文献类型：期刊文献

英文题名：Unraveling Particle Size and Roughness Effects on the Interfacial Catalytic Properties of Pickering Emulsions

作者：Li, Yao[1,2];Zhao, Guolin[1,2];Hong, Bing[1];Zhao, Shuangliang[2];Han, Xia[2];Pera-Titus, Marc[1]

机构：[1]CNRS Solvay, Ecoefficient Prod & Proc Lab E2P2L, UMI 3464, Shanghai 201108, Peoples R China;[2]East China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China

年份：2020

卷号：599

外文期刊名：COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS

收录：;EI(收录号：20201908635627);WOS:【SCI-EXPANDED(收录号:WOS:000561644200007)】；

基金：CNRS and Solvay are acknowledged for funding. This work was partially supported by the National Natural Science Foundation of China (Nos. 21808056, 21878078), and the 111 Project of China (No. B08021).

语种：英文

外文关键词：Pickering Interfacial Catalysis; emulsion; amphiphilic silica; acetalization; particle size; surface roughness

摘要：Pickering Interfacial Catalysts (PIC) has emerged as a powerful concept for designing multiphasic reactions between immiscible reagents using heterogeneous catalysts. Nonetheless, systematic studies addressing the influence of the particle self-assembly on the catalytic properties are scarce. To fill this gap, here we studied the effect of the particle size and surface roughness of catalytic nanoparticles on the reactivity of non-aqueous immiscible systems in the presence of Pickering emulsions. To this aim, we prepared a library of amphiphilic silica nanoparticles with the same surface properties and bearing catalytically active acid centers, but showing variable particle sizes in the range 90-460 nm and surface roughness. The nanoparticles were characterized in detail using different techniques, including acid-base titration, TGA, TEM and DLS. The silicas were tested in the biphasic acetalization reaction of dodecanal and ethylene glycol. The catalyst productivity was enhanced for smaller sized nanoparticles ( < 210 nm) as a result of the formation of more stable ethyleneglycol-in-dodecanal emulsions along with larger interfacial surface areas and a more compact interfacial self-assembly of particles. By contrasting the experimental emulsification results with dissipative particle dynamics simulations combined with the generalized Young equation, the particle-size dependence of ethyleneglycol-in-dodecanal emulsions could be explained by a stabilizing role of the line tension. The surface roughness of the particles was found to be detrimental for emulsion stability, but its negative effect was largely compensated by the stabilizing role of the line tension, especially for smaller particles. Overall, the particle size exerts a more prominent effect than the surface roughness on emulsion stability and interfacial catalysis for the ethyleneglycol/dodecanal system.