PROBLEM TO BE SOLVED: To provide mesoporous silica particles whose pores are closed by covering the opening parts of the outer circumferential parts of the particles as the pores in the particles left without condensing the mesoporous silica particles, a dispersed liquid thereof and a method for producing the same.SOLUTION: Provided is a method for producing a mesoporous silica particle-dispersed liquid including: a step (A) where a silica source (a) is added to an aqueous solution including mesoporous silica particles in which the outer circumferential parts of the particles are covered with nonporous silica with a thickness of 3 to 30 nm, having the primary particle diameter of 30 to 300 nm and also having mesopores of 2 to 10 nm within the particles, a surfactant and a pH controller to produce a dispersed liquid of the silica particles having the mesopores in the particles, and thereafter, the surfactant is removed therefrom and a step (B) where a pH controller is added to the dispersed liquid of the silica particles with the mesopores obtained in the (A) step to control its pH to 8 to 10, thereafter, a silica source (b) is added, and treatment is performed at 20 to 90°C for 1 to 48 hr under stirring to cover the outer circumferential parts of the mesoporous silica particles.SELECTED DRAWING: None
