Hydrolysis of silica sol-gel precursors

Abrasive-polishing agent, use of silica gels and precipitated silicas, 625 Abrasive powder, preparation, 426, 427f Acetic acid, catalysis of silica sol-gel precursor hydrolysis, 406, 407t, 408/ Acid-neutralization manufacturing method for silica sol, procedure, 53, 54/... 

Chapter 48 The Chemistry of Hydrolysis and Condensation of Silica Sol-Gel Precursors. 637... 

Generally, two common methods, the Stober method and the reverse microemulsion method are used for synthesis of silica nanoparticles. As derivatives of a sol-gel process, both methods involve hydrolysis of a silicon alkoxide precursor to form a hydroxysilicate followed by polycondensation of the hydroxysilicate to form a silica nanoparticle [44]. 

Starting with acid-catalyzed hydrolysis and condensation (step 1) of the silica precursor (tetraethoxysilane, TEOS), the viscous product (poly(ethoxy)siloxane, PES) is converted into silica hydrogel beads in a stirring process under basic conditions (step 2). Both the viscosity of the sol-gel derived PES and the stirring speed directly influence... 

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