| 摘要 |
<p>The invention is directed to a process for the preparation of the silica spheres comprising the following steps
a) Providing silica nanoparticles modified with a silane according to the formula (CH 3 ) n SiX 4-n wherein X is a hydrolysable group and n is 1, 2 or 3,
b) Dispersing the modified silica nanoparticles in water to form an aqueous dispersion with a pH between 8.5 and 10 or between 2 and 4, wherein the concentration of the modified silica nanoparticles is at least 0.5 wt%,
c) Mixing a hydrophobic liquid comprising polyethoxysiloxane (PEOS) with the aqueous dispersion to form a reaction mixture, wherein the amount of polyethoxysiloxane in the hydrophobic liquid is between 30 and 90 wt% based on the combined weight of the hydrophobic liquid and the polyethoxysiloxane,
d) Emulsifying the reaction mixture to prepare an oil-in-water type Pickering emulsion and
e) Allowing the PEOS in the emulsion to hydrolyze and condense at least 1 hour to form the silica spheres.</p> |
