Structural strengthening of the nano porous silica films has been reported. The films were prepared with a base/acid two-step catalyzed TEOS-based sol-gel processing and dip-coating, and then baked in the mixed gas o... Structural strengthening of the nano porous silica films has been reported. The films were prepared with a base/acid two-step catalyzed TEOS-based sol-gel processing and dip-coating, and then baked in the mixed gas of ammonia and water vapor. The silica films were characterized with TEM, AFM, FTIR, spectrophotometer, ellipsometer, and abrasion test, respectively. The experimental results have shown that the films have a nanostructure with a low refractive index and can form an excellent scratch-resistant broadband anti-reflectance. The two-step catalysis noticeably strengthens the films, and the mixed gas treatment further improves mechanical strength of the silica network. Finally the strengthening mechanism has been discussed.展开更多
Hierarchical phases of the biomaterials can be used as template to transfer their intricate organization into biomimic inorganic solids. Herein, hierarchical mesoporous silica films with aligned pores have been templa...Hierarchical phases of the biomaterials can be used as template to transfer their intricate organization into biomimic inorganic solids. Herein, hierarchical mesoporous silica films with aligned pores have been templated by nanofibrillar alginic acid. An aqueous suspension of the alginic acid nanofibers was prepared by treating the brown seaweeds with sodium carbonate solution and subsequent precipitation in dilute hydrochloric acid. The alginic acid nanofibers of the organize into a hierarchical aligned phase in an acetic acid-sodium acetate buffer that was used to template silica-alginic acid composite films by evaporation induced self-assembly of alkoxysilane with nanofibrillar alginic acid. Calcination of the alginic acid template afforded hierarchical mesoporous silica glasses. Carbonization of the silica-alginic acid composites and subsequent etching the silica recovered mesoporous carbon supercapacitors.展开更多
Ordered mesoporous silica inorganic films were prepared in an acid solution at the air-solution interface by the biomimetic synthesis method, during which the hydrolysis of tetraethoxy silane (TEOS) was directed by ce...Ordered mesoporous silica inorganic films were prepared in an acid solution at the air-solution interface by the biomimetic synthesis method, during which the hydrolysis of tetraethoxy silane (TEOS) was directed by cetyltrimethyl ammonium bromide (CTAB) supramolecule self-assemblies. The effects of material ratio, pH and sampling time on the qualities of silica films were investigated. Fourier transform infrared (FTIR) spectrophotometer, High resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) were used to measure the biomimetic synthesized silica films extracted with 0.50 mol·L-1 hydrochloric acid ethanol solution. The results indicate that the structure of hexagonal ordered mesoporous is maintained, while the surfactant is removed effectively in mesoporous silica films.展开更多
基金the National Natural Science Foundation of China(No:69978017,20133040)Shanghai Key Subject Programme,Chinese Foundation of High Technology(2002AA842052)Shanghai Natural Science Foundation(02ZE14101)as well as Shanghai Nanotechnology Promotion Center(0159um039).
文摘 Structural strengthening of the nano porous silica films has been reported. The films were prepared with a base/acid two-step catalyzed TEOS-based sol-gel processing and dip-coating, and then baked in the mixed gas of ammonia and water vapor. The silica films were characterized with TEM, AFM, FTIR, spectrophotometer, ellipsometer, and abrasion test, respectively. The experimental results have shown that the films have a nanostructure with a low refractive index and can form an excellent scratch-resistant broadband anti-reflectance. The two-step catalysis noticeably strengthens the films, and the mixed gas treatment further improves mechanical strength of the silica network. Finally the strengthening mechanism has been discussed.
文摘Hierarchical phases of the biomaterials can be used as template to transfer their intricate organization into biomimic inorganic solids. Herein, hierarchical mesoporous silica films with aligned pores have been templated by nanofibrillar alginic acid. An aqueous suspension of the alginic acid nanofibers was prepared by treating the brown seaweeds with sodium carbonate solution and subsequent precipitation in dilute hydrochloric acid. The alginic acid nanofibers of the organize into a hierarchical aligned phase in an acetic acid-sodium acetate buffer that was used to template silica-alginic acid composite films by evaporation induced self-assembly of alkoxysilane with nanofibrillar alginic acid. Calcination of the alginic acid template afforded hierarchical mesoporous silica glasses. Carbonization of the silica-alginic acid composites and subsequent etching the silica recovered mesoporous carbon supercapacitors.
文摘Ordered mesoporous silica inorganic films were prepared in an acid solution at the air-solution interface by the biomimetic synthesis method, during which the hydrolysis of tetraethoxy silane (TEOS) was directed by cetyltrimethyl ammonium bromide (CTAB) supramolecule self-assemblies. The effects of material ratio, pH and sampling time on the qualities of silica films were investigated. Fourier transform infrared (FTIR) spectrophotometer, High resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) were used to measure the biomimetic synthesized silica films extracted with 0.50 mol·L-1 hydrochloric acid ethanol solution. The results indicate that the structure of hexagonal ordered mesoporous is maintained, while the surfactant is removed effectively in mesoporous silica films.
