Bicontinuous Interfacially Jammed Emulsion Gels (bijels) as Media for Enabling Enzymatic Reactive Separation of a Highly Water Insoluble Substrate

Abstract

Although enzymes are efficient catalysts capable of converting various substrates into desired products with high specificity under mild conditions, their effectiveness as catalysts is substantially reduced when substrates are poorly water-soluble. In this study, to expedite the enzymatic conversion of a hydrophobic substrate, we use a bicontinuous interfacially jammed emulsion gel (bijel) which provides large interfacial area between two immiscible liquids: oil and water. Using lipase-catalyzed hydrolysis of tributyrin as a model reaction in a batch mode, we show that bijels can be used as media to enable enzymatic reaction. The bijel system gives a four-fold increase in the initial reaction rate in comparison to a stirred biphasic medium. Our results demonstrate that bijels are powerful biphasic reaction media to accelerate enzymatic reactions with various hydrophobic reagents. This work also demonstrates that bijels can potentially be used as reaction media to enable continuous reactive separations.

Controlling Surfactant Adsorption on Highly Charged Nanoparticles to Stabilize Bijels

“…Bicontinuous interfacially jammed emulsion gels (bijels) have found numerous uses as batteries, − filters, tissue engineering scaffolds, ultralight materials, , and catalytic microreactors. , Bijels consist of two continuous liquid phases arranged within an intertwined channel network. This out-of-equilibrium structure is stabilized by a rigid film of colloidal particles at the liquid–liquid interface. , Bijels can be generated either via spinodal phase separation ,, or vigorous agitation of two immiscible fluids. , In both cases, colloidal particles stabilize the liquid network via interfacial jamming due to the enormous particle attachment energies equaling thousands of kT…”

Multicompartment Hydrogels

“…[157] Lee and co-workers described a bijel as environment for enzymatic catalysis. [158] The bijel was formed from water and diethylphthalate and stabilized by silica nanoparticles as well as cetyl ammonium bromide via the solvent transferinduced phase separation process [157] to form fiber bijels. In particular, bijel was employed to improve the conversion of hydrophobic substrates due to increased interfacial area between hydrophobic and hydrophilic phase.…”

Rapid production of bicontinuous macroporous materials using intrinsically polymerizable bijels

“…6,7 Since their discovery, bijels have attracted considerable attention as templates for advanced materials synthesis, with applications ranging from cell delivery 8 and regenerative biomaterials 9 to electrochemical energy storage [10][11][12] and catalysis. 13 The main driver for this rapid surge in interest is twofold. First, inherent to the mechanism by which they are formed, bijels have a unique microstructure with desirable attributes at length scales relevant to the applications mentioned above.…”