Jiayi Lv,Chenglong Zou,Qi Dai,Yin Zhao,Mengqi Zhu,Xiyue Liu,Siqi Huan,Shuo Dou,Long Bai
Pickering emulsions stabilized by nanocelluloses have been utilized within food, cosmetic, and pharmaceutical industries owing to their prolonged stability. However, high hydrophilicity and large dimension of cellulose nanofibrils (CNF) obtained through mechanical disintegration limit their adsorption at the oil/water interface. Herein, aldehyde-modified TEMPO-oxidized CNF (ACNF) with different oxidation degrees is prepared to improve Pickering emulsion stability, broadening its application in asphalt recovery. A battery of characterization methods (TEM, turbidity, contact angle, etc.) demonstrate the installation of aldehyde groups on the ACNF and change of the properties. The aldehyde groups improve hydrophobicity of ACNF while maintaining sufficient carboxyl groups to retain electrostatic repulsion. The fiber length of ACNF decreases with increasing aldylation degree, influencing the amount of ACNF absorbed at the droplet surface. Pickering emulsion stabilized by ACNF-0.12 show optimal performances. The obtained ACNF effectively stabilizes high oil content and different oil types with long-term stability. Flowable Pickering emulsions containing asphalt are obtained. This study offers comprehensive investigation on the influence of aldehyde-modified ACNF on Pickering emulsion preparation, aiming at developing new approaches for various applications.
Solution plasma catalysis has emerged as a promising strategy for the sustainable and rapid production of hydrogen peroxide (H 2 O 2 ) from water and oxygen by clean electricity. However, the uncontrollable electron loss and inefficient utilization of reactive species in solution plasma significantly limit the plasma-to-H 2 O 2 (PTH) conversion efficiency. This lack of control over the plasma environment makes it challenging to design catalysts capable of selectively channeling reactive species toward H 2 O 2 production. Here, we develop modified C 3 N 4 with different functional groups to improve PTH conversion efficiency. The aldehyde-modified C 3 N 4 achieves an unprecedented H 2 O 2 production rate of 4.4 ± 0.1 mM h −1 and a remarkable PTH conversion efficiency of 1.3 %, which is 16 times higher than that of the plasma system without a catalyst. We clarified by density functional calculations and spectroscopic measurements that the improved H 2 O 2 yields and efficiency are due to the modification of the electron-withdrawing groups to promote the generation of 1 O 2 intermediates. This work confirms the critical importance of rational catalyst design to improve PTH conversion efficiency, paving the way for sustainable and rapid solution-based chemical synthesis.
Peritoneal adhesion is a common problem after abdominal surgery and can lead to various medical problems. In response to the lack of in situ retention and pro-wound healing properties of existing anti-adhesion barriers, this work reports an injectable adhesive-antifouling bifunctional hydrogel (AAB-hydrogel). This AAB-hydrogel can be constructed by “two-step” injection. The tissue adhesive hydrogel based on gallic acid-modified chitosan and aldehyde-modified dextran is prepared as the bottom hydrogel (B-hydrogel) by Schiff base reaction. The aldehyde-modified zwitterionic dextran/carboxymethyl chitosan-based hydrogel is formed on the B-hydrogel surface as the antifouling top hydrogel (T-hydrogel). The AAB-hydrogel exhibits good bilayer binding and asymmetric properties, including tissue adhesive, antifouling, and antimicrobial properties. To evaluate the anti-adhesion effect in vivo, the prepared hydrogels are injected onto the wound surface of a mouse abdominal wall abrasion-cecum defect model. Results suggest that the AAB-hydrogel has antioxidant capacity and can reduce the postoperative inflammatory response by modulating the macrophage phenotype. Moreover, the AAB-hydrogel could effectively inhibit the formation of postoperative adhesions by reducing protein deposition, and resisting fibroblast adhesions and bacteria attacking. Therefore, AAB-hydrogel is a promising candidate for the prevention of postoperative peritoneal adhesions.
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