Supercritical carbon dioxide: a solvent like no other

Abstract

SummarySupercritical carbon dioxide (scCO2) could be one aspect of a significant and necessary movement towards green chemistry, being a potential replacement for volatile organic compounds (VOCs). Unfortunately, carbon dioxide has a notoriously poor solubilising power and is famously difficult to handle. This review examines attempts and breakthroughs in enhancing the physicochemical properties of carbon dioxide, focusing primarily on factors that impact solubility of polar and ionic species and attempts to enhance scCO2 viscosity.

Effect of Fluorocarbon and Hydrocarbon Chain Lengths in Hybrid Surfactants for Supercritical CO2

“…This is especially true if the elongated reversed micelles can increase CO2 viscosity, which would significantly improve the poor efficiency of EOR CO2-flooding 17 . Further W/CO2 microemulsion studies on FC6-HCn will be focused on how reversed micelle morphology changes with concentration, W0, and/or the other additives (metal ions, cosurfactants or hydrotropes) [38][39][40] and explore the use of elongated reversed micelle generation for increasing CO2 viscosity for efficient EOR technologies.…”

Economical and Efficient Hybrid Surfactant with Low Fluorine Content for the Stabilisation of Water-in-CO2 Microemulsions

“…Supercritical carbon dioxide is considered a desirable solvent for green material and chemical processing [1][2]. Over the past few decades supercritical carbon dioxide (sc-CO2) has been used for various applications [3][4] and interest still remains high today [5][6][7][8].…”

Enhanced corrosion protection performance with MWCNT dispersed epoxy coating prepared under supercritical CO2 assistance

“…The dissolving properties and fast diffusion rate of scCO 2 enable the quick incorporation of MWCNT and its homogeneous dispersion throughout the polymer. Upon depressurization, the CO 2 quickly diffuses out and gets completely removed on vacuum degassing . Prior to curing, the dispersion of 1 wt% MWCNT into epoxy resin was optimized through UV‐visible spectroscopy on the basis of Van Hove singularities .…”

“…In this report, we propose a green, facile, and efficient scCO 2 processing route to improve the MWCNT dispersion in the epoxy matrix. The advantages afforded by scCO 2 of being non‐flammable and non‐toxic have sparked interesting efforts, making it to be used as an alternative to organic solvent for dispersion of nanofiller into polymers . The scCO 2 possesses gas‐like diffusivity, liquid‐like density, low viscosity, and zero surface tension, allowing it to wet out even the complicated structures.…”