有序介孔高分子功能材料微观结构的正电子湮没研究

Recently, ordered mesoporous functional polymers have received considerable attentions. It is very important to characterize the microstructure of such materials comprehensively and accurately. In this project, the microstructure of the ordered mesoporous polymers (especially phenolic resin) has been characterized with positron annihilation methods deeply and carefully. The information of the different pores containing in the ordered mesoporous functional polymers has been obtained. The positron annihilation mechanism in the pores has been discussed. Meanwhile, other methods has been used in the characterization, such as N2 absorption, HR-TEM, XRD,TGA. The changes in the microstructure caused by process optimization, preparation of functional polymer skeleton(SO3H), transition metal active components loaded, high temperature carbonization have been deeply investigated. The relationships between the changes of microsytucture and properties (such adsorption and catalytic properties) have been thoroughly discussed. The modification mechanism of such functional polymer materials has been explained in the view of microscopic. The implementation of the project is of positive significance for expanding the application of nuclear analytical techniques in the analysis of emerging materials.

有序介孔高分子材料是近期极受关注的热门纳米材料，全面、准确地表征其微观结构（特别是其孔结构）是对材料的制备工艺进一步优化与功能化的必要基础。在本项目中，拟综合运用各种正电子湮没技术，以稳定、规则介孔酚醛树脂为代表的介孔高分子材料的微观结构进行深入、细致的研究，获得所制备的功能化有序介孔高分子材料的微孔、介孔、孔容等结构信息，探讨入射正电子在材料不同结构的孔穴与缺陷中的湮没机制，同时结合N2吸附、HR-TEM、XRD、TGA等常规手段分析结果，深入剖析有序介孔高分子材料由于制备工艺优化、高分子骨架功能化（磺酸基功能化）、过渡金属活性组分负载、高温炭化等的实施对材料微观结构的影响，并与材料吸附性能、催化性能等关联起来，从微观角度解释改性机理，并为材料的进一步优化提供依据。本项目的实施，对于拓展核分析技术在新兴热门材料分析中的应用具有积极的意义。

本项目的主要研究工作是合成了系列介孔酚醛树脂、氮掺杂酚醛树脂和二氧化硅介孔材料，主要采用核分析技术正电子湮没寿命谱，结合多普勒增宽能谱、TEM、SEM、IR、XRD和氮气吸附等分析手段，从介孔特性的角度研究了聚合物制备条件与其微观结构的关系，探讨了材料的介孔规整性与金属离子分散均匀度、催化活性、催化反应的循环性和气体吸附量的内在联系。分析了稠环结构π电子对正电子湮没行为的影响，认为π电子对正电子的O-Ps湮没有淬灭作用。同时，制备了聚乙烯醇/蒙脱土和聚氨基葡糖/蒙脱土复合材料，研究了层间孔穴尺寸和数量对负载Pd和Cu催化剂活性、催化反应循环次数的影响。考察了电纺丝聚氨基葡糖/聚丙烯酸钠纳米复合纤维溶胀后的自由体积尺寸、氨基的含量对吸附Cr2O7-2能力的作用。