中文摘要：

聚N-异丙基丙烯酰胺（PNIPAAm）在临界温度（32℃）附近会发生敏锐的相变，导致其体积和表面亲疏水性的突变．利用这种由温度刺激引起的体积变化，可以控制微通道内微流体的运动状态．本文以2-羟基-2-甲基-1-苯基丙酮为引发剂，水-乙醇混合体系为溶剂，在玻璃芯片通道内局部区域以紫外光诱导聚合PNIPAAm整体柱塞，制备温控微阀．系统地考察了聚合条件对该阀的形态和性能的影响．在此基础上，建立了一个芯片上的集成化单温控阀流动注射分析模型，利用镁离子与荧光探针O，O＇-二羟基偶氮苯的螯合荧光反应，表征温控微阀的控流效果．结果表明，所制作的微阀温控效果良好，在微流控领域有应用前景．

英文摘要：

Poly（N-isopropylaerylamide） （PNIPAAm） undergoes a rapid phase transition at its lower critical solution temperature（32 ℃ ） , leading to sharp changes in its volume and surface wettability. The thermally responsive volume change behavior of the PNIPAAm can be used to manipulate the microfluids in microchannels. In the present work, PNIPAAm monolithic plugs, serving as the thermally actuated microfluidic valve, were prepared by photoinitiated polymerization within the channels of a glass chip. Photo-polymerization of the N-isopropylacrylamide monomer in water/ethanol was carried out using 2-hydroxy-2-methyl propiophenone as the photo-initiator. The polymerization conditions for the thermally actuated microfluidic valve and its fluid-manipulating behavior were systematically investigated. Based on these investigations, a protocol of on-chip-integrated micro-flow injection（μFIA） system equipped with a single thermally actuated microfluidic valve was established. The analytical performance of the μFIA system was demonstrated with the chelating reaction between the magnesium（ Ⅱ ） and the fluorescent agent O, O＇-dihydroxyazobenzene. Experimental results show that the mirofluidic valve behaved well for the flow control and was promising in the field of mierofluidies.