Pickering Emulsions Stabilized by Lignin/Chitosan Nanoparticles for Biphasic Enzyme Catalysis

Abstract

In this study, we construct a green and highperformance platform using Pickering emulsions for biphasic catalysis. The oil-in-water Pickering emulsions stabilized by the lignin/chitosan nanoparticles (Lig/Chi NPs) have great stability and alkali resistance, showing pH-responsive reversible emulsification and demulsification which can be recycled at least three times. The Pickering emulsion also has fluorescence and wide availability to different oil-to-water volume ratios, types of oil, storage times, temperatures, and ion concentrations. When this system is applied to the lipase-catalyzed reaction for the hydrolysis of p-nitrophenol palmitate, it will provide stable and large oil-water reaction interface areas, and the negatively charged lipase will enrich at the emulsion interface by electrostatic adsorption of the positively charged Lig/Chi NPs to achieve immobilization (lipase-Lig/Chi NPs). The reaction conversion rate can reach nearly 100% in 30 min, which is nearly three times higher than that of the conventional two-phase system. Moreover, the lipases in Pickering emulsion stabilized by Lig/Chi NPs exhibit great recyclability because of the protection of Lig/Chi NPs.

Facile design of renewable lignin copolymers by photoinitiated RAFT polymerization as Pickering emulsion stabilizers

“…Upon visual comparison of the freshly prepared emulsions, the systems formed using high-boiling-point heavy aromatic solvent S200 were superior to those obtained by mixing fatty acid methyl ester (FAME) and ethylene glycol diacetate (EGDA) since the proportion of the emulsion layer gradually increased. 68 This effect is closely related to the difference in hydrophobic interactions between different oil phases and water molecules. 67 The emulsion stability was assessed over 60 days through visual inspection (Fig.…”

CO2 Switchable Pickering Emulsion Stabilized by Responsive Janus SiO2 Nanoparticles for Enhanced Oil Recovery

“…It is anticipated that the emulsion will have controllable stability . For these purposes, stimuli-responsive and switchable Pickering emulsions have been demonstrated advantages due to their ability to undergo emulsification and demulsification in a controlled manner, triggered by various stimuli such as pH, magnetic fields, light, temperature, CO 2 /N 2 , etc. − …”

“…With the development of Pickering emulsions in industrial and scientific applications, it is believed that emulsion stability is a temporary necessity limited to certain domains of emulsion systems such as biphasic catalysis and oil transportation. It is anticipated that the emulsion will have controllable stability . For these purposes, stimuli-responsive and switchable Pickering emulsions have been demonstrated advantages due to their ability to undergo emulsification and demulsification in a controlled manner, triggered by various stimuli such as pH, magnetic fields, light, temperature, CO 2 /N 2 , etc. − …”

Fabrication of Poly(ε-caprolactone)-embedded Lignin-Chitosan Nanocomposite Porous Scaffolds from Pickering Emulsions

“…It is necessary to develop new avenues for the high-value utilization of lignin in the preparation of sustainable materials, which have promising potential to resolve the problem of the fast depletion of fossil resources. Lignin possesses typical favorable characteristics of biocompatibility, antimicrobial activity, renewability, adsorption performance, antioxidant property, and abundance. − All these propel lignin as an interesting building block of scaffold biomaterials for biomedical applications. In view of its poor solubility and fragile nature, a strategy to improve the use of lignin in preparing porous scaffolds is to create a composite by combining lignin nanoparticles with other biopolymers.…”