Reversible Crosslinking of Polymer/Metal-Ion Complexes for a Microfluidic Switch

High Resolution Image Download MS PowerPoint Slide The importance of chitosan has been strongly emphasized in literature because this natural polymer could not only remove heavy metal ions in water but also have the potential for recyclability. However, reversible phase transition and its dynamics, which are highlighting areas of a recycle process, have not been studied sufficiently. Here, we present dynamic studies of the dissolution as well as the gelation of a physically crosslinked chitosan hydrogel. Specifically, a one-dimensional gel growth system and an acetate buffer solution were prepared for the precise analysis of the dominant factors affecting a phase transition. The dissolution rate was found to be regulated by three major factors of the pH level, Cu 2+, and NO 2 –, while the gelation rate was strongly governed by the concentration of OH – . Apart from the gelation rate, the…