Engineered Latex Particles Using Core-Shell Emulsion Polymerization: From a Strawberry-like Surface Pattern to a Shape- Memory Film

Structured colloidal particles with diverse morphologies have attracted great attention due to their excellent designability and multiple application ranges. However, morphological control of colloidal particles in a precise, highly efficient way is difficult owing to the complicated dynamic assembly and arrangement of building components at the nanoscale. This article proposes a simple strategy to construct structured colloidal particles with diverse morphologies using core-shell (CS) emulsion polymerization. The CS system is developed using PVAc-based polymers as cores and PS based polymers as shells, in which acrylonitrile (AN) functions as a mediating linker distributed on the core surface. By precisely adjusting the mobility of the shell polymer chains and the rearranged AN-active sites on the core surface, a transformation of particle morphology, from a partially-covered strawberry-like surface pattern over a spherical lobed surface to a spherical homogeneously merged shell, is achieved. Moreover, a latex film formed from typical strawberry-like PVAc-AN/PS latex particles exhibits a rapid, highly efficient triple shape-memory capability when either bending or stretching deformation is applied under optimized programmable conditions. This study provides valuable information for creating various morphological particles for utilization in colloidal assemblies and functional films.