Preparation And Properties Of Porous Silica Series Materials

Fluorescent mesoporous silica nanoparticles （FMSN） with radialmesochannels were synthesized. The growth process of FMSN was studied.TEM results indicated that with the extension of reaction time, the effect ofsilica connectors between particles was weakened, resulting in theformation of silica nanoparticles. The optimal reaction time was3h. Theeffects of fluorescent groups （APTES-SA,Aminopropyltriethoxysilane-Salicylic Acid） and catalyst （TEA,Triethanolamine） on the FMSN were investigated, suggesting that withdecreasing the molar ratio of TEOS （Tetraethyl Orthosilicate）/TEA, theparticle size of FMSN increased. Meanwhile, as the addition of APTES-SA,the particle size increased and the particles became more compaction. Buttoo much APTES （APTES-SA/TEOS=0.4） resulted in the formation ofwhole piece of silica. The fluorescent properties of FMSN were studied bythe absorption and emission spectra, revealing that all fluorescent groupswere linked to the silica particles.The hollow porous silica particles with radially oriented porous wall（ROPHS） were synthesized at room temperature by an instant method. Theeffect of DMF （N,N-dimethylformide） on the formation of ROPHS wasstudied. When zero or small amount of DMF was added, pure solid silicananoparticles were obtained by TEM. However, with the increase of theaddition of DMF, more hollow silica particles were formed. Moreover, thethickness of the wall kept the same in each condition. The effects ofdifferent reaction time on the growth process of ROPHS were studied,indicating that hollow porous silica can be formed instantly, only in0.5h. At the same time, the solid mesoporous silica was not formed. With theincrease of reaction time, the thickness of the porous wall increased. Whenchanging stirring to sonication, the total size and the hollow phase size ofporous silica decreasd. TEM observation showed that Au and Fe3O4nanoparticles could be totally trapped into porous silica to form core-shellstructure, which has the potential application in drug release.ZSM-5, silicalite-1and zeolite Y materials were synthesized and itsCO₂adsorption performance was carried out by TGA method. HomogenousZSM-5crystals were synthesized by hydrothermal treatment and treated byion exchange. Homegeneous silicalite-1particles were synthesized byreflux heating treatment. Pure zeolite Y material was synthesized andtreated by ion exchange. According to the TGA results, CO₂pickupcapacities of ZSM-5（AS2）, Na（Ⅰ）-ZSM-5（AS2）, Na（Ⅱ）-ZSM-5（AS2）,Na（Ⅰ）-CBV2314, Na（Ⅱ）-CBV2314, Na（Ⅱ）-CBV8014, silicalite-1-500-10,Na（Ⅰ）-Y, Na（Ⅱ）-Y, La（Ⅰ）-Na（Ⅰ）-Y, Mg（Ⅰ）-Na（Ⅰ）-Y and NaY are0.5%,2.3%,5.0%,1.9%,2.5%,3.6%,3.4%,3.6%,4.0%,2.0%,2.5%and3.4%,respectively. Among all zeolite samples studied in this work, CO₂pickupcapacity of Na（Ⅱ）-ZSM-5（AS2） was the highest.