SYNTHESIS OF N-ISOPROYLACRYLAMIDE COPOLYMER MICROGELS SENSITIVE TO LEAD IONS
SYNTHESIS OF N-ISOPROYLACRYLAMIDE COPOLYMER MICROGELS SENSITIVE TO LEAD IONS
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铅离子敏感N-异丙烯酰胺共聚物微凝胶的合成
DOI：
10.3724/sp.j.1105.2010.09385
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
Zhang Yongjun
中科院分区：
文献类型：
--
作者：
Luo Qiaofang;Guan Ying;Zhang Yongjun
聚通过对母体聚乙烯进行改性，合成了带有苯并18冠6功能基团的N-异丙基丙烯酰胺微凝胶在EDC催化下，合成了4 ′-氨基苯并18-冠-6（N-异丙基丙烯酰胺-丙烯酸）微凝胶，通过IR和NMR证实了功能基团的引入，所得微凝胶仍具有温敏性，但体积相变温度从30℃移至42℃，微凝胶的溶胀度也随之增大，用动态光散射法研究了Na +和Pb ~（2+）对微凝胶粒径的影响，在不控制离子强度的情况下，微凝胶粒径随[NaCl]的增大而减小，随[Pb（NO3）2]的增大先减小后增大，当离子强度一定时，[Na + ]的增大对微凝胶粒径影响不大，而[Pb 2 + ]的增大使微凝胶粒径显著增大，在此情况下，由于冠醚对18-冠-6的亲合力很高，Pb ~（2+）与冠醚的结合进一步增加了其亲水性，使微凝胶溶胀程度增大，但Na ~+与18-冠-6的结合常数较小，光散射结果也表明微凝胶的粒径分布较窄，这种单分散的铅敏微凝胶可用于制备新型的铅敏传感器。
Poly(N-isopropylacrylamide) microgel with functional benzo-18-crown-6 group was synthesized by modifying a parent poly(N-isopropylacrylamide-co-acrylic acid) microgel with 4'-aminobenzo18-crown-6 under EDC catalysis.The introduction of the functional groups was confirmed by IR and NMR.The resultant microgel is still thermosensitive,but the volume phase transition temperature shifts from 30℃ to 42℃.The swelling degree of the microgels increases too,indicating the 4'-acrylamidobenzo-18-crown-6 monomer acts as an hydrophilic one.The effects of Na + and Pb2 + on the microgel size were studied by dynamic light scattering.When ionic strength is not controlled,the microgel size decreases with increasing [NaCl],but first decreases followed by increasing with increasing [Pb(NO3)2].When ionic strength is kept constant,increasing [Na + ] has little effect on microgel size.In contrast,microgel size expands significantly with increasing [Pb2 + ].In this case,the effect of ionic strength was avoided.Because of its high affinity to 18-crown-6,the binding of Pb2 + with crown ether further increases its hydrophilicity,so the microgels swell to a larger extent.However the binding constant between Na + and 18-crown-6 is small,therefore it induces little swelling of the microgel particles.The light scattering results also show a narrow size distribution of the microgels.The monodisperse,lead-sensitive microgel may find application for the fabrication of new lead sensors.