有机纳米粒子杂化水凝胶的制备及其性能研究

发布时间：2018-07-17 06:39

【摘要】：水凝胶是一种特殊的软湿性材料,具有三维网络结构,能够吸收大量的水,可以溶胀却不溶解,具有超强的保水性,以及生物相容性,因此在农业生产,医学研究等领域具有广泛的应用。但由于传统水凝胶本身的性能较差,特别是机械性能,因此使水凝胶的应用在多方面受到了很多限制。通常改善水凝胶的性能的方法有许多种,例如:双网络水凝胶、拓扑结构水凝胶、疏水缔合水凝胶等。此外,纳米粒子水凝胶也是一种较好的改善水凝胶性质的方法,将纳米粒子加入水凝胶基体可以制备杂化水凝胶,同时具有较好的力学性能。纳米微球的制备方法简单,粒子尺寸和分布易调控且表面可进行功能化修饰,能够赋予水凝胶特殊的官能团性质。将表面功能化的有机纳米粒子填加到水凝胶网络中可以制备具有特殊功能和较好力学性能的杂化水凝胶。本文首先制备了表面带有大量负电荷的有机纳米微球,再将其与水溶性单体混合均匀制备了有机纳米微球复合水凝胶并对性能进行了测试。主要内容包括三部分。第一,为制备具有高电荷密度的苯乙烯纳米粒子微球,选用苯乙烯(St)、苯乙烯磺酸钠(NaSS)共同作为反应单体,通过无皂乳液聚合,制备了表面带有高电荷密度,粒径大小约100nm左右的,表面带负电的单分散聚苯乙烯纳米微球(n-PS),并利用傅里叶变换红外光谱测量仪(FT-IR)、激光粒度仪(DLS)、透射电子显微镜(TEM)对微球进行了表征,同时使用电导率滴定仪对微球表面电荷进行测试,测得微球表面电荷为11.046μC/cm2。第二,将上步中制备的n-PS纳米微球以一定比例加入含有引发剂和交联剂的丙烯酰胺(AAm)水溶液中制备了PAAm/n-PS杂化水凝胶。与纯化学交联PAAm水凝胶相比,杂化水凝胶的力学性能稍有提高。含有16%微球的杂化水凝胶的拉伸强度增加了200%,伸长率增加了100%,溶胀实验和往复拉伸实验证明了PAAm链和n-PS之间存在相互作用。第三,在上述杂化水凝胶体系中引入阳离子单体甲基丙烯酰氧氧乙基三甲基氯化铵(DMC),制备了P(AAm-DMC)/n-PS杂化水凝胶。水凝胶的力学性能明显提高。与纯化学交联水凝胶P(AAm-DMC)相比,P(AAm-DMC)/n-PS杂化水凝胶的拉伸性能和初始模量都明显提高。拉伸强度增加了约800%。溶胀实验显示杂化水凝胶的出现明显的去溶胀现象,这和流变实验共同证明了P(AAm-DMC)/n-PS水凝胶存在n-PS微球与DMC链端的正负电荷相互吸引的作用。
[Abstract]:Hydrogels are a special kind of soft wet material, which has a three-dimensional network structure, can absorb a large amount of water, can be swelled but not dissolved, has super water retention, and biocompatibility, so in agricultural production, Medical research and other fields have a wide range of applications. However, due to the poor performance of traditional hydrogels, especially the mechanical properties, the application of hydrogels is limited in many aspects. There are many methods to improve the properties of hydrogels, such as double network hydrogels, topological hydrogels, hydrophobically associating hydrogels and so on. In addition, nano-particle hydrogel is also a good method to improve hydrogel properties. Adding nano-particles to hydrogel matrix can prepare hybrid hydrogels and have good mechanical properties. The preparation method of nanocrystalline microspheres is simple, the particle size and distribution are easy to control and the surface can be functionalized, which can give the hydrogel special functional group properties. Hybrid hydrogels with special functions and better mechanical properties can be prepared by adding surface functionalized organic nanoparticles to hydrogel networks. In this paper, the organic nanospheres with a large amount of negative charge on the surface were prepared firstly, and then the organic nanospheres were mixed with the water-soluble monomers to prepare the organic nano-spheres composite hydrogels and their properties were tested. The main content includes three parts. Firstly, in order to prepare styrene nanoparticles with high charge density, styrene (St) and sodium styrenesulfonate (NaSS) were used as reactive monomers, which were prepared by soap-free emulsion polymerization. Monodisperse polystyrene nanospheres (n-PS) with about 100nm particle size were characterized by Fourier transform infrared spectrometer (FT-IR), laser particle size analyzer and transmission electron microscope (TEM). At the same time, the surface charge of the microspheres was measured by using the conductivity titrator. The surface charge of the microspheres was measured to be 11.046 渭 C / cm ~ 2. Secondly, PAAM / n-PS hybrid hydrogels were prepared by adding n-PS nanospheres into acrylamide (AAm) aqueous solution containing initiator and crosslinking agent in a certain proportion. Compared with pure chemically crosslinked PAAm hydrogels, the mechanical properties of hybrid hydrogels were slightly improved. The tensile strength and elongation of hybrid hydrogels containing 16% microspheres increased by 200 and 100% respectively. The interaction between PAAm chain and n-PS was proved by swelling test and reciprocating tensile test. Thirdly, P (AAm-DMC) / n-PS hybrid hydrogels were prepared by introducing the cationic monomer methacryloxylethyl trimethylammonium chloride (DMC) into the hybrid hydrogel system. The mechanical properties of hydrogels were improved obviously. Compared with pure chemical crosslinked hydrogels P (AAm-DMC) / n-PS hybrid hydrogels, the tensile properties and initial modulus of n-PS hybrid hydrogels were significantly improved. The tensile strength increased by about 800. Swelling experiments show that the hybrid hydrogels have obvious deswelling phenomenon, which, together with rheological experiments, proves that P (AAm-DMC) / n-PS hydrogels attract the positive and negative charges of n-PS microspheres to DMC chains.
【学位授予单位】：长春工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O648.17

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