Assembly of 1D Granular Structures from Sulfonated Polystyrene Microparticles

Abstract

Being able to systematically modify the electric properties of nano- and microparticles opens up new possibilities for the bottom-up fabrication of advanced materials such as the fabrication of one-dimensional (1D) colloidal and granular materials. Fabricating 1D structures from individual particles offers plenty of applications ranging from electronic sensors and photovoltaics to artificial flagella for hydrodynamic propulsion. In this work, we demonstrate the assembly of 1D structures composed of individual microparticles with modified electric properties, pulled out of a liquid environment into air. Polystyrene particles were modified by sulfonation for different reaction times and characterized by dielectric spectroscopy and dipolar force measurements. We found that by increasing the sulfonation time, the values of both electrical conductivity and dielectric constant of the particles increase, and that the relaxation frequency of particle electric polarization changes, causing the measured dielectric loss of the particles to shift towards higher frequencies. We attributed these results to water adsorbed at the surface of the particles. With sulfonated polystyrene particles exhibiting a range of electric properties, we showed how the electric properties of individual particles influence the formation of 1D structures. By tuning applied voltage and frequency, we were able to control the formation and dynamics of 1D structures, including chain bending and oscillation.

Core–Shell Particles: From Fabrication Methods to Diverse Manipulation Techniques

“…Self-assembly is significantly affected by particle size. At the micrometre scale, most self-assembly methods utilise aqueous dispersions of a charge-stabilised spherical polymer or silica beads [ 112 ]. At the nanoscale, most methods employ surfactant-coated particles dispersed in an organic solvent [ 113 ].…”

Core -Shell Particles: from Fabrication Methods to Diverse Manipulation Techniques

“…At the micrometre scale, most self-assembly methods utilise aqueous dispersions of chargestabilised spherical polymer or silica beads. [117] At the nanoscale, most methods employ surfactant-coated particles dispersed in an organic solvent. [118] Regardless of particle size, most self-assembly methods involve liquid media as this enables building blocks to adopt the various configurations.…”