Dispersion　of　SiO2　particles　in　aqueous　solutions　using　block　copolymers　remains　challenging,　particularly　due　to　degradation　in　highly　alkaline　environments　and　difficulty　in　achieving　high　solid　content.　Herein,　we　report　the　synthesis　of　an　anionic　block　copolymer,　poly(glyceryl　methacrylate-b-sodium　p-styrenesulfonate)　(PGGMA-b-PSSS),　containing　abundant　hydroxyl　groups,　via　reversible　addition-fragmentation　chain　transfer　(RAFT)　polymerization　of　sodium　p-styrenesulfonate　and　glycidyl　methacrylate　monomers.　The　hydroxyl　groups　in　PGGMA-b-PSSS　serve　as　anchoring　points,　producing　a　steric　hindrance　effect　between　SiO2　particles　by　interacting　with　silanol　groups　on　the　particle　surface.　Furthermore,　electrostatic　repulsion　from　the　poly(sodium　p-styrenesulfonate)　block　significantly　enhances　the　dispersibility　of　PGGMA-b-PSSS　in　aqueous　systems.　A　systematic　investigation　of　the　dispersibility　of　SiO2　particles　was　conducted　under　various　compositions　and　concentrations　of　PGGMA-b-PSSS　across　a　wide　alkaline　pH　range.　Our　results　show　the　effective　dispersion　of　sub-micron　and　micron-sized　SiO2　particles,　achieving　solid　contents　of　up　to　35　wt%　over　a　wide　pH　range　(3–13).　©　2025　Elsevier　B.V.