Responsive and cellulose-fibre based adsorbents for water clarification and disinfection

由于各种工业、市政和农业来源的污染，获得清洁水变得越来越具有挑战性，这增加了开发新的和替代的水净化技术的紧迫性和必要性。在水处理的各种技术中，使用吸附剂是最有效和最简单的方法之一。然而，开发多功能（例如，抗微生物）和响应性吸附剂仍然不足。拟议的研究旨在开发基于改性纤维素微纤维或长丝、纳米胶囊和多孔聚合物微粒的三种类型的新型吸附剂，这些吸附剂都与用于创新水过滤系统的绿色材料纤维素纤维相关。由博士生执行的具体分项目如下： 1)基于纤维素纤维的功能性吸收剂：官能团（例如，通过适当的反应，抗菌聚合物链将被接枝到纤维素微纤维（CMF）和纤维素长丝上;并产生一种新型的长纤维纸基过滤器，能够澄清水中的污染物并灭活捕获的细菌。此外，纤维/无机多孔填料杂化吸附剂将使用溶解的纤维素纤维与成孔剂来制备，以促进吸附剂回收。 2)响应性或智能纳米胶囊：为了提高基于纤维素纤维的吸收剂的性能，将合成一系列具有阴离子上边缘和阳离子下边缘的两性pH敏感性杯芳烃。这样的智能纳米胶囊可以很好地保留与纤维素纤维或单独用于可控的吸附/解吸触发的pH值变化。 3)功能性聚合物微胶囊或吸收剂：为了吸收具有相对大尺寸的污染物，将使用多孔碳酸钙作为模板通过原位自由基共聚制备具有定制孔径和功能的pH响应性和抗微生物聚合物微胶囊，以在适当的pH下去除，产生模板的镜像孔结构。 所有提出的功能性吸附剂将被全面表征，为吸附行为的基本理解，这是HQP培训的重要意义。由此产生的吸附剂将导致纤维素纤维的增值产品，并解决日益关注的工业水污染和与饮用水相关的水传播疾病。

Access to clean water is becoming more challenging due to the pollution from a wide variety of industrial, municipal and agricultural sources, which raises the urgency and need to develop new and alternative technologies for water clarification. Among various technologies for water treatment, using adsorbents is one of the most effective and simplest approaches. However, the work on developing multi-functional (e.g., antimicrobial) and responsive adsorbents is still inadequate. The proposed research aims at developing three types of novel adsorbents based on modified cellulose microfibrils or filaments, nanocapsules and porous polymeric microparticles, which are all associated with green materials - cellulose fibres for innovative water filter systems. The specific sub-projects, to be performed by PhD students, are as follows: 1) Cellulose-fibre based functional absorbent: the functional groups (e.g., carboxyl groups for complexing with heavy metal ions in water) and antimicrobial polymer chains will be grafted on cellulose microfibrils (CMF) and cellulose filaments via proper reactions; and create a novel paper-based filter with long fibres which enable to clarify contaminants in water and deactivate the bacteria entrapped. Moreover, the fibre/inorganic porous filler hybrid adsorbents will be prepared using dissolved cellulose fibres with pore forming agents to facilitate the adsorbent recovery. 2) Responsive or smart nanocapsules: to enhance the performance of cellulose fiber-based absorbents, a range of amphoteric pH-sensitive calixarenes with anionic upper rim and cationic lower rim will be synthesized. Such smart nanocapsules can be well retained with cellulose fibres or used alone for the controllable adsorption/desorption triggered by pH change. 3) Functional polymeric microcapsules or absorbents: to absorb the contaminants with relatively large size, pH-responsive and antimicrobial polymeric microcapsules with tailored pore size and functionality will be prepared via an in-situ free-radical copolymerization using porous calcium carbonate as a template to be removed under appropriate pH, creating the mirrored pore structure of the template. All functional absorbents proposed will be comprehensively characterized for the fundamental understanding of adsorption behaviors, which is of great significance for HQP training. The resulting adsorbents will lead to the value-added products from cellulose fibres and tackle the increasing concern about industrial water contamination and water borne diseases associated with drinking water.