多级孔道结构聚合物中空粒子的设计、制备及染料吸附性能研究

Adsorption process is one of the most effective techniques for dye removal due to its flexibility, simplicity and high efficiency. However, the disadvantages of conventional adsorbents, including relatively high cost, low adsorption capacity, slow adsorption rate and the difficulty in regeneration, remain big challenge for their industrial application. Therefore, the development of high performance, low cost and recyclable adsorbents has attracted considerable research attention. The adsorption performance of the adsorbents is largely dependent on their chemical composition and porous structure. Taking these into consideration, a novel kind of functional hollow polymer particle with crosslinked shell and multi-level porous structure are specially designed. The high surface-to-volume ratio, multi-level porous structure and high density of functional groups, making them suitable adsorbents for dyestuffs adsorption. Based on our previous work, we will develop a simple, high yield and scalable method for the fabrication of multi-level porous hollow polymer particles (MPHPPs). The as-prepared MPHPPs will be further functionalized and serve as an efficient adsorbent for the removal of dyestuffs, and the adsorption process and the adsorption mechanism will be fully studied. The selectivity of these functional MPHPPs to different kind of dyes, the adsorption capacity and rate, and their regeneration/reuse will be investigated in detail. The present research not only has great significance for the structure design of efficient adsorbent, but also leads to a series of high performance adsorbents for the treatment of dye wastewater.

吸附法是染料废水处理的重要方法，具有适应性广、操作简便和处理效果好等优点，但常用吸附剂存在成本高、吸附速率慢、吸附容量低及再生困难等缺点，迫切需要开发低成本、高效率和易再生的吸附材料。本申请在对吸附材料结构与性能关系深入分析的基础上，设计了一种新型的多级孔道结构功能性聚合物微球，用于染料分子的高效吸附。围绕这种设计，拟在以往研究工作基础上，开发出一种工艺简单、产率高、易于工业化生产的多级孔道结构聚合物中空粒子制备方法；并将所制备的多级孔道结构聚合物中空粒子进一步功能化，用于染料废水的处理；从热力学和动力学角度研究其对染料分子的吸附过程及机理，探究吸附性能和结构之间的构-效关系；从吸附选择性、吸附容量和吸附速率以及解吸附-再生等方面探讨其在染料废水处理领域的应用前景。本研究不仅在新型染料吸附材料结构设计方面具有重要学术价值，而且在染料废水问题的解决方面具有现实意义。

吸附法是染料废水处理最有效的方法之一，但传统吸附材料存在成本高、吸附速率慢、吸附容量小以及再生困难等缺点。开发吸附量高、选择性好、易再生的新型吸附材料具有重要的理论价值和实用意义。本研究在分析吸附材料结构与性能关系的基础上，设计、制备了一种具有多级孔道结构的中空聚合物微球（HPP），其壳层中含有高密度酸酐基团，进一步通过化学改性的方式制备了羧基及胺基功能化中空聚合物微球（HPP-COOH和HPP-NH3+）；所制备的功能性HPP具有较大的比表面积和极高的功能性基团密度，可作为高效吸附剂用于废水中染料分子的选择性吸附脱除。主要结论如下：.1、基于自稳定沉淀聚合，采用分步加料一锅法制备了壳层为二乙烯基苯和MAH交联聚合物，核为MAH-St交替共聚物的核壳聚合物微球（PMS@PMSD），且PMS@PMSD核-壳层厚度可控、壳层交联程度可调，进一步采用溶剂刻蚀的方法得到酸酐功能化HPP。.2、通过酸酐基团水解及胺解反应，制备了HPP-COOH和HPP-NH3+，其壳层具有互通介孔结构，且功能性基团含量分别高达9.2 mmol/g和2.72 mmol/g，可作为高效吸附剂分别用于碱性和酸性染料分子的选择性吸附。.3、以甲基蓝（a-MB）和亚甲基蓝（b-MB）为模型染料分子研究了功能性HPP的吸附性能。HPP-COOH对碱性染料b-MB具有选择性吸附，吸附等温线符合Langmuir模型，pH=10时，吸附容量（qmax）高达1603 mg/g，且10min达到吸附平衡，远快于常规吸附剂；HPP-NH3+对酸性染料a-MB表现出了较高的qmax（406 mg/g）和较快的吸附速率，且随壳层交联程度下降，吸附速率加快且qmax显著增加至1296 mg/g；另外，qmax具有显著地的pH响应性，溶液pH由2升至9，qmax由406显著降低至59 mg/g。.3、所制备功能性HPP具有优异的解吸附-再生和重复使用性能，通过调整溶液pH可实现解吸附，回收染料的同时实现吸附剂的再生；经五次吸附-解吸附循环后，吸附剂的吸附性能无明显变化。.由于吸附容量大、吸附速度快、易再生/可重复使用，所制备的功能性HPP在染料废水处理方面有广阔的应用前景。