Methods for preparing high loading core shell silica (CSS) particles, or CSS particles having a relatively greater amount of surface active silicate groups than CSS particles prepared according to conventional methods is provided. The method may include contacting silica particles with a base having a first metal ion to produce core shell silica particles. Each of the core shell silica particles may include a silica core and a silicate of the first metal ion etched on a surface of the silica core. The method may also include contacting each of the core shell silica particles having the silicate of the first metal ion with an acidic aqueous solution including a metal salt having a second metal ion to produce core shell silica particles including the silica core and a silicate of the second metal ion on the surface of the silica core.