《厦门大学学报（自然科学版）》

以温度响应性N-异丙基丙烯酰胺(NIPAM)和pH响应性丙烯酸(AA)作为功能单体,与甲基丙烯酰氧丙基七异丁基笼形倍半硅氧烷(MAPOSS)通过可逆加成-断裂转移聚合法(reversible addition-fragmentation chain transfer polymerization,RAFT)共聚,合成具有双重响应性的多面体齐聚倍半硅氧烷(polyhedral oligomeric silsesquioxane,POSS)基嵌段共聚物PMAPOSS-b-(PNIPAM-co-PAA); 采用动态光散射(dynamic light scattering,DLS)、紫外-可见吸收光谱和荧光光谱等测试手段研究了POSS基嵌段共聚物的温度与pH响应行为.结果表明:嵌段共聚物胶束在外部环境pH变小时,粒径明显增大,而在较高pH下,胶束粒径保持稳定; 当外部环境温度小于低临界溶解温度(lower critical solution temperature,LCST)时,嵌段共聚物胶束粒径较大,当温度升高到LCST及以上时,嵌段共聚物胶束粒径变小; 对于包芘共聚物胶束,在酸性条件下芘能较快释放,且释放速度与疏水链段长短有关,而当包芘共聚物胶束所处环境温度高于LCST时也会导致芘的释放.

POSS-based block copolymers,PMAPOSS-b-(PNIPAM-co-PAA),with double reactivity were prepared via reversible addition-fragmentation chain transfer polymerization(RAFT)using methacrylate isobutyl polyhedral oligomericsilsesquioxane(MAPOSS),and temperature-responsive N-isopropyl acrylamide(NIPAM)and pH-responsive acrylic acid(AA)as functional monomers.And dynamic light scattering(DLS),UV-vis and fluorescence spectroscopies were used to study the temperature- and pH-responsive behaviors of POSS-based block copolymers.The results showed that when the pH was small,the particle size increased obviously,while at a higher pH,the micelle size was stable.When the temperature was lower than lower critical solution temperature(LCST),the PNIPAM segment was stretched and the particle size of the block copolymer micelle was larger.When the temperature was higher than LCST,the particle size of the block copolymer micelle became smaller.Under the acidic condition,pyrene in pyrene-copolymer micelles could be released in a very short time,and the release rate was related to the hydrophobic chain length.When the environmental temperature of pyrene-copolymer micelles was higher than LCST,pyrene could also be released.

引言
1 实验部分
2 结果与讨论
3 结论

图1 嵌段共聚物的合成<br/>Fig.1 Synthesis of block copolymers

图1 嵌段共聚物的合成
Fig.1 Synthesis of block copolymers

图2 PMAPOSS(A)、PMAPOSS-b-(PNIPAM-co-PtBA)(B)和PMAPOSS-b-(PNIPAM-co-PAA)(C)的1H-NMR谱图<br/>Fig.2 1H-NMR spectra of PMAPOSS(A),PMAPOSS-b-(PNIPAM-co-PtBA)(B)and PMAPOSS-b-(PNIPAM-co-PAA)(C)

图2 PMAPOSS(A)、PMAPOSS-b-(PNIPAM-co-PtBA)(B)和PMAPOSS-b-(PNIPAM-co-PAA)(C)的1H-NMR谱图
Fig.2 1H-NMR spectra of PMAPOSS(A),PMAPOSS-b-(PNIPAM-co-PtBA)(B)and PMAPOSS-b-(PNIPAM-co-PAA)(C)

图3 PMAPOSS,PMAPOSS-b-(PNIPAM-co-PtBA)和PMAPOSS-b-(PNIPAM-co-PAA)的FT-IR谱图<br/>Fig.3 FT-IR spectra of PMAPOSS,PMAPOSS-b-(PNIPAM-co-PtBA)and PMAPOSS-b-(PNIPAM-co-PAA)

图3 PMAPOSS,PMAPOSS-b-(PNIPAM-co-PtBA)和PMAPOSS-b-(PNIPAM-co-PAA)的FT-IR谱图
Fig.3 FT-IR spectra of PMAPOSS,PMAPOSS-b-(PNIPAM-co-PtBA)and PMAPOSS-b-(PNIPAM-co-PAA)

表1 嵌段共聚物的合成及水解结果<br/>Tab.1 Synthesis and hydrolytic results of block copolymers

表1 嵌段共聚物的合成及水解结果
Tab.1 Synthesis and hydrolytic results of block copolymers

图4 Ba-10、Ba-15和Ba-20的I3/I1值与溶液浓度对数的关系<br/>Fig.4 Relation between I3/I1 and lg c of Ba-10,Ba-15 and Ba-20

图4 Ba-10、Ba-15和Ba-20的I3/I1值与溶液浓度对数的关系
Fig.4 Relation between I3/I1 and lg c of Ba-10,Ba-15 and Ba-20

图5 Ba-20胶束的TEM图(A～C)和Ba-10,Ba-15,Ba-20胶束的DLS结果(D)<br/>Fig.5 TEM images of Ba-20 micelle(A-C),and DLS results of Ba-10,Ba-15,Ba-20 micelles(D)

图5 Ba-20胶束的TEM图(A～C)和Ba-10,Ba-15,Ba-20胶束的DLS结果(D)
Fig.5 TEM images of Ba-20 micelle(A-C),and DLS results of Ba-10,Ba-15,Ba-20 micelles(D)

图6 嵌段共聚物胶束的粒径(A)和溶液透光率(B)随pH的变化曲线<br/>Fig.6 Variation curves of block copolymer micelle size(A)and transmittance of block copolymer micelles solution(B)with pH

图6 嵌段共聚物胶束的粒径(A)和溶液透光率(B)随pH的变化曲线
Fig.6 Variation curves of block copolymer micelle size(A)and transmittance of block copolymer micelles solution(B)with pH

图7 嵌段共聚物胶束的Zeta电位随pH(A)及温度(B)的变化曲线<br/>Fig.7 Variation curves of Zeta potential of block copolymer micelles with pH(A)and temperature(B)

图7 嵌段共聚物胶束的Zeta电位随pH(A)及温度(B)的变化曲线
Fig.7 Variation curves of Zeta potential of block copolymer micelles with pH(A)and temperature(B)

图8 不同pH下包芘共聚物胶束对芘的释放比例随时间的变化曲线<br/>Fig.8 Variation curves of pyrene release percentage of pyrene-copolymer micelles with time under different pH

图8 不同pH下包芘共聚物胶束对芘的释放比例随时间的变化曲线
Fig.8 Variation curves of pyrene release percentage of pyrene-copolymer micelles with time under different pH

图9 嵌段共聚物胶束粒径随温度的变化曲线<br/>Fig.9 Variation curves of block copolymer micelle size with temperature

图9 嵌段共聚物胶束粒径随温度的变化曲线
Fig.9 Variation curves of block copolymer micelle size with temperature

图10 不同温度下包芘共聚物胶束对芘的释放比例随时间的变化曲线<br/>Fig.10 Variation curves of pyrene release percentage of pyrene-copolymer micells with time at different temperature

图10 不同温度下包芘共聚物胶束对芘的释放比例随时间的变化曲线
Fig.10 Variation curves of pyrene release percentage of pyrene-copolymer micells with time at different temperature

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备注

引言

1 实验部分

2 结果与讨论

3 结论

学报简介

备注

引言

1 实验部分

2 结果与讨论

3 结 论

学报简介

3 结论