Controllable preparation of thio-functionalized composite polysilsesquioxane microspheres in a microreaction system

Controllable preparation of monodispersed composite polysilsesquioxane microspheres (CPSQs) with scalability is required but difficult to realize in a conventional stirred batch reactor because of the reactors' poor mixing performance and scaling-up effects. A new semi-continuous microreaction system integrating a microreactor with a stirred batch reactor was developed for the synthesis of monodispersed thio-functionalized CPSQs by employing a two-step sol-gel method. Methyltrimethoxysilane and (3-mer captopropyl)trimethoxysilane were used as silicon sources. The effects of the synthesis variables were systematically studied. The particle size could be adjusted between several hundreds of nanometers and several micrometers with a narrow size distribution (the coefficient of variation was <10%), and the sulfhydryl group (-SH) concentration reached 14.13 at.%. Compared with the batch reactor, the semi-continuous microreaction system showed higher synthesis reproducibility and higher potential for the large-scale production of CPSQs. (c) 2022 The Society of Powder Technology Japan. Published by Elsevier BV and The Society of Powder Technology Japan.

Automated summary

In this study, a new semi-continuous microreaction system was developed to achieve controllable preparation of monodispersed composite polysilsesquioxane microspheres (CPSQs) with scalability. The system showed higher synthesis reproducibility and higher potential for large-scale production compared to conventional batch reactors.