Sub-3 mu m silica core-shell particles (CSPs) were fabricated by a multilayer-by-multilayer method recently developed in our group. In this work, we report on methods to prepare and modify the properties of these CSPs by high temperature calcination, pore size enlargement under basic conditions, and rehydrolyzation in boiling water to make them more suitable as starting materials for preparation of HPLC columns. The chemical, physical and mechanical properties of these modified CSPs were characterized by scanning electron microscopy (SEM), infrared spectroscopy (IR), thermogravimetric analysis (TGA), and nitrogen sorption porosimetry. CSPs obtained after these treatments were observed to have the following properties: particle diameter similar to 2.7 mu m, shell thickness similar to 0.5 mu m, surface area similar to 200 m(2)/g, pore diameter similar to 10 nm (and almost no mesopores), pore volume similar to 0.5 cc/g, and Si-OH group surface concentration similar to 4 OH/nm(2). These properties are in line with those of commercially available sub-3 mu m CSP products. (c) 2014 Elsevier Inc. All rights reserved.