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To promote the application of lignin in Pickering emulsions, the influences of six lignin particles with different hydrophobicity on the emulsifying and stabilizing performances for oil phases with different polarity to form oil in water Pickering emulsions were investigated. The results showed that the best emulsification performance was achieved when the three-phase (oil–water–lignin particle) contact angle was close to 90°. Alkyl-bridged lignin particles with stronger hydrophobicity have a better emulsification effect on cyclohexane with less polarity, while carboxymethylated lignin particles with stronger hydrophilicity have better emulsification effect on n-heptanol with higher polarity. Furthermore, the stability of Pickering emulsions can be improved by appropriately increasing the surface charge and decreasing the particular size of the lignin particles. [ABSTRACT FROM AUTHOR]

Lignin exhibits a long‐active UV‐blocking property due to its macromolecular aromatic structure and unique semiquione‐quione‐hydroquione transition. However, its poor absorbance in UVA region (320–400 nm) and irregular aggregation are still the obstacles. Herein, active spirapyrane (SP‐Br) is synthesized and covalently introduced into alkali lignin (AL) to construct photo‐stimulated UV‐absorbing enhancement sunscreen actives (AL‐SPn). The introduction of SP significantly improved the absorbance of AL in UVA region and its aggregation is effectively eased. When the optimal AL‐SP3 solution is exposed to UV irradiation, the color turned purple, and the absorbance in UVA region further improved as the unconjugated SP transformed into conjugated merocyanine (MC) structure. When the light is removed, the solution recovered light yellow. The antioxidant property of AL endow the reversible SP‐MC transformation with good cyclic stability. As‐prepared AL‐SP3 based sunscreen exhibit obvious photo‐stimulated enhancement effect. The sun protection factor (SPF) improved from 23 to 89 after 4 h irradiation, and can maintain the high performance for another 8 h. In addition, it exhibit low permeation and good biocompatibily in vitro and vivo, demonstrating its good potential in practical use. [ABSTRACT FROM AUTHOR]

Recently, metal–organic frameworks (MOFs) have become a promising carrier for immobilized enzymes. However, the long transmission distance and microporous nature of traditional 3D ZIF-8 materials not only reduce the accessibility of the enzyme and the substrate, but also the enzymes "encapsulated" by microporous ZIF-8 suffer compromising enzyme activity (<10% of the original enzyme activity). In this article, a method is proposed to construct one kind of new-type mesoporous 3D ZIF-8-Cu composed of 2D nanostructures that utilize a metal competitive coordination-induced defect structure by adjusting a metal guide agent copper chloride (CuCl). In addition, the feasibility of in situ encapsulating β-G within the developed mesoporous 3D ZIF-8-Cu endows that the enzyme complex (β-G@ZIF-8-Cu) possessed remarkably enhanced synergistic catalysis ability. The enzyme activity of mesoporous β-G@ZIF-8-Cu (with respect to cellobiose) was up to 50.1%, while that of 3D microporous β-G@ZIF-8 was only 5.1% at 50 °C. Significantly, with the increase of temperature, the enzyme activity of mesoporous β-G@ZIF-8-Cu increased as high as approximately 178.3%, almost 34.2 times that of β-G@ZIF-8 (5.2%) at 90 °C. This improvement results from the expansion of pores (significantly increased at 10∼50 nm), promoting substrate diffusion, and the thinner 2D structure shortened the mass transfer distance, accelerating the transport rate of reactants. In addition, 3D mesoporous β-G@ZIF-8-Cu composed of multilayer 2D nanostructures with better high-temperature resistance. [ABSTRACT FROM AUTHOR]