A β-diketone-bridged chromophore-containing acrylic monomer, 1-(4-dimethylaminophenyl)-4-methyl-4-pentene-1,3-diketone(DMPDK) and its saturated model compound, 1-(4-dimethyl aminophenyl)-1,3-butanedione(DMBDK) were s...A β-diketone-bridged chromophore-containing acrylic monomer, 1-(4-dimethylaminophenyl)-4-methyl-4-pentene-1,3-diketone(DMPDK) and its saturated model compound, 1-(4-dimethyl aminophenyl)-1,3-butanedione(DMBDK) were synthesized and investigated by spectroscopy. It was found that the fluorescence intensity of DMPDK was much lower than that of DMBDK at the same concentration, which indicates that DMPDK, a β-diketone-bridged acrylic monomer having chromophore moiety, also showed fluorescence structural self-quenching effect(SSQE). Photo-induced tautomerization of DMBDK in acetonitrile was studied by means of UV and fluorescence spectroscopy. The results imply that the fluorescence method is capable of monitoring tautomerization of some fluorescent β-diketones.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
Self assembly of an amphiphilic diblock copolymer polysyrene b polyvinylbenzoic acid in ethanol,which is a selective solvent for the polybenzoic acid segment was studied by means of transmission electron microscopy.Th...Self assembly of an amphiphilic diblock copolymer polysyrene b polyvinylbenzoic acid in ethanol,which is a selective solvent for the polybenzoic acid segment was studied by means of transmission electron microscopy.The diblock copolymers can self assemble into nano scale aggregates with polystyrene segment as the core and polyvinylbenzoic acid segment as the corona.The morphology of the aggregates is mainly controlled by the ratio of the two segment of the diblock copolymer.As the content of the ethanol insoluble polystyrene segment increased,the morphology can be changed from spheres to rods.The diameter of the aggregates increases slightly with concentration and decreases with the addition of CoCl 2 salt.展开更多
To avoid the damage to catalytic system in ATRP by the carboxyl groups in vinyl benzoic acid, a well defined poly( p vinyl benzoic acid) was synthesized via ATRP in the tertiary butyl ester form. The ATRP of t butyl p...To avoid the damage to catalytic system in ATRP by the carboxyl groups in vinyl benzoic acid, a well defined poly( p vinyl benzoic acid) was synthesized via ATRP in the tertiary butyl ester form. The ATRP of t butyl p vinyl benzoate ( t BVB) was studied kinetically. The results showed that t BVB can be polymerized in a controlled way by ATRP. It was found that the polymerization rate of t BVB is much faster than that of St, meaning that the electron withdrawing ester group affects the polymerization obviously. Well defined diblock copolymers of St and t BVB were prepared by using bromo terminated PBVBs as macroinitiators via ATRP. After removal of the t butyl group by hydrolysis, well defined amphiphilic diblock copolymers of styrene and p vinyl benzoic acid (PSt b PBVA) were obtained.展开更多
Controlled radical copolymerization including atom transfer radical polymerization(ATRP) and radical reversible addition\|fragmentation chain transfer polymerization(RAFT) of iso \|butyl vinyl ether ( i BVE) with elec...Controlled radical copolymerization including atom transfer radical polymerization(ATRP) and radical reversible addition\|fragmentation chain transfer polymerization(RAFT) of iso \|butyl vinyl ether ( i BVE) with electron\|withdrawing monomers such as maleic anhydride and N substituted maleimides,have been studied.Results show that ATRP of i BVE with electron\|withdrawing monomers does not work well,while the well\|defined copolymers are obtained via RAFT polymerization.The copolymers thus obtained possess alternating structure,predetermined molecular weight and molecular weight distribution as narrow as 1 2～1 4.展开更多
C\-\{60\}\|end\|bonded polystryrenes(PS\|C\-\{60\}\|Br) with narrow molecular weight polydispersity were prepared by atom transfer radical polymerization (ATRP) in good yield.GPC results show that the polydispersities...C\-\{60\}\|end\|bonded polystryrenes(PS\|C\-\{60\}\|Br) with narrow molecular weight polydispersity were prepared by atom transfer radical polymerization (ATRP) in good yield.GPC results show that the polydispersities of these fullerene polymeric derivatives were between 1.1 and 1.3.The brown color of the solution indicates that C\-\{60\} has been bonded into the polymer,which was confirm by UV\|vis.Furthermore,2\|amino\|acetonictrile was used as an IR label to react with PS\|C\-\{60\}\|Br,and the product show the characteristic absorption of CN group at 2369cm\+\{-1\}.These results reinforce the conclusion that C\-\{60\} has been covalently bonded into the polymer.A possible mechanism of the formation of C\-\{60\}\|end\|bonded PSt was deduced tentatively.展开更多
An acrylic monomer bearing carbazole moiety,3 methacrylamido 9 ethylcarbazole (MAECz)was synthesized and polymerized radically.Fluorescence studies showed that at the same chromophore concentration,the fluorescence in...An acrylic monomer bearing carbazole moiety,3 methacrylamido 9 ethylcarbazole (MAECz)was synthesized and polymerized radically.Fluorescence studies showed that at the same chromophore concentration,the fluorescence intensity of the polymer (P(MAECz) was much stronger than that of the monomer.This can be explained by what we termed fluorescence “Structural Self Quenching Effect”(SSQE).The stern volmer constants of P(MAECz) in solution quenched by several electron deficient vinyl monomers were obtained.It was found that the quenching efficiency of the quenchers was relevant to the degree of the electron deficiency.Also,the photopolymerization of acrylonitrile (AN) initiated by MAECz was investigated kinetically and a tentative initiation mechanism was proposed.展开更多
Bismaleimides bearing electron-donating chromophore moieties, A (=)-D (*)-A (=) type monomers, i.e. N,N-bis(4-maleimidophenyl)methylamine (BMIPMA), N,N-bis(4-maleimidophenyl)aniline(BMIPA) and 2,5-bis(4-maleimido phen...Bismaleimides bearing electron-donating chromophore moieties, A (=)-D (*)-A (=) type monomers, i.e. N,N-bis(4-maleimidophenyl)methylamine (BMIPMA), N,N-bis(4-maleimidophenyl)aniline(BMIPA) and 2,5-bis(4-maleimido phenyl)-1,3,4-oxadiazole(BMIPODA) as well as their corresponding saturated model compounds, i.e. N,N-bis(4-succinimidophenyl)methylamine( BSIPMA), N,N-bis(4-succinimidophenyl)aniline(BSIPA) and 2,5-bis(4-succimidophenyl)-1,3,4-oxadiazole (BSIPODA) were synthesized. It was found that the fluorescence quantum yields of A (=)-D (*)-A (=) monomers were always dramatically lower than those of their corresponding saturated model compounds. These A (=)-D (*)-A (=) bismaleimides possess a strong SSQE, which is attributed to an intramolecular charge transfer interaction.展开更多
Bismaleimides bearing electron\|donating chromophore moieties, i.e.N,N \|bis(4\|maleimidophenyl)\|methylamine (BMIPMA),and its saturated model compound N,N\| bis(4\|succinimidophenyl)\|methylamine(BSIPMA) were synthes...Bismaleimides bearing electron\|donating chromophore moieties, i.e.N,N \|bis(4\|maleimidophenyl)\|methylamine (BMIPMA),and its saturated model compound N,N\| bis(4\|succinimidophenyl)\|methylamine(BSIPMA) were synthesized and their absorption and fluorescence behaviors were investigated. It was found that BMIPMA possess a strong fluorescence structural self\|quenching effect (SSQE).There is almost no fluorescence emission observed for BMIPMA,whereas its saturated model compound BSIPMA displays a strong fluorescence emission at the same chromophore concentration.On the basis of the SSQE,a new fluorescence approach was developed to monitor the process of the copolymerization of bismaleimides with diamines,which can directly reflect the consumption of the CC bond of maleimide unit.The results agreed well with that obtained by 1H\|NMR measurement pused.展开更多
文摘A β-diketone-bridged chromophore-containing acrylic monomer, 1-(4-dimethylaminophenyl)-4-methyl-4-pentene-1,3-diketone(DMPDK) and its saturated model compound, 1-(4-dimethyl aminophenyl)-1,3-butanedione(DMBDK) were synthesized and investigated by spectroscopy. It was found that the fluorescence intensity of DMPDK was much lower than that of DMBDK at the same concentration, which indicates that DMPDK, a β-diketone-bridged acrylic monomer having chromophore moiety, also showed fluorescence structural self-quenching effect(SSQE). Photo-induced tautomerization of DMBDK in acetonitrile was studied by means of UV and fluorescence spectroscopy. The results imply that the fluorescence method is capable of monitoring tautomerization of some fluorescent β-diketones.
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.
文摘Self assembly of an amphiphilic diblock copolymer polysyrene b polyvinylbenzoic acid in ethanol,which is a selective solvent for the polybenzoic acid segment was studied by means of transmission electron microscopy.The diblock copolymers can self assemble into nano scale aggregates with polystyrene segment as the core and polyvinylbenzoic acid segment as the corona.The morphology of the aggregates is mainly controlled by the ratio of the two segment of the diblock copolymer.As the content of the ethanol insoluble polystyrene segment increased,the morphology can be changed from spheres to rods.The diameter of the aggregates increases slightly with concentration and decreases with the addition of CoCl 2 salt.
文摘To avoid the damage to catalytic system in ATRP by the carboxyl groups in vinyl benzoic acid, a well defined poly( p vinyl benzoic acid) was synthesized via ATRP in the tertiary butyl ester form. The ATRP of t butyl p vinyl benzoate ( t BVB) was studied kinetically. The results showed that t BVB can be polymerized in a controlled way by ATRP. It was found that the polymerization rate of t BVB is much faster than that of St, meaning that the electron withdrawing ester group affects the polymerization obviously. Well defined diblock copolymers of St and t BVB were prepared by using bromo terminated PBVBs as macroinitiators via ATRP. After removal of the t butyl group by hydrolysis, well defined amphiphilic diblock copolymers of styrene and p vinyl benzoic acid (PSt b PBVA) were obtained.
文摘Controlled radical copolymerization including atom transfer radical polymerization(ATRP) and radical reversible addition\|fragmentation chain transfer polymerization(RAFT) of iso \|butyl vinyl ether ( i BVE) with electron\|withdrawing monomers such as maleic anhydride and N substituted maleimides,have been studied.Results show that ATRP of i BVE with electron\|withdrawing monomers does not work well,while the well\|defined copolymers are obtained via RAFT polymerization.The copolymers thus obtained possess alternating structure,predetermined molecular weight and molecular weight distribution as narrow as 1 2～1 4.
文摘C\-\{60\}\|end\|bonded polystryrenes(PS\|C\-\{60\}\|Br) with narrow molecular weight polydispersity were prepared by atom transfer radical polymerization (ATRP) in good yield.GPC results show that the polydispersities of these fullerene polymeric derivatives were between 1.1 and 1.3.The brown color of the solution indicates that C\-\{60\} has been bonded into the polymer,which was confirm by UV\|vis.Furthermore,2\|amino\|acetonictrile was used as an IR label to react with PS\|C\-\{60\}\|Br,and the product show the characteristic absorption of CN group at 2369cm\+\{-1\}.These results reinforce the conclusion that C\-\{60\} has been covalently bonded into the polymer.A possible mechanism of the formation of C\-\{60\}\|end\|bonded PSt was deduced tentatively.
文摘An acrylic monomer bearing carbazole moiety,3 methacrylamido 9 ethylcarbazole (MAECz)was synthesized and polymerized radically.Fluorescence studies showed that at the same chromophore concentration,the fluorescence intensity of the polymer (P(MAECz) was much stronger than that of the monomer.This can be explained by what we termed fluorescence “Structural Self Quenching Effect”(SSQE).The stern volmer constants of P(MAECz) in solution quenched by several electron deficient vinyl monomers were obtained.It was found that the quenching efficiency of the quenchers was relevant to the degree of the electron deficiency.Also,the photopolymerization of acrylonitrile (AN) initiated by MAECz was investigated kinetically and a tentative initiation mechanism was proposed.
文摘Bismaleimides bearing electron-donating chromophore moieties, A (=)-D (*)-A (=) type monomers, i.e. N,N-bis(4-maleimidophenyl)methylamine (BMIPMA), N,N-bis(4-maleimidophenyl)aniline(BMIPA) and 2,5-bis(4-maleimido phenyl)-1,3,4-oxadiazole(BMIPODA) as well as their corresponding saturated model compounds, i.e. N,N-bis(4-succinimidophenyl)methylamine( BSIPMA), N,N-bis(4-succinimidophenyl)aniline(BSIPA) and 2,5-bis(4-succimidophenyl)-1,3,4-oxadiazole (BSIPODA) were synthesized. It was found that the fluorescence quantum yields of A (=)-D (*)-A (=) monomers were always dramatically lower than those of their corresponding saturated model compounds. These A (=)-D (*)-A (=) bismaleimides possess a strong SSQE, which is attributed to an intramolecular charge transfer interaction.
文摘Bismaleimides bearing electron\|donating chromophore moieties, i.e.N,N \|bis(4\|maleimidophenyl)\|methylamine (BMIPMA),and its saturated model compound N,N\| bis(4\|succinimidophenyl)\|methylamine(BSIPMA) were synthesized and their absorption and fluorescence behaviors were investigated. It was found that BMIPMA possess a strong fluorescence structural self\|quenching effect (SSQE).There is almost no fluorescence emission observed for BMIPMA,whereas its saturated model compound BSIPMA displays a strong fluorescence emission at the same chromophore concentration.On the basis of the SSQE,a new fluorescence approach was developed to monitor the process of the copolymerization of bismaleimides with diamines,which can directly reflect the consumption of the CC bond of maleimide unit.The results agreed well with that obtained by 1H\|NMR measurement pused.
