The present invention relates to core shell silica particles, wherein each core shell silica particle comprises a silica core, and a surface of the silica core is etched with metal silicate, the core shell silica particles prepared by: i) admixing an amount of silica particles in water with an amount of a base, wherein the base comprises a monovalent metal ion, to produce core shell silica particles, each core shell silica particle comprising a silica core, and a surface of the silica core etched with a silicate of the monovalent metal ion and ii) reacting the core shell silica particles formed in step i) with a metal salt comprising a second metal ion, to form core shell silica particles comprising silicate of the second metal ion on the surface of the silica core.本發明有關一種芯殼二氧化矽顆粒,其中各芯殼二氧化矽顆粒包括二氧化矽芯,二氧化矽芯表面被金屬矽酸鹽蝕刻,製備芯殼二氧化矽顆粒係藉由:i)將定量二氧化矽顆粒於水中與定量鹼摻混,其中鹼包括單價金屬離子,製造芯殼二氧化矽顆粒,各芯殼二氧化矽顆粒包括二氧化矽芯,二氧化矽芯表面被單價金屬離子之矽酸鹽蝕刻,ii)使步驟i)形成之芯殼二氧化矽顆粒與包括第二金屬離子之金屬鹽反應,形成包括第二金屬離子矽酸鹽於二氧化矽芯表面之芯殼二氧化矽顆粒。
