Guojun Lv,Yan Chen,Xuyang Zou,Jiangzhang Wang,Tao Wang,Xubin Zhang,Fumin Wang
There are few reports concentrated on the interactions between lipophilic surfactants and hydrophobized hollow TS-1 zeolite particles in the stabilization of emulsions. In this study, hydrophobized hollow TS-1 zeolite particles were synthesized and applied as emulsifier to stabilize the W/O Pickering emulsions employing cyclohexanone and water, and the influence of addition of lipophilic Span 80 on the stability of the W/O Pickering emulsions was systematically studied. Surprisingly, a phase inversion was induced by simply changing the Span 80 concentration. At fixed concentration of TS-1 zeolite particles (2 wt%), emulsions are water in oil (W/O) when the concentration of Span 80 is lower than 0.5 mM. Then the emulsions invert to oil in water (O/W) when the Span 80 concentration is between 1 mM and 8 mM. In this process, different emulsifiers dominate the composition of the interfacial layer, and the emulsion type is correspondingly controlled. When Span 80 concentration is lower than 0.5 mM, hydrophobized hollow TS-1 zeolite particles are in domination, and W/O emulsions are obtained. At Span 80 concentration of 1–8 mM, the emulsions are stabilized mainly by Span 80, and the emulsion type is O/W.
Yi Zhai,Fumin Wang,Xubin Zhang,Guojun Lv,Zhiguo Zhu,Kaiwei Wang,Zhibo Xu,Linfang Jiang
Realizing anatase-free hollow TS-1 with a controllable titanium micro-environment via dissolution-recrystallization for diverse catalytic reactions remains a great challenge due to the insufficient comprehension of dissolution-recrystallization mechanism, high cost and environmental issues. Here, anatase-free hollow TS-1 was economically synthesized via mother-liquor-induced dissolution-recrystallization, realizing the controllable micro-environment and spatial distribution of titanium. A novel kinetic-thermodynamic co-regulatory pathway was unveiled for the first time to describe the magical reversible varying of titanium micro-environment during the dissolution-recrystallization process (dissolution-reinsertion-secondary dissolution). Thermodynamically, temperature and liquid-to-solid ratio cause the formation of anatase and unsaturated silicon, and the unsaturated silicon species (Q1 and Q2) determine the subsequent capture and re-insertion of anatase. Original unsaturated silicon species in the mother liquor endow it with a unique function to further facilitate the elimination of anatase. Kinetically, temperature determines the dynamic progress of the reversible process such as evolution speed and deposition priority of titanium and silicon species. Multi-factor dynamic constraints directly determine the micro-environment, spatial distribution and content of titanium. This provides a new perspective for predicting and synthesizing hollow heteroatomic zeolites with ideal heteroatom micro-environments. Unique surface properties and diverse titanium micro-environments endow hollow TS-1 with superior mass-transfer abilities to exhibit different activities in 1-hexene epoxidation and phenol hydroxylation.
危险品化学品经营许可证（带存储）