Silica Based Hierarchical Porous Material: Preparation,Characterization And Application

From the ancient times to today,mankind has been devoted to discovering and designing new types of materials.With the continuing advances and development of nanotechnology,new possibilities emerged to enable the manufacture of hierarchical materials with constituents modified on the nanoscale.In recent years,the technology of hierarchically porous materials has been continuously developed,but the development of hierarchically porous materials with high quality mass transfer capacity and load capacity is still a challenge.Silica-based materials are high mechanical properties,good biocompatibility,and versatility of surface functionalization.Herein,in this paper,we combined the three-dimensional macroporous?3DOM?ordered material with a periodic regular structure and a sol-gel technique with mild reaction conditions to designed and prepared a hierarchical porous monolith silica?HPM-Si O₂?material and a hierarchical porous microcapsule?HPMC-Si O₂?material.The amphiphilic porous conetwork polysiloxane material was prepared using the dense hexagonal colloidal crystals as templates.1.Hierarchical porous monolith silica?HPM-Si O₂?material was prepared by using threedimensional ordered macroporous crosslinked polystyrene?3DOM CLPS?as a template.Sulfonation of the template with different degrees of cross-linking yields 3DOM templates with different amounts of sulfonic acid groups,so that mesopores can be precisely controlled.In addition,the HPM-Si O₂ can be gold-modified to catalyze the reaction of pnitrophenol as a model reaction,which verifies the excellent performance of the material as a carrier for catalysis.2.After the sulfonation of the template with styrene having a high degree of cross-linking,the mixture of tetraethoxysilane and a mixed solvent of ethanol and water was used as a precursor to generate sol-gelation on the innerwall of the three-dimensional ordered macropores.The composite material was calcined to remove the polymer template to obtain the HPMC-Si O₂ with theoretically twelve macropores.Various steps of the experimental conditions were regulated,and a number of morphological hierarchical porous microcapsules were obtained.The material was loaded with gold nanoparticles.The catalytic reaction of p-nitrophenol was carried out to verify the performance of the support.3.Using water-soluble colloidal crystals as template,using 2-?trimethylsiloxy?ethyl methacrylate?TMSEMA?and cross-linking agent with bifunctional polysiloxane?PDMS?as precursors for polymerization.After removing the template and alcoholysis of the polymer,an amphiphilic hierarchical porous polysiloxane conetwork was obtained,and the amphiphilic polysiloxane was used as support loading the enzyme of CALB.The performance of the amphiphilic hierarchical porous polysiloxane conetwork for immobilizing and protecting the enzyme as a carrier was detected using catalytic model reactions.