【作者】 宋冰冰；

【导师】 王柯敏；

【作者基本信息】 湖南大学 ， 分析化学， 2010， 硕士

【摘要】 功能化的环境响应型纳米通道因其在智能分离、化学生物传感、药物控制释放等领域的重要作用及广阔的应用前景而受到日益广泛的关注。本文以多孔性的聚碳酸酯膜为研究对象,采用不同的修饰方法对其进行了功能化修饰,进而考察了所制备的各种功能化纳米通道复合膜的性质及其差异,具体开展了以下几个方面工作：1.采用化学沉积法镀金,制备了表面及通道内都沉积了金的纳米通道膜。通过化学交联的方法将聚N-异丙基丙烯酰胺(PNIPAm)修饰在这种金纳米通道膜上,构造了一种温度敏感纳米通道复合膜。借助全内反射荧光显微成像技术,考察了这种膜的温度敏感性和PNIPAm修饰密度差异对其渗透性的影响。结果表明,膜的渗透性随温度的变化因PNIPAm修饰密度差异而截然相反。修饰密度较低时,聚合物的伸展与收缩所引起的纳米通道尺寸变化占主导地位,环境温度高于临界溶液温度(LCST)时膜的渗透性比较大；而修饰密度较高时,则是膜的亲疏水效应在起主导作用,环境温度低于LCST时膜的渗透性比较大。以阿霉素为药物模型,考察了其在不同条件下的渗透性,结果与前述机理相符。说明这种温度敏感型纳米通道膜有望用于实际的药物控制释放体系,在生命活动模拟、纳米仿生等方面有着潜在的应用价值。2.采用磁控溅射法镀金,得到了仅单面覆盖金的纳米通道膜。将PNIPAm修饰在这种膜上,考察了不同修饰密度情况下的渗透性。结果表明,无论PNIPAm的修饰密度如何,都是环境温度高于LCST时纳米通道膜的渗透性大。这是因为这种膜的通道内没有修饰上PNIPAm,膜的渗透性不受聚合物的亲疏水性主导,而主要取决于表面纳米通道的暴露程度。这种新型的温敏纳米通道膜有望用于微阀门的制备、药物可控释放等领域。3.借助静电吸附作用,采用真空抽滤的方法先将聚烯丙基胺盐酸盐(PAH)修饰在纳米通道膜上,然后修饰PNIPAm,获得了一种无需镀金的新型温度敏感纳米通道膜。利用扫描电镜、衰减全反射红外光谱及视频接触角仪对其修饰结果及其温敏性进行了表征,采用全内反射荧光显微成像技术考察了温度对渗透性的影响。结果表明,这是一种简便、经济的制备温敏型纳米通道膜的方法,这种方法制得的膜具有显著的温敏性和良好的可逆性。更多还原

【Abstract】 Functional stimulus responsive nanopore membranes have attracted great attention because of their comprehensive applications including smart separation, chemo/bio sensing and controlled drug release. In this thesis, nanoporous polycarbonate membranes were functionally modified with different methods, and then the properties and differences of these functional temperature responsive membranes were investigated. The research works of this dissertation are summarized as follows:1. Nanopore membranes with gold along the porewalls and surface were prepared by chemic aggradation, and then poly(N-isopropylacrylamide) (PNIPAm) brushes were grafted onto these gold coated nanoporous track-etched polycarbonate membranes. The permeabilities of the resulting pore-filled membranes were determined by total internal reflection fluorescence microscopy. And the influence of different grafting yield of PNIPAm were also investigated. The results showed that, the change of permeability related to the temperature is distinct at different grafting yield. At low grafting yield, the response of permeability to environmental temperature is due to the change of effective membrane pore size induced by the conformation (expand or shrink) change of the grafted PNIPAm chains, so the permeability of thermoresponsive membranes was higher at temprature above the lower critical solution temperature (LCST); In contrast, at high grafting yield, the response of permeability to environmental temperature is due to the hydrophilic or hydrophobic change of the grafted PNIPAm chains.The permeability of thermoresponsive membranes was higher at temperature below the LCST. A drug permeation model was proposed using doxorubicin as a probe, and the results were consistent with the above. Therefore, this kind of controllable thermoresponsive membrane can be applied in practical controlled drug release, and may have a unique potential application in the field of life process simulation and so on.2. Nanopore membranes with single side gold coated were prepared by vacuum sputter coating, which is a relatively simple method. Temperature responsive nanopore membranes were prepared by modifying the resulting membranes with PNIPAm. The thermally switchable transport properties of the PNIPAm modified membranes with different grafting yield were also investigated. The results confirm that the permeability was higher at temperature above the LCST both at low and high grafting yield. Because the pore walls of these nanoporous membranes were not grafted with PNIP Am and the permeability was dominated by the surface pore coverage rather than the hydrophilic or hydrophobic property of polymer brushes. Therefore, this research developed a new type of temperature responsive nanopore membranes, which may be applied to micro-valves and controlled drug release.3. A novel kind of temperature responsive nanopore membranes without gold coating were obtained through modifying membranes with PNIPAm in terms of vacuum filtration. This method based on polyallylamine hydrochloride (PAH) electrostatic interaction with nanoporous track-etched polycarbonate membranes. Field emission scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, and drop shape analyzer were used to characterize the chemical composition, surface morphologies and thermoresponsive properties of the modified membranes. In addition, the permeabilities of the resulting membranes were investigated by total internal reflection fluorescence microscopy. The results showed that this is an economical, simple and convenient method to construct temperature responsive nanopore membrane with notable thermoresponsive property and favorable reversibility.更多还原