Fabrication of polymeric-Laponite composite hollow microspheres via LBL assembly

Hollow structure microspheres with composite polymeric-Laponite shells were prepared by electrostatic self-assembly of Laponite on the polymeric hollow microspheres in this work. The multilayer hydrophilic core/hydrophobic shell polymer latex particles containing carboxyl groups inside were first synthesized via seeded emulsion polymerization, followed by alkali treatment, generating polymeric hollow microspheres. Then, polyethyleneimine (PEI) and Laponite were alternately electrostatic adsorbed on the prepared polymeric hollow microspheres to form polymeric-Laponite composite hollow microspheres. It was indicated that the morphology of alkali-treated microspheres could be tuned through simply altering the dosage of alkali used in the post-treatment process. Along with the increasing of the coating layers, the zeta potential of microspheres absorbed PEI or Laponite approximately tended to be constant respectively, and the thickness of Laponite layer around the hollow microspheres increased clearly, getting more uniform and homogenous. Furthermore, the corresponding polymeric-Laponite hollow microspheres showed high pressure resistance ability compared to the polymeric hollow microspheres.