Functional cellulosic porous materials: structure design, surface engineering, and applications

The application of functional porous materials for tackling challenges in the areas of environment, energy, and healthcare has attracted distinguished interest. Cellulose within this class of materials, which is one of the most abundant and renewable polymers, provides attractive alternatives to synthetic plastics for numerous applications. The inherent properties of hydrophilicity, biodegradability and the rich chemistry enabled by its hydroxyl groups make cellulose easy to modify and functionalize. When cellulosic materials are endowed with controlled (micro)porous structures, a range of applications becomes feasible due to the combined advantages of controlled porosity, high specific surface area, and the intrinsic materials’ properties of cellulose. For example, porous cellulosic materials with precise surface modification and engineered pore structure have been employed in molecular delivery, catalyst support, absorption, separation, and thermal insulation. In this Thesis, we presented different structure designs and surface modification methods of cellulosic porous materials which have great potential for application in the areas of environment, energy, and healthcare. Firstly, we designed cellulosic porous materials with a Janus structure. This unique structure with different wettability provides these materials with novel application opportunities. We explored the application of this Janus structure in hemostatic wound dressing and in evaporators for seawater desalination, and obtained superior results compared with some commercial products and results shown in other published work. Second, based on our previous work and the widely researched polymer PFS, we used a post-modification and physical mixing method to prepare two kinds of porous materials. One is a wearable heater and the other is a catalyst support. In order to further explore the combination of cellulose and PFS, we added some PFS structures in the outlook chapter, hoping to broaden the functionalization options of cellulosic porous materials. Overall, the results presented in this thesis were realized by introducing novel structure and surface modification methods for porous materials with the aim of gaining access to new application areas, and to hopefully give inspiration to researchers in the development of advanced cellulosic porous materials.