刺激响应型聚丙烯酸类疏水缔合水凝胶

发布时间：2018-12-14 06:38

【摘要】：水凝胶以自己独特的优势越来越吸引人们的注意。由于其含有大量的水赋予了水凝胶超高的弹性,在许多领域都充当了重要的角色,包括组织工程、生物医学和各类传感器等领域。而在某些特殊领域中,要求水凝胶具备一定的力学性质或者敏感性,于是学者们开始专注于研究并探索基于各种增韧机理的强韧型水凝胶和响应于不同刺激的刺激响应型水凝胶,并取得了一定的成绩。迄今为止,有关强韧型水凝胶的文献报道有很多,大多数是基于能够产生有效的能量耗散,使得水凝胶在形变时不易破碎或者断裂从而拥有更高的强度或韧性。于是产生了很多的增韧机理,包括疏水缔合相互作用、氢键作用、偶极-偶极相互作用,金属络合作用,双网络和大分子微球等。其中疏水缔合常常引起了人们的极大兴趣。本文利用了疏水缔合增韧机理成功制备了具有一定力学性质的韧性水凝胶。该水凝胶是在体系内引入疏水基团,在表面活性剂的存在下,由于疏水作用自组装成胶束充当动态交联点而制备得到。在形变过程中,胶束内部缠结的疏水链段将会发生解缠或者滑移,耗散大量的能量,从而使得疏水缔合水凝胶具有良好的力学性质。然而在一些领域又需要敏感型水凝胶,要求水凝胶在一定刺激下发生一定的变化。大部分学者研究并发表了许多有关溶胶-凝胶转变的刺激响应型水凝胶。这些水凝胶在药物控释、药物运输载体等方面有着良好的应用和潜在的应用前景。但是这类水凝胶的力学性质普遍比较差,在一些既要求力学性质又要求刺激响应性的应用方面将会大大受到限制。所以,制备具有良好的力学性质并具有刺激响应性的水凝胶是很有意义的。本文基于疏水缔合水凝胶,使用环境相响应型的丙烯酸材料成功制备并得到具有良好力学性质并可调控力学性质的刺激响应型水凝胶:一种是pH响应型的机械性能可调控的刺激响应型疏水缔合水凝胶,可以通过调节pH转换金属络合、氢键和疏水缔合之间的相互作用进而调控水凝胶的机械性能;一种是光响应型的机械性能可调控的刺激响应型疏水缔合水凝胶,以柠檬酸分子作为光响应材料,以Fe(III)和Fe(II)之间的氧化还原为驱动力,进而调控水凝胶的机械性能。我们预计该种水凝胶将会为设计各种水凝胶提供更多的可能性,并在一定程度上大大扩大水凝胶的应用范围。
[Abstract]:Hydrogels are attracting more and more attention because of their unique advantages. Because it contains a lot of water to endow the hydrogel with super elasticity, it plays an important role in many fields, including tissue engineering, biomedicine and various sensors. In some special fields, hydrogels are required to have certain mechanical properties or sensitivity. Therefore, the researchers began to study and explore the toughening hydrogels based on various toughening mechanisms and the stimulus-responsive hydrogels responsive to different stimuli, and obtained some achievements. Up to now, there have been a lot of reports about the strong and tough hydrogels, most of which are based on the ability to generate effective energy dissipation, which makes the hydrogels difficult to break or fracture during deformation and thus have higher strength or toughness. There are many toughening mechanisms, including hydrophobic association interaction, hydrogen bond interaction, dipole-dipole interaction, metal complexation, double networks and macromolecular microspheres. Among them hydrophobic association often aroused people's great interest. In this paper, the hydrophobic association toughening mechanism was used to successfully prepare the ductile hydrogels with certain mechanical properties. The hydrogel was prepared by introducing hydrophobic groups into the system and using hydrophobic self-assembly micelles to act as dynamic crosslinking points in the presence of surfactants. In the process of deformation, the hydrophobic segments of the entangled micelles will be unwrapped or slip, and a large amount of energy will be dissipated, thus making the hydrophobic associating hydrogels have good mechanical properties. However, in some fields, sensitive hydrogels are required to change under certain stimuli. Most scholars have studied and published many stimuli-responsive hydrogels related to sol-gel transition. These hydrogels have good applications and potential applications in drug controlled release and drug transport carriers. However, the mechanical properties of these hydrogels are generally poor, and some applications which require both mechanical properties and stimuli responsiveness will be greatly restricted. Therefore, the preparation of hydrogels with good mechanical properties and stimulus response is of great significance. Based on hydrophobically associating hydrogels, The stimulus-responsive hydrogels with good mechanical properties and adjustable mechanical properties were successfully prepared using environment-responsive acrylic materials. One was the pH responsive hydrophobic hydrophobically associating hydrophobic hydrogel with adjustable mechanical properties. The mechanical properties of hydrogels can be regulated by adjusting the interaction between metal complexes, hydrogen bonds and hydrophobic association of pH. One is a kind of photo-responsive hydrophobically associating hydrogel with adjustable mechanical properties. The citric acid molecule is used as the photoresponse material and the redox between Fe (III) and Fe (II) is the driving force. Furthermore, the mechanical properties of hydrogels are regulated. We expect that this kind of hydrogel will provide more possibilities for the design of various hydrogels and greatly expand the application of hydrogels to a certain extent.
【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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