两亲性共轭高分子聚(对亚苯基丁二炔)的合成与二维自组装  

Synthesis and Two-dimentional Self-assembly of Amphiphilic and Conjugated Polymers Based on Poly(phenylenebutadiynylene)s

作　　者：江晨 武星 张娜 陈放 白如科[1] Chen Jiang;Xing Wu;Na Zhang;Fang Chen;Ru-ke Bai(Key Laboratory of Soft Matter Chemistry,Chinese Academy of Science;Department of Polymer Science and Engineering,University of Science and Technology of China,Hefei 230026)

机构地区：[1]中国科学院软物质化学重点实验室中国科学技术大学化学与材料科学学院,合肥230026

出　　处：《高分子学报》2018年第11期1442-1450,共9页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号21674101)资助项目

摘　　要：设计、合成了两亲性线型共轭聚合物聚(对亚苯基丁二炔)(A-PPB),研究了它在溶液中的二维自组装行为.首先合成了A-PPB的前驱体聚合物PPB,利用核磁氢谱(1H-NMR)、傅里叶红外光谱(FTIR)和拉曼光谱对聚合物的结构及分子量进行了表征.然后通过水解反应,获得了两亲性共轭聚合物A-PPB,并考察了它在水、甲醇以及甲醇/甲苯混合溶剂中的自组装行为.透射电子显微镜(TEM)的测试结果表明,A-PPB在水溶液中自组装形成了二维超分子纳米片(2D-SNS),尺寸达几微米;用原子力显微镜(AFM)测得2D-SNS的厚度为5 nm左右,由不超过3层的二维超分子聚合物层堆积而成.高分辨透射电子显微镜(HRTEM)、选区电子衍射(SAED)及X-射线衍射(XRD)的测试结果表明,2D-SNS是由A-PPB分子链平行堆积而成.在甲醇溶剂中,A-PPB形成了无规聚集体,而在甲醇/甲苯混合溶剂中则自组装形成了多层堆积的二维超分子纳米片.对比研究表明,非亲水的PPB在氯仿/甲醇混合溶剂中形成的是较厚的层状聚集体.还发现聚合物的链长对于自组装形成二维超分子片层也会有影响,当用数均聚合度为8的两亲性低聚(对亚苯基丁二炔)(A-OPB)在水溶液中进行自组装时,只能形成尺寸较小的无规聚集体.由此可见,聚合物的两亲性、电荷排斥作用以及聚合物链长等因素都会对共轭聚合物的二维自组装行为产生重要影响.Amphiphilic and conjugated polymers based on poly（phenylenebutadiynylene）s （A-PPB） were designed and synthesized, which were consisted of a hydrophobic rigid conjugated main chain and hydrophilic flexible side chains with carboxylic anions. Structure and degree of polymerization （DP） of the polymers were examined by proton nuclear magnetic resonance （1H-NMR）, Fourier transform infrared spectroscopy （FTIR） and Raman spectroscopy. The two dimensional self-assembly of the amphiphilic conjugated polymers was investigated in different solvents and their mixtures. The morphology of the aggregates was characterized by transmission electron microscopy （TEM）. The results showed that A-PPB in water self-assembled into twodimentional supramolecular nanosheets （2D-SNS） with size ranged from hundred nanometers to several microns. The thickness of 2D-SNS was measured to be about 5 nm by atomic force microscopy （AFM）, indicating a stack of 3 layers. The results of high-resolution TEM （HRTEM）, selected-area electron diffraction （SAED） and X-ray diffraction （XRD） demonstrated that 2D-SNS was formed by the parallel arrangement of A-PPB, and the distance between the adjacent two A-PPB chains was consistent with the typical π-π stacking distance. On the other hand, A-PPB in methanol formed irregular aggregates because of its high solubility. However, when toluene was added into the methanolsolution of A-PPB, multilayered aggregates were obtained. Moreover, self-assembly of the nonamphiphilic precursor PPB was also examined in a mixed solvent of chloroform and methanol, and the TEM images showed that PPB formed multi-layered aggregates. This result indicated that the amphiphilicity and the electrostatic repulsion of the polymer chains played an important role in the formation of the layered sheets. In addition, DP of A-PPB is also important for 2D self-assembly of the polymers. When DP was 8, amphiphilic oligo（phenylenebutadiynylene）s formed disordered aggregates. In conclusion, this

关 键 词：两亲性 共轭聚合物 二维自组装 超分子纳米片 

分 类 号：O632.17[理学—高分子化学]