Scalable synthesis of ultrasmall hybrid silica colloidal particles through balanced solvophobic interaction and electrostatic repulsion

Ultrasmall silica colloid particles (SCPs) show broad applications in various fields, including cosmetics, paint, medicine, and electronics. However, the precise and scalable synthesis of ultrasmall SCPs remains challenging. This study introduces a facile polymer-based strategy for the synthesis of ultrasmall SCPs through the synergistic utilization of solvophobic interactions and electrostatic repulsion. The size of SCPs can be efficiently modulated by the ratio between solvophilic and solvophobic segments within random copolymers. This approach allows for producing SCPs with a diameter of down to 9.6 ± 1.7 nm and a solid content of up to 9.8%. Furthermore, amphiphilic SCPs were obtained by introducing PEO blocks into copolymer templates and modifying with long carbon chain silane coupling agent.