Controllable Preparation And Application Of Hierarchical Porous Materials

Hierarchies are present everywhere in our environment such as in biological systems,from simple unicellular organisms to the more complex human body.There are some interesting examples in nature,such as hollow bamboo,honeycomb with hexagonal cells,and alveoli in the lungs.Design and construction of porous architectures that mimic structures found in nature in synthesized materials,down to the micro-and nanoscale range,have long been an important science subject.Porous polymers especially have received an increased level of research interest because of their potential to merge the properties of both porous materials and polymers.Hierarchically porous silica materials with well-defined morphologies have been of growing interest,because of their potential applications in catalysis,adsorption,separation,and biomedical systems.Many successful dual exotemplating methods have been developed to prepare hierarchically porous materials.In this paper,we prepared hierarchically porous silica,amphiphilic hierarchically porous poly(dimethyl siloxane)and three-dimensional ordered macroporous hydrogel.1)Using three-dimensional ordered macroporous crosslinked polystyrene(3DOM CLPS)as a template offers an efficient way to construct an ordered and interconnected meso-macroporous structure.In this research,the functionalized 3DOM CLPS conducted TEOS sol-gel chemistry to prepared hierarchically porous silica.2)In order to further improve the mass-transfer and the activity for biocatalyst in the hydrocarbons,in this project,3DOM poly(dimethylsiloxane)(PDMS)with APCN pore-wall will be prepared by a water-soluble colloid crystal template and the method of polymer chemistry and physics to act as enzyme support for preparation of biodiesel in hydrocarbons.the preparation and control of the structures of the amphiphilic hierarchically porous PDMS will be investigated to construct a novel porous polymer with high performance,and the relationships between the microstructure(hierarchically porous structures and the HI/HO phases)and the synthesis conditions or confined spaces also will be illustrated.3)The 3DOM poly-N-isopropylacry lamide hydrogel was used to prepare the immobilized lipase.The three-dimensional ordere macroporous structure can increase the contact area between the enzyme and substrate,and reduce the mass transfer resistance,which is suitable for the immobilization of the enzyme.In the experimental process,first of all,the rates of the swelling and deswelling and reswelling were studied,then,the optimum concentration and optimum load time were studied.Data shows that,the optimal enzyme concentration was 20 mg/m L;the optimal loadtime was 4h.After that,the optimal p H of the immobilized enzyme was studied.The conclusion was that the optimum p H value was 7.In addition,the study on the repeated availability of materials was carried out.The experimental data showed that: after 7 times,it can still maintain the activity of 60%.