METHOD FOR PRODUCING HOLLOW SILICA NANOPARTICLE

PROBLEM TO BE SOLVED: To provide a method for producing hollow silica nanoparticles having a primary grain size of 100 nm or less.SOLUTION: The method for producing hollow silica nanoparticles having a primary grain size of 100 nm or less includes following steps (1) and (2). (1): A water dispersion of an associated body of a two chain-type cationic surfactant (A) is prepared by subjecting an aqueous solution of the two chain-type cationic surfactant (A) to ultrasonic irradiation at a temperature of a Krafft point of the two chain-type cationic surfactant (A) or higher. (2): The water dispersion of the associated body of the two chain-type cationic surfactant (A) obtained in the step (1) and an alkoxysilane (B) are mixed with each other at the temperature of the Krafft point of the two chain-type cationic surfactant (A) or lower.