Surface Engineering of Polypropylene Membranes with Carbonic Anhydrase-Loaded Mesoporous Silica Nanoparticles for Improved Carbon Dioxide Hydration

Abstract

Carbonic anhydrase (CA) is a native enzyme that facilitates the hydration of carbon dioxide into bicarbonate ions. This study reports the fabrication of thin films of active CA enzyme onto a porous membrane substrate using layer-by-layer (LbL) assembly. Deposition of multilayer films consisting of polyelectrolytes and CA was monitored by quartz crystal microgravimetry, while the enzymatic activity was assayed according to the rates of p-nitrophenylacetate (p-NPA) hydrolysis and CO2 hydration. The fabrication of the films onto a nonporous glass substrate showed CO2 hydration rates of 0.52 ± 0.09 μmol cm(-2) min(-1) per layer of bovine CA and 2.6 ± 0.7 μmol cm(-2) min(-1) per layer of a thermostable microbial CA. The fabrication of a multilayer film containing the microbial CA on a porous polypropylene membrane increased the hydration rate to 5.3 ± 0.8 μmol cm(-2) min(-1) per layer of microbial CA. The addition of mesoporous silica nanoparticles as a film layer prior to enzyme adsorption was found to increase the activity on the polypropylene membranes even further to a rate of 19 ± 4 μmol cm(-2) min(-1) per layer of microbial CA. The LbL treatment of these membranes increased the mass transfer resistance of the membrane but decreased the likelihood of membrane pore wetting. These results have potential application in the absorption of carbon dioxide from combustion flue gases into aqueous solvents using gas-liquid membrane contactors.

In situ layer-by-layer assembled carbonic anhydrase-coated hollow fiber membrane contactor for rapid CO2 absorption

“…Our previous work has shown that the fabrication of CA-containing polyelectrolyte films via LbL assembly on a flat sheet polypropylene membrane was useful in increasing the rate of CO 2 hydration into HCO and reducing pore wetting [21]. We found that enzyme immobilization did not affect the CA activity under these conditions.…”

“…In our previous work, we showed that it was possible to obtain uniform coverage of a flat sheet PP membrane with a PEI/PSS/PAH/[PSS/PAH/NCA] 3 coating applied using a simple paintbrush [21]. In this work, SEM images of the PDMS membrane before and after adsorption (Figures 1a and 1b) indicate that the surface of the PDMS layer is evenly coated with the polyelectrolyte solution, probably because it was already smooth and non-porous prior to adsorption.…”

“…The immobilization of proteins onto flat sheet microporous membranes via LbL technology has been investigated previously [17,20,21]. However, these membranes have been used mainly for catalyzing reactions that occurred within a singular liquid phase, not in a biphasic gas-liquid absorption system.…”

Plasmonic Retrofitting of Membrane Materials: Shifting from Self‐Regulation to On‐Command Control of Fluid Flow

“…[28] An additional value of this structural configuration stems from the nature of the silica coating delimiting the inner plasmonic chamber (Figure 1g). [30][31][32][33] Once the plasmonic nanocapsules (AuNCs) were synthesized, a homogeneous layer of poly(N-isopropylacrylamide) (PNIPAAm) www.advmat.de www.advancedsciencenews.com was grafted onto their outer surface (Figure 1e,f,m,n). [29] Further applications of mesoporous silica nanoparticles in membrane technology have been recently reported in the literature.…”

Widening CO2-facilitated transport passageways in SPEEK matrix using polymer brushes functionalized double-shelled organic submicrocapsules for efficient gas separation

“…CO 2 is more dissolved in water than that of CH 4 and N 2, resulting in a higher separation performance. Moreover, water can swell polymer chain and enhances the polymer chain mobility, thus decreasing gas diffusion resistance [35][36][37][38][39][40][41][42]. The water vapor in flue gas humidifies the FSC membrane, hence facilitating gas transport.…”