Dual Stimuli-Responsive “Mushroom-like” Janus Polymer Particles as Particulate Surfactants

Abstract

"Mushroom-like" Janus poly(methyl methacrylate) (PMMA)/poly(styrene-2-(2-bromoisobutyryloxy)ethyl methacrylate)-graft-poly(2-(dimethylamino)ethyl methacrylate) (PDM) particles synthesized in our previous report were applied as particulate surfactants. The PDM moiety at the one side of the Janus particles reversibly exhibited the volume phase transition in response to pH and temperature in an aqueous medium; that is, the surface property of the Janus particles comprising both PDM and PMMA reversibly changed between amphiphilic and hydrophobic based on the nature of PDM. Consequently, 1-octanol-in-water emulsion droplets stabilized by the amphiphilic Janus particles coalesced in the alkaline region and at 60 degrees C around neutral pH because of desorption of the hydrophobized Janus particles from the interface to the oil phase.

Porous polymer particles—A comprehensive guide to synthesis, characterization, functionalization and applications

“…A novel or improved technique [453][454][455] inheriting abilities of microfluidics but overcoming its problems such as tedious device preparation and scalability would be another renaissance for particle production. Finally, unique mechanical, packing and assembly properties of nonspherical particles are already drawing attention [6,85,161,[453][454][456][457][458][459][460][461][462][463][464][465][466][467][468] but the effect of porosity on such regular nonspherical particles is still waiting to be further exploited.…”

Asymmetric Colloidal Janus Particle Formation Is Core-Size-Dependent

“…17 A common route of synthesis for Janus particles is using electrostatic assembly 18−23 and spontaneous formations. [6][7][8][9][10]24 This method is frequently used to make hierarchical templates that can then be selectively coated to make asymmetric colloidal structures. 18−23 Such templates are usually synthesized by mixing in the same solution a core particle of one charge and satellites of the opposite charge.…”

Light-Triggered Responsive Janus Composite Nanosheets

“…8 Dually pH-and temperature-responsive mushroom-like Janus polymer particles are synthesized which can serve as a dual responsive particulate surfactant. 9 Compared with Janus particles, Janus nanosheets are more efficient to stabilize emulsions due to their highly confined rotation at interfaces. 10 We have recently developed a facile approach to large scale production of silica Janus nanosheets by crushing the corresponding silica Janus hollow spheres.…”