基于酰肼和偶氮苯基团有机凝胶的多重响应性研究

发布时间：2018-02-14 18:59

本文关键词： 凝胶偶氮苯酰肼光响应性阴离子响应　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：小分子有机凝胶是一种小分子凝胶因子溶解于溶剂中,通过分子间氢键作用,π-π相互作用,范德华力等非共价键相互作用相互聚集缠绕形成纤维网络结构,从而束缚溶剂形成的自组装软材料。凝胶因子的分子结构对有机凝胶的凝胶性能及刺激响应性有很大的影响。因此对凝胶因子合理的设计、修饰能极大的提高材料的功能性,比如在分子结构中引入对外界光、电、声、离子、酸碱、温度等刺激具有响应的官能团,从而实现有机凝胶对外界的刺激响应性能。基于此,我们选取了基于酰肼基团(酰肼基团含有丰富的氢键)的两类偶氮苯(偶氮苯基团是光响应基团)衍生物Dn、En,研究了它们的有机凝胶性及其凝胶的多重响应性。主要研究内容如下:1、研究了含有不同末端烷基链长度的Dn(n=7、8、10)的有机凝胶性和光响应性。D7只能在环己烷中形成有机凝胶,D8可以在1,2-二氯乙烷和环己烷中形成凝胶,D10在1,2-二氯乙烷、环己烷和二甲基亚砜中都能形成凝胶,可以发现随着末端烷基链增加有利于提高凝胶能力和凝胶的热力学稳定性。在紫外光照射下,在溶液中,Dn中的偶氮苯发生光致异构化,反式偶氮苯向顺式发生转化,虽然D10的环己烷溶液光致异构化性能最为显著(反式到顺式的转化比率达到66%),但是凝胶态下偶氮苯的光致顺反异构不能诱导凝胶-溶胶的转变。2、研究了含有不同长度柔性间隔基的基于酰肼基团的偶氮苯衍生物En(n=5、6、10)的有机凝胶性能及其多重响应性。E6和E10可以在N-N二甲基甲酰胺中形成纤维网络聚集的稳定凝胶,且E10的临界凝胶浓度高于E6,然而E5却不能形成凝胶。这可能是由于含有奇数间隔基的E5的弯曲构型导致E5的偶极矩增加,提高了E5在N-N二甲基甲酰胺(极性溶剂)中的溶解度,从而干扰E5分子的聚集。E6和E10的有机凝胶对多种环境刺激(包括温度,光,阴离子和p H)显示出刺激响应行为。在用UV照射有机凝胶时,由于偶氮苯基团发生光致异构化,从而导致凝胶向沉淀物转变,相应的形貌从纤维转变为球状聚集体。在En凝胶中直接加入阴离子(F~-和Ac O-)时,凝胶迅速坍塌为溶液并伴有颜色变化,通过阴离子滴定的紫外-可见吸收光谱和核磁氢谱证实是酰肼基团发生了去质子化过程导致的响应变化。另外,该有机凝胶还具有PH值响应性,加入碱和酸能诱导凝胶-溶胶的可逆转变,同时伴随颜色变化。这些研究的结果可以进一步理解小分子凝胶因子结构与性质的关系。3、研究了En和4-poxd-B8双组份有机凝胶的阴离子响应性质。不含有氢键的VA唑衍生物4-poxd-B8可以在二甲基亚砜中形成稳定凝胶,而E5不能形成有机凝胶,但具有阴离子响应性。E5和4-poxd-B8的混合物能够在二甲基亚砜中形成稳定的凝胶,并且该凝胶对F~-和Ac O-离子的刺激呈现不同的颜色变化,但凝胶状态不发生改变,达到了检测阴离子的目的且不会带来凝胶的坍塌。
[Abstract]:Small molecular organic gel is a kind of small molecular gel factor dissolved in solvent, intermolecular hydrogen bond interaction, 蟺-蟺 interaction, van der Waals force and other non-covalent bond interaction to form fiber network structure. The molecular structure of the gel factor has a great influence on the gel properties and irritability of organic gels. Therefore, the modification of the gel factors can greatly improve the functionality of the materials. For example, introducing functional groups that are responsive to external stimuli, such as light, electricity, sound, ions, acids and bases, temperature, etc., so as to achieve the external stimuli response of organic gels. Two derivatives of azobenzene (azobenzene are photoresponsive) derivatives based on hydrazide group (acyl hydrazide group containing abundant hydrogen bonds) were selected and their organic gels and their multiple reactivity were studied. To study the content as follows, we have studied the properties of organic gels and photo-responsibility.D7 can only form organic gels D8 in cyclohexane, and can form gels D10 in 1h2- dichloroethane and cyclohexane in 1h2- dichloroethane. Both cyclohexane and dimethyl sulfoxide can form gels. It can be found that with the increase of the terminal alkyl chain, the gel ability and the thermodynamics stability of the gel are improved. Under ultraviolet light irradiation, the azobenzene in the solution is photoisomerized. Trans azobenzene is converted to cis, Although the photoisomerization of D10 solution of cyclohexane was the most remarkable (the conversion ratio of trans-cis to cis was 66%), the photoisomerization of azobenzene in gel state could not induce the conversion of gel to sol. The properties of organic gels and their multiplicity. E6 and E10 can form stable gel aggregates of fiber network in N-N dimethylformamide, which is an azobenzene derivative based on acyl hydrazide group. The critical gel concentration of E10 was higher than that of E6, but E5 could not form the gel. This may be due to the increase of dipole moment of E5 due to the bending configuration of E5 with odd spacers, which increases the solubility of E5 in N-N dimethylformamide (polar solvent). Thus, organic gels that interfere with the aggregation of E5 molecules. E6 and E10 exhibit stimulative responses to a variety of environmental stimuli (including temperature, light, anions and pH). Photoisomerization of azophenyl groups occurs in organic gels irradiated by UV. As a result, the gel changed to precipitate, and the corresponding morphology changed from fiber to spherical aggregate. When anion FF- and Ac O-were added directly into en gel, the gel collapsed into solution and the color changed rapidly. The UV-Vis absorption and nuclear magnetic hydrogen spectra of anionic titration show that the acylhydrazide group deprotonates and the organic gel is also PH responsive. Adding alkali and acid can induce the reversible transition of gel and sol. The results of these studies can further understand the relationship between the structure and properties of small molecular gel factors, and study the anion response properties of en and 4-poxd-B8 bicomponent organic gels. Biological 4-poxd-B8 can form a stable gel in dimethyl sulfoxide. E5 could not form an organic gel, but the mixture with anionic responsiveness. E5 and 4-poxd-B8 could form a stable gel in dimethyl sulfoxide, and the gel showed different color changes in the stimulation of F- and Ac O- ions. However, the gel state does not change, the detection of anions and does not lead to the collapse of the gel.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O648.17

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