FIG. 5.

Chemical reaction using sc ${\mathrm{CO}}_2$ in microfluidics. (a) Hydrogenation reaction of cyclohexene in a silicon-glass microreactor with the addition of sc ${\mathrm{CO}}_2$ as a solvent, where intensified mixing was observed upon sc ${\mathrm{CO}}_2$ injection from the microscopic images on the right.⁸⁹ Reproduced with permission from Trachsel et al., J. Supercrit. Fluids 48, 146–153 (2009). Copyright 2009 Elsevier. (b) The glass microreactor and experimental setup were designed by Benito-Lopez et al. to perform an esterification reaction of phthalic anhydride and methanol, with sc ${\mathrm{CO}}_2$ as a co-solvent that leads to rate enhancement.⁹¹ Reproduced with permission from Benito-Lopez et al., Lab Chip 7, 1345–1351 (2007). Copyright 2007 Royal Society of Chemistry.