Evaporation-driven Supraparticle Synthesis by Self-Lubricating Colloidal Dispersion Microdrops

초록

The surface-templated evaporation-driven(S-TED) method that usesliquid-repellent surfaces has attracted considerable attention forits use in fabricating supraparticles of defined shape, size, andporosity. However, challenges in achieving mass production have impededthe widespread adoption of the S-TED method. To overcome this limit,we introduce an evaporation-driven "multiple supraparticle"synthesis by drying arrays of self-lubricating colloidal dispersionmicrodrops. To facilitate this synthetic method, a hydrophilic micropatternis prepared on a hydrophobic substrate as a template. During the removalof the substrate out of a dispersion, liquid drops are trapped andgenerate a microdrop array. To produce supraparticles, the contactlines of the trapped drops must be able to recede freely during evaporation.However, hydrophilic micropatterns induce strong contact line pinningfor microdrops that hinders supraparticle formation. Herein, we solvethis contradiction by employing an Ouzo-like colloidal dispersion,where we can control the wettability of the drop trapping domain.The self-lubrication effect provided by the Ouzo-like solution enablessmooth movement of the drops' contact lines during evaporation,thereby resulting in the successful fabrication of supraparticle arrayseven within the trapping domain. This strategy offers a promisingand scalable approach for large-scale evaporation-driven supraparticlesynthesis with a potential for extension to various primary colloidalparticles, further broadening its applicability.

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