Temperature‐Triggered Capture of Dispersed Particles Using a Laponite‐Poly(NIPAM) Temperature‐Responsive Surface

Abstract

In this study a new method is investigated that enables a conductive surface to be modified so as to capture dispersed particles when the temperature is increased. Poly(NIPAM) (NIPAM is N‐isopropylacrylamide) was grafted from electrodeposited Laponite RD particles using surface‐initiated atom transfer radical polymerization (ATRP) to give a temperature‐responsive surface. This was used to capture dispersed polystyrene particles. In the first part of the study the conditions used to electrodeposit Laponite onto a carbon foam electrode were determined. The ability of the temperature‐responsive surface to capture dispersed polystyrene particles was investigated between 20 and 50°C. Temperature‐triggered particle capture was reversible or irreversible depending on the conditions used during ATRP. A high surface concentration of poly(NIPAM) on the particle electrodes is believed to increase the extent of polystyrene particle capture and also reversibility. A theoretical analysis in terms of interaction energy–distance curves is presented for the capture behavior. It is concluded that the temperature‐responsive surface has both electrostatic and steric contributions to the total interaction energy. The steric component (which originates from poly(NIPAM)) is temperature‐dependent and provides the basis for temperature‐triggered particle capture.