Fig. 5
From: Ultra-thin enzymatic liquid membrane for CO2 separation and capture
Hydrophilicity depth characterization of the enzymatic liquid membrane. a Representation of the opposing hydrophilic/phobic character of the membrane surfaces and corresponding water contact angle characterization. b Control experiments designed to probe the hydrophilicity depth of the ‘amphiphilic’ membrane. The hydrophilic surface modified membrane (top row) showed a limited (18-nm-deep) atomic layer deposition (ALD) of titanium oxide (TiO2), mapping the depth of silanol groups (scale bar: 50 nm). In contrast, the fully hydrophilic membrane (bottom row) shows TiO2 deposition throughout its thickness. The effective membrane thickness of the enzymatic water-membrane for CO2 capture and separation is thus determined to be ~18 nm
