We demonstrate a facile method for preparing and developing colloidal structures through hydrogen-bonding interactions between colloidal stabilizers. When large polystyrene（PS） particles stabilized by poly（acrylic acid ）（PAA）（L-PSPAA） and small PS particles stabilized by poly（vinyl pyrrolidone）（PVP）（S-PSPVP） were simply mixed, raspberry-like particles were successfully formed via a heterocoagulation technique that utilizes hydrogen bonding between PAA and PVP. The surface coverage of L-PSPAA by S-PSPVP could be precisely controlled either by adding PVP homopolymer to the L-PSPAA particle dispersion or by varying the molecular weight of the stabilizers. Furthermore, we describe the preparation of Janus particles composed of two hemispheres with different stabilizers: PS phase stabilized by PAA and poly（methyl methacrylate）（PMMA） phase stabilized by PVP. Such particles were obtained using the solvent-absorbing/releasing method（SARM） applied to PS/PMMA composite particles with a core–shell structure. Transmission electron microscopy（TEM） images of ultrathin cross-sections revealed that the morphology transformed from a core–shell structure to a distinct Janus configuration after SARM treatment. We also demonstrate the facile formation of colloidal chains via hydrogen bonding interactions between different stabilizers. At pH 4.0, the Janus particles exhibited chain formation behavior. Interestingly, the structural evolution of these chains resembles the step-growth polymerization mechanism observed in molecular systems.
Hideto Minami (Thu,) studied this question.