Fabrication of calcined hierarchical porous hollow silicate micro-size spheres via double emulsion process

► Increasing sodium polymethacrylate into the double emulsion aqueous solution a macroporous shell wall hollow silicate microsphere (PHSM) appears. ► Wherein, pore size increase eventually decreases the surface area. ► With the aid of ~ 8200 rpm (emulsification) and N2 filtration followed by calcination, form stable PHSM micro-size (7 to 12 μm) particles.