Synthesis And Application Of Soft Colloids With Well Controlled Softness

Recently, there is a growing interest in synthesis of soft-colloidal particles in softmatter research field. Soft colloids possess intriguing properties of both polymers andconventional hard colloids, including deformation, stimuli-responsiveness and tunablerheological properties. These properties are closely related with softness of colloids.Therefore, soft colloids have found wide applications in tunable photonic structures,drug release, stimuli-sensing and new model systems to mimic the phase behavior ofatoms and molecules.Colloids with various softness have not been explored extensively and there havebeen only a few reports on the preparation of such colloids, including:1) core-shellpolymerization;2) microfluidics and3) emulsion polymerization with differentcross-linkers. Nevertheless, these techniques have some drawbacks, including:sophisticated procedures as in core-shell polymerization; low-throughput productionand large particle size, usually in microfluidics fabrication, and lack the ability ofprecisely control the softness and/or the monodispersity of the colloids. In a word,there is an emergency need to design the new method to fabricate different softcolloidal particles.In this paper, we present a novel and easy-to-implement method to prepare colloidswith precisely controlled softness. Our method includes the following two steps:(i)Monodisperse silicon oil droplets are prepared by a base-catalyzed hydrolysis andcondensation of silane.(ii) The as-obtained silicon oil droplets are polymerized withthe different amounts of initiator, forming uniform colloids with controlled softness. Itwas found that varying the mixing ratio of TPM and NH4OH had a noticeable effect on the final size soft colloids, whereas their monodispersity was not affected. In addition,the soft colloids contain functional double bonds on their surface and thereforeproviding the possibility to introduce desired monomer/polymer onto the surface.Here, we explored the application of various softness colloidal particles. The resultsshowed that the softness of particle can greatly affect the uniformity of coating afterthe colloidal suspension is dried, and more uniform coatings can be obtained by usingof the soft particle. In addition, the soft particles can suppress the coffee-ring effect ofhard colloidal particles.In summary, we have presented a novel method to prepare polymeric colloids withwell controlled softness. The soft colloids contain functional double bonds on theirsurface. In addition, soft colloidal particles can suppress the coffee-ring effect.Therefore it provides the possibility to introduce desired monomer/polymer onto thesurface and practical applications. For example: tissue-engineering, paint and coatingindustries.