| A new, versatile concept is presented for the synthesis of Janus colloidosomes comprised of Laponite nanoclay armored polystyrene with anisotropie surface potential. Chemical modification of the colloidosomes was accomplished by cation exchange of sodium ions, originally present on the surface of the Laponite with various salts of modifying ions in the suspension. The zeta potential of the chemically modified and unmodified colloidosomes was compared. The maximum change in zeta potential was given by the calcium ions, Ca2+-adsorbed modified colloidosomes as compared to the unmodified sodium ions, Na+-adsorbed colloidosomes. Janus modification of the colloidosomes was performed by the Ca2+ ions and by templating the colloidosomes at a wax/water interface in a Pickering emulsion. Zeta potential measurements, XPS and optical microscopy were used to verify the successful chemical modification by cation exchange of Na+ for Ca2+ ions on one hemisphere of the Janus colloidosomes. |
