常压等离子体射流放电及聚合温敏高分子材料的研究

发布时间：2018-05-25 02:45

本文选题：等离子体射流 + 聚合　；参考：《东华大学》2015年硕士论文

【摘要】：大气压等离子体放电多是在间隙较小的平行板电极间进行，限制了处理材料的几何形状尺寸，放电的稳定性也容易受到影响。大气压等离子体射流（Atmospheric Pressure Plasma Jet）放电区域与工作区域相分离，互不影响，可以处理形状较为复杂的材料，材料的表面处理均匀性好，同时放电气体的温度较低，因此在材料表面改性、薄膜沉积、生物医学等方面得到大规模的应用。本文设计了单电极大气压沿面介质阻挡放电Ar等离子体射流装置，系统的研究了不同的实验条件（外加电压，气体流速，放电间隙等）对放电特性的影响。通过发射光谱，分析了等离子体射流中存在的主要基团。选用了波长分别为696.12nm、706.34nm、714.93nm的谱线，通过波尔兹曼作图法，线性拟合求得电子激发温度。此外，，通过光纤传感器测量了管外气体的温度。聚（N-异丙基丙烯酰胺）（PNIPAm）分子内同时含有亲水的酰胺基和疏水的异丙基，因此具有良好的温敏特性。PNIPAm在水溶液中有较低的临界溶解温度（Lower Critical Solution Temperature，LCST）：当溶液温度低于LCST时，聚合物具有良好的溶解性，溶液呈透明状；当温度升高到LCST以上时，聚合物会从水溶液中相分离，溶液变浑浊。且整个相变过程具有可逆性。这种独特的温敏性相转变功能，使其在药物缓释、物质分离、环境监测、温敏开关等方面具有广泛的应用前景。本文首次对不同浓度的NIPAm单体水溶液的温敏性进行了研究，结果表明高浓度的NIPAm溶液也具有一定的温敏性。本文以不同浓度的N-异丙基丙烯酰胺（NIPAm）单体为反应物，在常压下，通过气体（Ar）携带单体溶液的方法，首次采用等离子体射流在基底表面聚合一系列不同单体浓度的PNIPAm聚合物，使用扫描电子显微镜(SEM)、红外光谱、水接触角表征了产物的结构与性能。聚合物的傅里叶红外光谱(FT-IR)显示存在C=O伸缩振动峰和N-H弯曲振动峰；SEM和接触角温敏变化等的分析结果，表明大气压等离子体射流成功聚合得到了PNIPAm。
[Abstract]:The atmospheric pressure plasma discharge is mostly carried out between parallel plate electrodes with small gap, which limits the geometry and size of the treated materials, and the stability of the discharge is easily affected. Atmospheric plasma jet can separate the discharge area of Atmospheric Pressure Plasma Jet) from the working area. It can be used to deal with materials with more complicated shape. The surface treatment uniformity of the materials is good, and the temperature of the discharge gas is low. Therefore, it is widely used in material surface modification, film deposition, biomedicine and so on. An ar plasma jet device for dielectric barrier discharge (DBD) with a single electrode at atmospheric pressure is designed in this paper. The effects of different experimental conditions (applied voltage, gas velocity, discharge gap, etc.) on the discharge characteristics are systematically studied. The main groups in plasma jet were analyzed by emission spectrum. The electron excitation temperature was obtained by linear fitting with a wavelength of 696.12 nm ~ 706.34 nm ~ 714.93 nm. In addition, the temperature of gas outside the tube was measured by optical fiber sensor. Poly (N- isopropyl acrylamide) contains hydrophilic amide group and hydrophobic isopropyl group, so it has good temperature sensitivity. PNIPAm has lower critical solution temperature and lower Critical Solution temperature when the solution temperature is lower than LCST. When the temperature is higher than LCST, the polymer will be separated from the aqueous solution and the solution will become turbid. The whole phase transition process is reversible. This unique function of phase transition of temperature sensitivity makes it have a wide application prospect in drug release, substance separation, environmental monitoring, temperature sensitive switch and so on. The temperature sensitivity of NIPAm monomer aqueous solution with different concentrations was studied for the first time in this paper. The results show that the high concentration of NIPAm solution also has a certain temperature sensitivity. In this paper, a series of PNIPAm polymers with different monomer concentrations were firstly polymerized by plasma jet on the substrate surface using different concentrations of N-isopropyl acrylamide as reactants. The structure and properties of the products were characterized by SEM, IR and water contact angle. Fourier transform infrared spectroscopy (FT-IR) of the polymer shows the existence of Cno stretching vibration peak and N-H bending vibration peak SEM and temperature sensitive change of contact angle. It is shown that PNIPAms have been successfully polymerized by atmospheric pressure plasma jet.
【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB324

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