纳米结构的聚吡咯纤维和薄膜的可控制备研究

发布时间：2019-03-18 15:12

【摘要】：近年来,聚吡咯因在传感器、电磁屏蔽材料、电极材料、催化剂、药物载体以及防腐蚀等领域具有极其广阔的应用前景而引起了人们的广泛关注。其中聚吡咯材料的微观结构形貌与其物性的紧密关系更是人们研究的重点,但如何实现聚吡咯材料形貌的可控制备却一直是人们面临的挑战性的难题。本文采用双软模板法制备聚吡咯纳米材料,该部分研究分为两个体系,以十二烷基苯磺酸钠(SDBS)和十二烷基硫酸钠(SDS)为双模板来制备聚吡咯纳米颗粒(球);以十二烷基苯磺酸钠(SDBS)和十六烷基三甲基溴化铵(CTAB)为双模板来制备聚吡咯纳米纤维。在实验中,考察了单模板法与双模板法制备得到的聚吡咯形貌的区别,探索了掺杂酸的浓度及种类、聚合时间、聚合温度对聚吡咯形貌的影响。研究表明,在SDBS和SDS聚合体系中,随着盐酸浓度的增大,制备得到的聚吡咯纳米颗粒尺寸逐渐增大,当以柠檬酸为掺杂酸时,聚吡咯呈均一规整的类球状。CTAB与SDBS聚合体系,聚合时间越长,聚吡咯纳米纤维表面越致密;利用水热法制备聚吡咯,在相同条件下得到的是纳米颗粒而不是纳米纤维。在气液界面处采用界面聚合法制备聚吡咯超薄膜的实验中,考察了表面活性、氧化剂种类及浓度、单体浓度、掺杂酸、聚合时间、聚合温度等因素对界面处形成的聚吡咯薄膜形貌的影响。表面活性剂SDBS的加入改变气液界面处的活性,降低了界面处的表面自由能,从而使得聚吡咯超薄膜更容易形成;随着聚合时间的增加,聚吡咯薄膜中与液相接触一侧的表面粗糙度逐渐增大,而与气相接触一侧的表面则保持均一光滑的形貌并无明显的变化;在以盐酸为掺杂酸的聚合体系中得到厚度达20 nm的聚吡咯超薄膜,由于盐酸的掺杂作用,聚吡咯薄膜导电性得到极大的提高。将吡咯单体水溶液进行一定程度预氧化后再进行气液界面聚合,成功制备出聚吡咯超薄多孔膜。研究表明,单体的预氧化程度以及单体的浓度是决定聚吡咯多孔膜是否出现的关键因素。在添加SDBS的聚合体系中,随着SDBS浓度的增加,聚吡咯多孔膜的孔洞尺寸逐渐减小且数量逐渐减少,当SDBS浓度达到1 mM时,多孔膜演变为无孔洞的致密膜。
[Abstract]:In recent years, polypyrrole has attracted wide attention because of its wide application prospects in sensors, electromagnetic shielding materials, electrode materials, catalysts, drug carriers and corrosion protection. Among them, the relationship between microstructure and physical properties of polypyrrole materials is more important, but how to realize the controllable preparation of polypyrrole materials morphology has always been a challenging problem. In this paper, polypyrrole nanoparticles were prepared by double soft template method. This part is divided into two systems: sodium dodecyl benzene sulfonate (SDBS) and sodium dodecyl sulfate (SDS) as double templates to prepare polypyrrole nanoparticles (spheres). Polypyrrole nanofibers were prepared by using sodium dodecylbenzenesulfonate (SDBS) and cetyltrimethylammonium bromide (CTAB) as double templates. In the experiment, the differences of the morphology of polypyrrole prepared by single template method and double template method were investigated, and the effects of the concentration and type of dopant acid, polymerization time and polymerization temperature on the morphology of polypyrrole were investigated. The results show that the size of polypyrrole nanoparticles increases with the increase of hydrochloric acid concentration in the polymerization system of SDBS and SDS. When citric acid is used as dopant acid, polypyrrole exhibits uniform spherical shape. The longer the polymerization time, the denser the surface of polypyrrole nanofibers. Polypyrrole was prepared by hydrothermal method. Under the same conditions, nano-particles were obtained instead of nano-fibers. The surface activity, oxidant type and concentration, monomer concentration, dopant acid and polymerization time of polypyrrole ultrathin films prepared by interfacial polymerization at gas-liquid interface were investigated. The effect of polymerization temperature and other factors on the morphology of polypyrrole films formed at the interface. The addition of surfactant SDBS changes the activity at the gas-liquid interface and reduces the surface free energy at the interface, which makes the polypyrrole ultrathin film easier to form. With the increase of polymerization time, the surface roughness of polypyrrole film on one side of contact with liquid phase increases gradually, but the surface of contact side of polypyrrole film with gas phase has no obvious change of uniform and smooth morphology. Polypyrrole ultrathin films with thickness of 20 nm were prepared in the polymerization system with hydrochloric acid as dopant acid. Due to the doping of hydrochloric acid, the conductivity of polypyrrole films was greatly improved. Polypyrrole ultrathin porous membrane was successfully prepared by pre-oxidation of pyrrole monomer solution and gas-liquid interface polymerization. The results show that the degree of preoxidation and the concentration of monomer are the key factors to determine the appearance of polypyrrole porous membrane. In the polymerization system with the addition of SDBS, with the increase of SDBS concentration, the pore size of polypyrrole porous membrane decreased gradually and the number decreased gradually. When the concentration of SDBS reached 1 mM, the porous membrane evolved into a dense porous membrane.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O633.5;TB383

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