Supercritical carbon dioxide is used to generate macroporosity in an inverse vulcanised polymer, which shows excellent promise for enhanced mercury capture and filtration from water.

Dispersion polymerization is a well‐established method of producing polymer particles that are easily handled and processed. With careful choice of reaction conditions this technique can yield well defined, spherical particles for a wide range of applications. The use of supercritical carbon dioxide (scCO2) as a reaction medium offers a route to performing these syntheses without excessive use of volatile organic solvents and minimizes work‐up and disposal steps. However a significant drawback has been the fact that up till now the control of particle size and morphology from CO2 have been limited. This study presents control of particle size and morphology over an unprecedented range for a single stabilizer in scCO2 by coordinating a few simple parameters to tailor the conditions toward different sizes. Further, this study introduces the novel approach in scCO2 of using delayed monomer addition which allows considerable reduction of the batch‐to‐batch variability as well as reduced agglomeration between particles.

Well-defined, strongly coloured and electrophoretically active poly(methyl methacrylate) microparticles in one-pot, via dispersion polymerisation in supercritical carbon dioxide and dodecane.

Along with their DNA binding ability, the secondary amines in linear polyethylenimine (L-PEI) units can also act as a reaction platform to introduce new functionalities. This renders the possibility to make a plethora of copolymers without the burden of new monomer synthesis. In this work the modification of the secondary amines of L-PEI, in either a pure L-PEI polymer or in a PEtOx-PEI copolymer, with supercritical CO 2 is reported. This reaction between a secondary amine and CO 2 results in formation of a carbamate, a fluorescent zwitterionic group. This gives a facile route to fluorescent carbamatefunctionalzied L-PEI and PEtOx, thereby expanding the chemical toolbox of both polymers. In depth analysis of the obtained polymers by 2D nuclear magnetic resonance spectroscopy revealed that, besides the expected carbamate groups, there were also some side reactions leading to the irreversible introduction of (cyclic) urea groups and partial cross-linking of the L-PEI. Altogether, this work introduces a new simple tool for the preparation of fluorescent L-PEI and PEtOx, while also shedding light on the occurrence of side reactions in PEI-based materials for CO 2 sorption.