烷基取代咪唑类离子液体聚合物在溶液中的聚集过程及应用

发布时间：2018-05-08 08:37

本文选题：离子液体聚合物 + 聚集行为　；参考：《浙江理工大学》2017年硕士论文

【摘要】：离子液体聚合物(PILs)保留了离子液体的结构特性,具有自发聚集能力,但与小分子的离子液体(ILs)相比,PILs在溶液中的运动过程受到的影响更多,组装过程也更为复杂。PILs有序体的构建多数采用先单体有序组装,然后聚合锁定的方法进行,但聚合过程中单体有序结构被破坏是其进一步应用的瓶颈。此外,PILs有序体的结构设计和其功能性材料性能的优化是近些年的研究热点,但对于PILs分子链如何自发地进行有序聚集,尤其是其聚集过程的热力学行为很少见报道。基于此,本文首先采用自由基聚合的方法制备PILs,然后将PILs溶于溶剂,系统探究PILs在溶液中的自发聚集过程及相关的影响因素。另外,利用该方法所制备的PILs在PH响应、抑菌材料方面的应用还需要进行进一步评价。本文合成咪唑类离子液体聚合物poly[C_nVIm~+][X~-](n=8,12,16)(X为配对离子),利用烷基链和阴离子的结构可设计性,探究其在有机溶剂中的聚集行为、刺激响应性和抗菌功能上应用。论文主要结论如下:(1)利用自由基聚合合成不同烷基链长的咪唑类离子液体聚合物,poly[CnVI m+][Br~-](n=8,12,16),其在正丙醇中可以自发聚集成有序结构,当烷基链为16时,其在正丙醇中的聚集形态为多层“洋葱状”结构,这种“洋葱状”形貌与阴离子种类无关,而且可以长时间保持。(2)通过电导率法对poly[C_nVIm~+][Br~-](n=8,12,16)在正丙醇的热力学行为的进行研究。结果表明,PILs在正丙醇中的聚集过程是熵驱动的自发过程。随着烷基链的增加,临界聚集浓度(CAC)降低,每条烷基链对吉布斯自由能(?G_m~θalkyl)的贡献增加,聚集过程是在疏水作用下完成聚集过程。当向体系中加入不良溶剂时,CAC和吉布斯自由能(?G_m~θ)随着不良溶剂体积分数的增加而降低,自发聚集行为更容易进行。(3)通过阴离子交换实验将poly[C_nVIm~+][Br~-](n=8,12,16)引入具有pH响应的阴离子(Mo~-),功能化后的PILs表现出优异的pH响应性。随着pH的增加,PILs溶液颜色由红色变成黄色,其聚集尺寸随着pH的增加而明显增大。具有高阴离子交换率的poly[C_nVIm~+][Br~-]x[Mo~-]y对酸碱响应更为“灵敏”,同时,烷基链的增加使得PILs对酸碱响应性变得“迟钝”。(4)将聚合后的poly[C_nVIm~+][Br~-](n=8,12,16),通过透析的方式得到PILs胶束,研究PILs胶束对金黄色葡萄糖球菌(S.aureus)和大肠杆菌(E.coli)抗菌性能。不同烷基链长的PILs的临界抑菌浓度(MIC)从低到高依次为:poly[C_(12)VIm~+][Br~-]poly[C_(16)VIm~+][Br~-]poly[C_8VIm~+][Br~-],并且poly[C_(12)VIm~+][Br~-]与细菌接触1h后,细菌生存率几乎为0。通过电荷屏蔽实验研究了烷基链对抑菌的贡献,对于Poly[C_(12)VIm~+][Br~-]而言,烷基链对S.aureus抑菌的贡献达到60%,对E.coli抑菌的贡献达到67%。本文系统的研究了poly[C_nVIm~+][Br~-](n=8,12,16)在纯溶剂和不良溶剂存在条件下的自发聚集过程和热力学行为,考察了其在有机溶剂中的pH刺激响应特性以及对金黄色葡萄糖球菌(S.aureus)和大肠杆菌(E.coli)抗菌性能。研究结果对于PILs功能材料的结构设计和性能调控提供新思路。
[Abstract]:Ionic liquid polymers (PILs) retain the structural characteristics of ionic liquids and have the ability to assemble spontaneously, but compared with the ionic liquids (ILs) of small molecules, the movement process of PILs in the solution is more affected. The assembly process is also more complex for the construction of the complex.PILs ordered body by the ordered assembly of monomers, and then the method of polymerization locking. In addition, the structural design of the PILs ordered body and the optimization of its functional material performance are the hot spots in recent years. However, it is rare to report on how the PILs molecular chain is organized spontaneously and orderly, especially the thermodynamic behavior of its aggregation process. In this paper, we first prepare PILs by free radical polymerization, and then dissolve PILs in the solvent and systematically explore the spontaneous aggregation process of PILs in the solution and the related factors. In addition, the application of the PILs prepared by this method in PH response and the application of bacteriostasis materials need to be further evaluated. This paper syntheses imidazole ionic liquids. Polymer poly[C_nVIm~+][X~-] (n=8,12,16) (X is paired ion), using the structure of alkyl chains and anions to design, explore its aggregation behavior in organic solvents, stimulate responsiveness and antibacterial function. The main conclusions are as follows: (1) synthesis of imidazole ionic liquid polymers with different alkyl chain length by free radical polymerization, Po Ly[CnVI m+][Br~-] (n=8,12,16), in n-propanol, can be spontaneously integrated into an ordered structure. When the alkyl chain is 16, the aggregation morphology in n-propanol is a multilayer "onion like" structure, which is independent of the type of anions and can be maintained for a long time. (2) poly[C_nVIm~+][Br~-] (n=8,12,1) by conductivity method. 6) the thermodynamic behavior of n-propanol is studied. The results show that the aggregation process of PILs in n-propanol is a spontaneous process of entropy driven. With the increase of alkyl chain, the critical concentration (CAC) decreases, and the contribution of each alkyl chain to Gibbs free energy (? G_m~ theta alkyl) is increased, and the aggregation process is completed under the hydrophobic action. When the solvent is added to the system, the CAC and Gibbs free energy (? G_m~ theta) decreases with the increase of the volume fraction of the bad solvent, and the spontaneous aggregation behavior is easier. (3) the anion exchange experiment is used to introduce the poly[C_nVIm~+][Br~-] (n=8,12,16) into the pH response anion (Mo~-). The functional PILs shows excellent pH response. With the increase of pH, the color of PILs solution is yellow from red to yellow, and its aggregation size increases obviously with the increase of pH. The poly[C_nVIm~+][Br~-]x[Mo~-]y with high anion exchange rate is more "sensitive" to the acid base response. At the same time, the increase of alkyl chain makes PILs to be "dull" to the acid base response. (4) poly[C_nV after polymerization Im~+][Br~-] (n=8,12,16), PILs micelles were obtained by dialysis to study the antibacterial properties of PILs micelles to Staphylococcus aureus (S.aureus) and Escherichia coli (E.coli). The critical inhibitory concentration (MIC) of PILs with different alkyl chain length (MIC) from low to high was poly[C_ (12) VIm~+][Br~-]poly[C_ (16) VIm~+][Br~-]poly[C_8VIm~+][Br~-], and pol. After y[C_ (12) VIm~+][Br~-] was exposed to 1H with bacteria, the survival rate of bacteria was almost 0.. The contribution of alkyl chain to bacteriostasis was studied by the charge shielding experiment. For Poly[C_ (12) VIm~+][Br~-], the contribution of alkyl chain to S.aureus was 60%. The contribution of E.coli bacteriostasis to 67%. system was studied in poly[C_nVIm~+][Br~-] (n=8,12,16). The spontaneous aggregation process and thermodynamic behavior under the presence of pure solvent and bad solvent were used to investigate the response characteristics of pH stimulation in organic solvents and the antibacterial properties of Staphylococcus aureus (S.aureus) and Escherichia coli (E.coli) in organic solvents. The results provided new ideas for the structure design and performance regulation of PILs functional materials.

【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O631

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