功能材料
功能材料
공능재료
JOURNAL OF FUNCTIONAL MATERIALS
2015年
9期
9036-9040
,共5页
两亲性嵌段共聚物%偶氮苯%光响应性%自组装%光致异构
兩親性嵌段共聚物%偶氮苯%光響應性%自組裝%光緻異構
량친성감단공취물%우담분%광향응성%자조장%광치이구
amphiphilic block copolymers%azobenzene%photo-responsive%self-assembly%photo isomerisation
采用可逆加成-断裂链转移(RAFT)聚合法制备了以苯乙烯-马来酸酐交替共聚物(PSMA)与聚乙二醇甲基丙烯酸酯(MAPEG)组成的共聚物(PS-MA-b-PMAPEG),经4-氨基偶氮苯(4-AAB)修饰得光响应性两亲性嵌段共聚物 P(St-al-Ma/azo-MaIM)-b-PMAPEG.用红外光谱(FT-IR )、核磁共振(1 H NMR)、凝胶渗透色谱(GPC)对其结构进行表征.此共聚物在水中可自组装形成胶束,由透射电子显微镜(TEM)和动态光散射(DLS )表征可知胶束直径约100 nm.用紫外-可见光谱法(UV-Vis)研究胶束溶液的吸光度随光照时间的变化;DLS 和扫描电子显微镜(SEM)观察紫外光和可见光辐射对胶束粒径的影响,结果表明,胶束经365 nm 紫外光照射后,偶氮苯由反式结构转变成顺式结构,粒径增大;再经420 nm 可见光照射,偶氮苯结构又从顺式转变回反式,粒径减小到初始值.
採用可逆加成-斷裂鏈轉移(RAFT)聚閤法製備瞭以苯乙烯-馬來痠酐交替共聚物(PSMA)與聚乙二醇甲基丙烯痠酯(MAPEG)組成的共聚物(PS-MA-b-PMAPEG),經4-氨基偶氮苯(4-AAB)脩飾得光響應性兩親性嵌段共聚物 P(St-al-Ma/azo-MaIM)-b-PMAPEG.用紅外光譜(FT-IR )、覈磁共振(1 H NMR)、凝膠滲透色譜(GPC)對其結構進行錶徵.此共聚物在水中可自組裝形成膠束,由透射電子顯微鏡(TEM)和動態光散射(DLS )錶徵可知膠束直徑約100 nm.用紫外-可見光譜法(UV-Vis)研究膠束溶液的吸光度隨光照時間的變化;DLS 和掃描電子顯微鏡(SEM)觀察紫外光和可見光輻射對膠束粒徑的影響,結果錶明,膠束經365 nm 紫外光照射後,偶氮苯由反式結構轉變成順式結構,粒徑增大;再經420 nm 可見光照射,偶氮苯結構又從順式轉變迴反式,粒徑減小到初始值.
채용가역가성-단렬련전이(RAFT)취합법제비료이분을희-마래산항교체공취물(PSMA)여취을이순갑기병희산지(MAPEG)조성적공취물(PS-MA-b-PMAPEG),경4-안기우담분(4-AAB)수식득광향응성량친성감단공취물 P(St-al-Ma/azo-MaIM)-b-PMAPEG.용홍외광보(FT-IR )、핵자공진(1 H NMR)、응효삼투색보(GPC)대기결구진행표정.차공취물재수중가자조장형성효속,유투사전자현미경(TEM)화동태광산사(DLS )표정가지효속직경약100 nm.용자외-가견광보법(UV-Vis)연구효속용액적흡광도수광조시간적변화;DLS 화소묘전자현미경(SEM)관찰자외광화가견광복사대효속립경적영향,결과표명,효속경365 nm 자외광조사후,우담분유반식결구전변성순식결구,립경증대;재경420 nm 가견광조사,우담분결구우종순식전변회반식,립경감소도초시치.
An amphiphilic block copolymer based on poly(styrene-co-maleic anhydride)-b-poly(single-methoxy-poly(ethylene glycol)methyl acrylate)(PSMA-b-PMAPEG),was synthesized by reversible addition fragmen-tation chain transfer radical (RAFT)polymerization,and was further modified by p-aminoazobenzene to form photo-responsive block copolymer P(St-al-Ma/azo-MaIM)-b-PMAPEG.The block copolymer was characterized by Fourier transform infrared spectroscopy (FT-IR),1 H nuclear magnetic resonance (1 H NMR),and gel per-meation chromatography (GPC).Nanosized micelles were formed by self-assembly when the P (SMA/azo-MaIM)-b-P(MAPEG)was dissolved in water solution.Transmission electron microscopy (TEM)and dynamic light scattering (DLS)measurements showed that the micelles were regularly spherical in shape with an average diameter of about 100 nm.The photo-responsive behavior of the copolymer was studied by UV-Vis spectrosco-py,DLS and scanning electron microscopy (SEM).The UV-Vis spectroscopy indicates that the absorption peak at 360 nm decreased and the peak at 450 nm increased with increasing the irradiation time of 365 nm UV light, and the corresponding absorption peak recovered when the solution continued to be irradiated using 420 nm visi-ble light.The DLS measurements indicated that the size of the micelles increased from about 100 to about 300 nm when they were exposed under 365 nm light,and the micelles’size decreased from about 300 to about 100 nm when the irradiation was changed to 420 nm visible light,and these results were confirmed by SEM measurements.The size change of the micelles under the irradiation with different wavelength was caused by the isomerization of azobenzene which changed from trans-form to cis-form by UV irradiation of 365 nm and recov-ered to trans-form by visible light irradiation of 420 nm.