In an embodiment, a porous composite particulate material includes a plurality of composite particles. Each composite particle includes an acid-base-resistant core particle at least partially surrounded by one or more layers of acid-base-resistant shell particles. The shell particles are adhered to the core particle by a polymeric layer. The shell particles and/or core particles may be made from an acid-base-resistant material that is stable in harsh chemical conditions. For example, the shell particles and/or core particles may be made from diamond, graphitic carbon, silicon carbide, boron nitride, tungsten carbide, combinations of the foregoing, or other acid-base-resistant materials. The porous composite particulate materials disclosed herein and related methods and devices may be used in separation technologies, including, but not limited to, chromatography, and solid phase extraction.