One-pot two-step production of nano-CaCO3 with tunable Janus balance decorated by self-crosslinked admicelle of conjugated linoleate

Background: In mass production of Janus nanoparticles, tunable Janus balance, nanoscale decoration, environmental and biological compatibility, and response to environmental stimuli are challenges. Methods: By manipulating the self-assembly and self-crosslinking of sodium conjugated linoleate (SCL), we established a facile one-pot synthesis with two-step addition of SCL under wax protection on partial surface of the microspheres to synthesize CaCO3 Janus nanoparticles with above features simultaneously. Significant findings: The self-crosslinked admicelle (SCA) of SCL decorated on the nano-CaCO3 surface to produce SCA-CaCO3 Janus nanoparticles, and their Janus balance is tunable by simply regulating the primary SCL dosage in the preparation of molten wax emulsions. Afterwards, O/W Pickering emulsions are stabilized by 0.25 wt% of the selected SCA-CaCO3 Janus nanoparticle with a proper Janus balance at primary SCL dosage of 60 mg & sdot;L- 1; the obtained high internal phase emulsion is reversibly switchable by pH or CO2-N2 triggers. This strategy of onepot two-step production of Janus particles may provide a facile mass production tool to create hierarchical Janus structures for various inorganic nanoparticles with different sizes and chemical compositions, endowing variable Janus surfaces with tunable Janus balance, providing a nanoscale SCA decoration layer of SCL with biocompatibility, environmental friendliness and multi-stimuli responses.