二元聚合物刷修饰毛细管柱的研制及其电色谱分离机理研究

In order to solve the problems of a single polymer modified capillary columns, such as low lifetime, poor reproducibility, irreversible non-specific absorption etc, the project will design binary polymer brushes(e.g. one is to prevent non-specific interaction, the other is to create specific interaction for analysis.) as novel analytical media in capillary columns and research their analytical mechanisms. Two types of catecholic initiators are chemically bound onto the inner wall of the capillary and initiate polymerizations successively, surface-initiated ring-opening metathesis polymerization and then surface-initiated atom transfer radical polymerization respectively, to form binary polymer brushes in high grafting density and tunable brush thickness. The electroosmotic flow in the separation of proteins, amino acids and etc will be affected by controlling different polymer brushes types and grafting thickness. The lifetime of capillary column will be enhanced by controlling the grafting amount to screen the -Si-O-R and by reducing the non specific interaction. The preparation approach of capillary columns with comprehensive high analytical performance will be optimized by systematic study on grafting polymerization, physiochemical behavior, and electrophoresis. By the implementation of the project, novel approach for binary polymer brushes modified capillary columns and for the electrochromatographic separation will be developed to overcome drawbacks of a single polymer modified column, and to enhance the separation efficiency and reproducibility.

针对单一聚合物键合毛细管电泳柱键合量较低、功能单一、对蛋白质不可逆吸附等缺点，在多巴胺化学基础上，本项目拟设计制备抗蛋白吸附的二元聚合物刷键合毛细管柱（一种聚合物抑制蛋白的非特异性吸附，另一种改变蛋白与色谱柱的相互作用），研究其分离机制，具有较大的创新性。将多巴胺引发剂自组装键合到毛细管内壁，通过表面引发开环易位聚合和原子转移自由基聚合接枝高密度的功能性二元聚合物刷；通过有效控制毛细管内表面聚合物刷的种类和涂层厚度，达到控制电渗流的目的；改变聚合物接枝量和其在毛细管内表面上的结构，更好地掩蔽键合在毛细管内壁上的-Si-O-R键和减小非特异性吸附，提高毛细管柱的寿命；对毛细管柱的聚合层结构、物理性质和电色谱分离行为进行表征，优化制柱参数，确定制柱方法。通过本项目的实施，可以改善单一聚合物修饰毛细管柱的功能缺陷，提高对蛋白质等的分离效率和重现性，拓展二元聚合物刷修饰毛细管柱的制备方法和应用范围

为了改善单一聚合物键合色谱分离材料键合量低、分离功能单一、对蛋白质不可逆吸附等缺点，本项目一方面采用分步聚合和交联聚合的方式，将两种聚合物共同修饰到硅胶表面，制备了二元聚合物修饰硅胶的色谱分离材料，材料表现出了多相互作用模式，在色谱分离性能和色谱柱效上均优于单一聚合物键合的色谱分离材料，充分体现了二元聚合物修饰色谱分离材料的性能优势；另一方面，为了进一步控制和提高聚合物的修饰量，本项目采用表面原位聚合和层层物理涂覆的方式将亲水性聚合物包裹到硅胶表面，制备了多种亲水聚合物包裹硅胶的核-壳型色谱分离材料，通过控制和提高硅胶表面聚合物的含量，改善了对多种亲水化合物的分离性能，同时也为制备其它种类聚合物包裹硅胶色谱分离材料提供了简单有效的方法。通过上述研究工作，改善了单一聚合物键合色谱分离材料的功能缺陷，提高了材料的分离效率和重现性，拓展了聚合物修饰色谱分离材料的制备方法和应用范围。