基于蒽和均三嗪的合成二维聚合物单体单晶可控生长及其大尺寸单分子膜制备

The discovery of graphene, a naturally occurring two-dimensional polymer, has initiated the continued explorations into different kinds of two-dimensional materials. However until recently, there was a breakthrough in the synthetic two-dimensional polymer single-crystals with precise crystallographic structures and the preparation of its monolayers. In light of its enormous potential applications in the fields of membrane separation and photoelectric materials, it is necessary to conduct in-depth studies on the important part of the preparation process of the monolayers, i.e. the crystallization process of the monomer. This project aimed at one of these monomers, which is a double-decker rotor-like monomer with three blades based on anthracene and s-triazine and easy to industrialize. On account of the research on crystallization thermodynamics and kinetics, the polymorph and morphology of the monomer single-crystals will be controlled. Also the interactions between the mixed solvent systems and the monomer single-crystals, two-dimensional polymer single-crystals and monolayers will be revealed to realize the controllable growth of the monomer single-crystals. And thus all the steps of the single-crystal method (synthesis and crystallization of the monomer, photopolymerization of the monomer single-crystals, and exfoliation into monolayers) for preparation of two-dimensional polymers will be integrated and optimized. A method to prepare free-standing large-size monolayers with uniformity of thickness will be constructed to accelerate its industrialization process, therefore advance the development of its applications in the above mentioned fields.

天然二维聚合物石墨烯的发现引发了过去十年人们对各种二维材料的持续探索，但人工合成的具有精确晶格结构的二维聚合物单晶及其单分子膜的制备直到最近才有了突破性进展。鉴于其在膜分离和光电材料领域巨大的应用潜力，有必要对其制备过程中单体结晶这一重要环节进行深入研究。本课题针对其中一种易于工业化的基于蒽和均三嗪的三叶双层转子式单体，拟在其结晶热力学和动力学研究基础上，控制单体单晶的晶型和晶习，揭示混合溶剂体系与单体单晶、二维聚合物单晶及其单分子膜之间的相互作用关系，从而实现单体单晶的可控生长。进而将单晶法制备二维聚合物中的各个步骤（单体的合成与结晶、光聚合反应和单分子层剥离）进行整合优化，建立一套制备厚度均匀的大尺寸自支持单分子膜方法，以加速其工业化进程，并推进其在上述领域中的应用开发。

天然二维聚合物石墨烯的发现引发了过去十几年人们对各种二维聚合物材料的持续探索，但人工合成的具有精确晶格结构的二维聚合物单晶及其单分子膜的制备直到最近才有了突破性进展。二维聚合物单体的结晶过程对其单分子膜的制备过程中光聚合反应及剥离有重要影响，而溶解平衡是结晶动力学及过程设计的基础，因此，本项目对一种基于反式肉桂酸的二维聚合物单体的相平衡热力学及其结晶规律进行了深入研究。主要研究内容与结果如下：.（1）选用异麦芽酮糖、岩藻糖、脯氨酸等小分子物质对本实验的溶解平衡测定方法进行验证，并对其溶解度数据进行了模型拟合分析，将模型计算值与文献报道值进行了对比，从而验证了本实验方法的可靠性和准确性。.（2）采用一步合成法制备出了二维聚合物单体，并对多种溶剂进行实验分析与筛选，最终确定二氯甲烷作为正溶剂，正己烷作为反溶剂；采用静态法测定了二维聚合物单体在二氯甲烷和正己烷二元溶剂体系中不同温度下的溶解度，实验结果表明：单体的溶解度随温度的升高而增大，但整体变化幅度并不大；单体的溶解度随二氯甲烷的摩尔分数的升高而增大，尤其当二氯甲烷摩尔分数大于0.60时，其溶解度增长幅度较大。.（3）根据溶解度数据变化规律，选择溶析结晶法对二维聚合物单体进行精制，并对结晶诱导期进行了研究；为了进一步研究二维聚合物单体的溶解度变化规律，采用Apelblat模型、CNIBS/R-K模型和Apel-JA模型对数据进行拟合关联，拟合效果较好；通过筛选确定紫外光是诱导二维聚合物单体发生光聚合反应最适合的光源；并对光聚合反应产物进行了剥离，采用原子力显微镜对制备的二维聚合物膜进行了表征。.本项目的研究结果为基于反式肉桂酸的二维聚合物单体的结晶工艺及后续光聚合、剥离过程开发提供了基础数据与设计依据，对于该新型二维材料在膜分离和光电材料领域的应用起到了积极的推动作用。