Size-Controlled Synthesis of Monodispersed Poly(3-mercaptopropylsilsesquioxane) Microspheres by a Two-Step Sol–Gel Method

Abstract

A two-step acid−base catalyzed sol−gel method has been used to prepare monodispersed poly(3mercaptopropylsilsesquioxane) (PMPSQ) microspheres. Initially, the hydrolysis of 3-mercaptopropyltrimethoxysilane was catalyzed by hydrochloric acid in an aqueous medium, and then the addition of ammonium hydroxide initiated the condensation of hydrolysate. The formation process of PMPSQ microspheres was characterized by field emission scanning electron microscopy and 29 Si NMR. The formation mechanism of the monodispersed microspheres was also discussed. Through this method, monodispersed PMPSQ microspheres with a high yield were achieved and the particle size could be adjusted by changing the precursor concentration.

Facile Fabrication of Lilium Pollen-like Organosilica Particles

“…According to our previous work, the particle size of organosilica particles will decrease with the decline of the concentration of the silane precursor. 25,26 Nonspherical organosilica particles also follow this rule. As we can see from Figure 7, the particle size decreased with the reduction of silane precursors in the whole system.…”

Synthetic strategies for nonporous organosilica nanoparticles from organosilanes

“…Such reactions are usually conducted in a hydroalcoholic media (typically an ethanol/water mixture), [13][14][15][16][17][18][19][20][21][22][23] in which a homogeneous precursor solution can be formed initially. In addition, the syntheses can also be carried out in pure aqueous media, [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42] or other media. [43][44][45][46][47][48][49][50][51][52] Perhaps the most widely studied organosilane precursor is MPTMS since its thiol group is a versatile functional group that has various potential applications, ranging from adsorbents for toxic heavy metals ions to binders for nanoparticles and immobilizing agents for oligonucleotides and proteins.…”

Biocides and techniques for their encapsulation: a review

“…In addition, the speed of the solÀgel process may be tuned via the use of both kinds of catalysts (dual catalyst route). 85,86 Nanoparticles may be generated by specific conditions described in the Sto ¨ber route. 87,88 Nonhydrolytic routes are also possible.…”