Smart Conducting PANI/P(St-NIPAM) Particles and Their Switchable Conductivity

Particles with circumstance-responsive conductivity have appealing performance in constructing sensors. Here, “smart” conducting polyaniline-doped poly(styrene-co-N-isopropyl acrylamide) composite spheres, i.e. PANI/P(St-NIPAM) particles, are reported. A series of PANI/P(St-NIPAM) particles can be prepared with different ratios of N-isopropyl acrylamide to monomers, i.e. N/M ratios. With the improved N/M ratios in polymerization, the amount of polyaniline (PANI) incorporating in the produced particles increased, resulting in an enhanced conductivity. With the improved N/M ratios, the hydrodynamic diameters of PANI/P(St-NIPAM) particles increased at low temperature whereas decreased at high temperature; resulting in the enhanced volume-change ability with the increasing poly(N-isopropyl acrylamide) (PNIPAM) content in particles. Depending on the temperature-induced volume change, these particles exhibit “smart” conductivity in a home-made device, in which these particles can be used as a temperature-respon...