arm PEG-PLGA） copolymers were synthesized by a ring-opening polymerization of D,L-lactide and glycolide using 4-a...A series of β-cyclodextrin-conjugated 4-arm poly（ethylene glycol）-poly（lactide-co-glycolide） （4-arm PEG-PLGA） copolymers were synthesized by a ring-opening polymerization of D,L-lactide and glycolide using 4-arm PEG as initiator, and then conjugated with mono（6-ethylenediamine-6-deoxy）- β-cyclodextrin （CDen） or ethylenediamino-bridged bis- β-CD （BCDen）. The chemical structures of copolymers were confirmed by IH-NMR and FTIR spectroscopy. The , β-CD-conjugated PEG-PLGA formed stable reverse micelles due to the formation of fl-CD and bovine serum albumin （BSA） inclusion complexation, which could accommodate BSA in the organic solvent with improved encapsulation efficiency. Moreover, we demonstrated a one-step approach to construct macroporous protein-containing films using these reverse micelles. The films with ordered pore arrays were directly prepared from reverse micelles. Interestingly, the protein was totally located in the whole matrix except for the pores.展开更多
Poly(N,N-dimethyl acrylamide)-block-poly(styrene)-block-poly(N,N-dimethyl acrylamide)(PDMAc-bPSt-b-PDMAc)amphiphilic triblock copolymer micro/nano-objects were synthesized through reversible addition-fragmentation cha...Poly(N,N-dimethyl acrylamide)-block-poly(styrene)-block-poly(N,N-dimethyl acrylamide)(PDMAc-bPSt-b-PDMAc)amphiphilic triblock copolymer micro/nano-objects were synthesized through reversible addition-fragmentation chain transfer(RAFT)dispersion polymerization of St mediated with poly(N,Ndimethyl acrylamide)trithiocarbonate(PDMAc-TTC-PDMAc)bi-functional macromolecular RAFT agent.It is found that the morphology of the PDMAc-b-PSt-b-PDMAc copolymer micro/nano-objects like spheres,vesicles and vesicle with hexagonally packed hollow hoops(HHHs)wall can be tuned by changing the solvent composition.In addition,vesicles with two sizes(600 nm,264 nm)and vesicles with HHHs features were also synthesized in high solid content systems(30 wt%and 40 wt%,respectively).Besides,as compared with typical AB diblock copolymers(A is the solvophilic,stabilizer block,and B is the solvophobic block),ABA triblock copolymers tend to form higher order morphologies,such as vesicles,under similar conditions.The finding of this study provides a new and robust approach to prepare block copolymer vesicles and other higher order micelles with special structure via PISA.展开更多
This study aimed at the synthesis of silica particles grafted with better-defined homopolymers and block copolymers by tandem approach.Z-functionalized Sbenzyl S’-(3-trimethoxysilyl)propyltrithiocarbonate(BTPT)was us...This study aimed at the synthesis of silica particles grafted with better-defined homopolymers and block copolymers by tandem approach.Z-functionalized Sbenzyl S’-(3-trimethoxysilyl)propyltrithiocarbonate(BTPT)was used as a couplable RAFT agent to synthesize the target inorganic-organic hybrids.Simultaneous coupling reaction and RAFT process using silica particles and BTPT as raw materials efficiently afforded homopolymers grafted silica,and RAFTsynthesized macro chain transfer agents withω-terminal trimethoxysilane moiety were utilized to mediate graft reaction to prepare silica particles grafted with di-,tri-and tetrablock copolymers comprised of polymer segments such as polystyrene,polyacrylamides and polyacrylates.When the grafted chains had molecular weights ranging between 3920 and 24800 g/mol,the molar grafting ratios,which were dependent on reaction conditions and types and compositions of grafted chains,were estimated to be in the range of 15.2–101μmol/g,and grafted polymers usually had polydispersity indices lower than 1.3,revealing that the grafting process was almost controllable.To the best of our knowledge,this versatile tandem approach is one of the most facile techniques to prepare silica particles grafted with polymeric chains with controlled molecular weight,low polydispersity and precise composition due to its minimal reaction steps,mild conditions,straightforward synthesis and satisfactory controllability.展开更多
基金financially supported by the State Key Program of National Natural Science Foundation of China(U21A20313)the Key Program of Qingyuan Innovation Laboratory(00221003)+2 种基金the“111”Program of Fuzhou Universitythe Natural Science Foundation of Fujian Province(2019J05040)the China Postdoctoral Science Foundation(2022M20739)。
文摘The exploitation of new green polymerization avenues for the effective synthesis of polymers by reversible-deactivation radical polymerization plays a critical role in pursuing the development of polymeric materials.In this work,serials of deep eutectic solvents(DES)with intermolecular-hydrogen-bonding interaction were constructed as catalysts and medium for actuating reversible complexation-mediated polymerization(RCMP)for the first time,yielding methacrylate polymers with high monomer conversion and narrow dispersion molecular weight in both water and oil systems.The mechanism and elementary reaction of RCMP were explored deeply,revealing that the complexation of initiator with DES to generate radicals was a ratecontrolling step and intermolecular-hydrogen-bond was primary factor to influence polymerization rate.Moreover,the insights of density functional theory calculations revealed that negative electrostatic potential ensured nucleophilic capacity.This investigation demonstrated the considerable potential of DES for RCMP,which is anticipated for other polymerization applications as a novel medium mode.
基金supported by the National Science Foundation of China (21833008, 21534004)JLU-STIRT Program at Jilin University
文摘Dynamic self-assembly processes occurring out of thermodynamic equilibrium underlie many forms of adaptive and intelligent behaviors in natural systems.Because of the continuous input of energy,the dynamic self-assembly provides the opportunity for creating structures that are unattainable in equilibrium state.In this paper,we propose a strategy in the dynamic self-assembly of amphiphilic block copolymers regulated by reversible chemical reaction.By time-dependently tuning the reaction direction in the simulations,the amphiphilicity of building block keeps changing periodically.Relying on this dynamic process,we can obtain exotic self-assembled vesicle with surface pores which is otherwise metastable in an equilibrium state.The effects induced by the type of chemical reaction and the reaction period are discussed.Only at short reaction period in suitable reversible reaction,novel self-assembly structure emerges.It is attributed to the competition of reaction and diffusion in the dynamic process,by which the local component of building blocks alters a lot,leading to large local surface tension resulting in the formation of perforated vesicle.In order to predict the assembled structure in a dynamic process,we build up the relationship between component ratio P,the diffusion effect parameter Pdiff and assembled structures.The dynamic self-assembly regulated by chemical reaction holds great promise as a rational strategy to realize exotic functional materials that are not easily obtained in equilibrium.
基金the National Natural Science Foundation of China(Grant 22171055,52222301,and 21971047)the Guangdong Natural Science Foundation for Distinguished Young Scholar(Grant 2022B1515020078)the Science and Technology Program of Guangzhou(Grant SL2023A04J00142).
文摘Reversible addition-fragmentation chain transfer(RAFT)-mediated polymerization-induced self-assembly(PISA)of star block copolymer and linear block copolymer using a binary mixture of a star-like macro-RAFT agent and a linear macro-RAFT agent is reported.With this formulation,star block copolymer and diblock copolymer were formed simultaneously to generate colloidally stable star/linear block copolymer assemblies.Size exclusion chromatography(SEC)analysis confirmed the presence of two types of polymers in the final samples.The molar ratio of the star-like macro-RAFT agent and the linear macro-RAFT agent has a significant impact on the morphology of polymer assemblies.It was found that increasing the amount of star-like macro-RAFT agent facilitated the formation of higher-order morphologies.Additionally,effects of other reaction parameters including the length/number of the arm of the star-like macro-RAFT agent,degree of polymer(DP),monomer concentration on the morphology of star/linear block copolymer assemblies were also investigated.We expect that this work will offer new possibilities for the scalable preparation of polymer assemblies with unique structures and functions.
文摘Reverse addition\|fragmentation chain transfer (RAFT) polymerizatin of MAn with St is reported aiming at the synthesis of a well\|defined alternating copolymer of MAn with St.The results show that the polymers possess predetermined molecular weight and molecular weight distribution as narrow as 1 2. A novel well\|defined block copolymer P(MAn\| alt \|St)\| b \|PSt has also been prepared by the copolymerization of MAn with excess amount of St in molar feed via RAFT process.
基金financially supported by the National Natural Science Foundation of China(Nos.21374079 and 21244004)Program for New Century Excellent Talents in Universities(No.NCET-11-1063)Program for Prominent Young College Teachers of Tianjin Educational Committee
文摘A series of β-cyclodextrin-conjugated 4-arm poly（ethylene glycol）-poly（lactide-co-glycolide） （4-arm PEG-PLGA） copolymers were synthesized by a ring-opening polymerization of D,L-lactide and glycolide using 4-arm PEG as initiator, and then conjugated with mono（6-ethylenediamine-6-deoxy）- β-cyclodextrin （CDen） or ethylenediamino-bridged bis- β-CD （BCDen）. The chemical structures of copolymers were confirmed by IH-NMR and FTIR spectroscopy. The , β-CD-conjugated PEG-PLGA formed stable reverse micelles due to the formation of fl-CD and bovine serum albumin （BSA） inclusion complexation, which could accommodate BSA in the organic solvent with improved encapsulation efficiency. Moreover, we demonstrated a one-step approach to construct macroporous protein-containing films using these reverse micelles. The films with ordered pore arrays were directly prepared from reverse micelles. Interestingly, the protein was totally located in the whole matrix except for the pores.
文摘Poly(N,N-dimethyl acrylamide)-block-poly(styrene)-block-poly(N,N-dimethyl acrylamide)(PDMAc-bPSt-b-PDMAc)amphiphilic triblock copolymer micro/nano-objects were synthesized through reversible addition-fragmentation chain transfer(RAFT)dispersion polymerization of St mediated with poly(N,Ndimethyl acrylamide)trithiocarbonate(PDMAc-TTC-PDMAc)bi-functional macromolecular RAFT agent.It is found that the morphology of the PDMAc-b-PSt-b-PDMAc copolymer micro/nano-objects like spheres,vesicles and vesicle with hexagonally packed hollow hoops(HHHs)wall can be tuned by changing the solvent composition.In addition,vesicles with two sizes(600 nm,264 nm)and vesicles with HHHs features were also synthesized in high solid content systems(30 wt%and 40 wt%,respectively).Besides,as compared with typical AB diblock copolymers(A is the solvophilic,stabilizer block,and B is the solvophobic block),ABA triblock copolymers tend to form higher order morphologies,such as vesicles,under similar conditions.The finding of this study provides a new and robust approach to prepare block copolymer vesicles and other higher order micelles with special structure via PISA.
基金The financial support from the National Natural Science Foundation of China(Grant Nos.20844001,20874067 and 21074081)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions is gratefully acknowledged.
文摘This study aimed at the synthesis of silica particles grafted with better-defined homopolymers and block copolymers by tandem approach.Z-functionalized Sbenzyl S’-(3-trimethoxysilyl)propyltrithiocarbonate(BTPT)was used as a couplable RAFT agent to synthesize the target inorganic-organic hybrids.Simultaneous coupling reaction and RAFT process using silica particles and BTPT as raw materials efficiently afforded homopolymers grafted silica,and RAFTsynthesized macro chain transfer agents withω-terminal trimethoxysilane moiety were utilized to mediate graft reaction to prepare silica particles grafted with di-,tri-and tetrablock copolymers comprised of polymer segments such as polystyrene,polyacrylamides and polyacrylates.When the grafted chains had molecular weights ranging between 3920 and 24800 g/mol,the molar grafting ratios,which were dependent on reaction conditions and types and compositions of grafted chains,were estimated to be in the range of 15.2–101μmol/g,and grafted polymers usually had polydispersity indices lower than 1.3,revealing that the grafting process was almost controllable.To the best of our knowledge,this versatile tandem approach is one of the most facile techniques to prepare silica particles grafted with polymeric chains with controlled molecular weight,low polydispersity and precise composition due to its minimal reaction steps,mild conditions,straightforward synthesis and satisfactory controllability.
