New vinyl ester copolymers as stabilisers for dispersion polymerisation in scCO2

Investigation on modified polyether as an efficient CO2 thickener

Based on the CO₂-philic silicon group and the CO₂-phobic aryl group, silicon modified polyether exhibits both high solubility in carbon dioxide and a high thickening ability toward CO₂.

Hydrocarbon based stabilisers for the synthesis of cross-linked poly(2-hydroxyethyl methacrylate) particles in supercritical carbon dioxide

Novel polymeric stabilisers were designed for the development of an environmentally-friendly process to prepare well-defined cross-linked particles of poly(2-hydroxyethylmethacrylate) (PHEMA).

Mild synthesis of poly(HEMA)-networks as well-defined nanoparticles in supercritical carbon dioxide

Free-radical dispersion polymerisation of 2-hydroxyethyl methacrylate was carried out in supercritical carbon dioxide (scCO₂) in the presence of stabilisers based on polyethylene oxide (PEO) and poly(heptadecafluorodecyl acrylate) (PFDA). Different architectures of copolymers (random, palm-tree and diblock) were tested for their surface tension, cloud point and as a stabilising agent. The diblock architecture was found to be the best candidate resulting in poly(HEMA) spherical particles with a size of 316 nm. Furthermore, the effect of the CO₂-phobic block (PEO) in the diblock architecture was investigated by using three different chain lengths (1000, 2000, 5000 g mol^-1). By optimizing the stabiliser composition and structure, mild reaction conditions have been identified allowing us to obtain well-defined spherical cross-linked poly(HEMA) particles with a mean diameter of unprecedented low size (216 nm) at a temperature as low as 35 °C.

A photocleavable stabilizer for the preparation of PHEMA nanogels by dispersion polymerization in supercritical carbon dioxide

Synthesis of PHEMA nanogels stable in water by a scCO₂ process.

Structure-Property Relationships in CO2-philic (Co)polymers: Phase Behavior, Self-Assembly, and Stabilization of Water/CO2 Emulsions

This Review provides comprehensive guidelines for the design of CO2-philic copolymers through an exhaustive and precise coverage of factors governing the solubility of different classes of polymers. Starting from computational calculations describing the interactions of CO2 with various functionalities, we describe the phase behavior in sc-CO2 of the main families of polymers reported in literature. The self-assembly of amphiphilic copolymers of controlled architecture in supercritical carbon dioxide and their use as stabilizers for water/carbon dioxide emulsions then are covered. The relationships between the structure of such materials and their behavior in solutions and at interfaces are systematically underlined throughout these sections.

Enhanced Solubility of Polyvinyl Esters in scCO2 by Means of Vinyl Trifluorobutyrate Monomer

The novel monomer, vinyl trifluorobutyrate (VTFBu), when polymerized in a controlled fashion by RAFT/MADIX polymerization with a xanthate transfer agent, yields poly(vinyl ester)s with improved solubility in supercritical carbon dioxide. The thermodynamic parameters controlling the solubility of VTFBu/vinyl acetate statistical copolymers are discussed based on ab initio calculations, glass transition temperatures of the copolymers, and surface tension measurements. The enhanced solubility of this new class of CO₂-philic polymer combined with its good chemical stability render it attractive for the preparation of next-generation macromolecular surfactants for the formation of water-scCO₂ emulsions.

Emulsion-templated poly(acrylamide)s by using polyvinyl alcohol (PVA) stabilized CO2-in-water emulsions and their applications in tissue engineering scaffolds

Commercially available polymer i.e., polyvinyl alcohol (PVA), is used to produce stable CO₂/water emulsions. These emulsions were then used to produce emulsion templated hierarchically porous materials with interesting tissue engineering applications.