Enclosed films, also called capsules, bearing an ultrathin and robust nanoshell have sparked much interest for use in many applications, for which facile preparation methods are urgently pursued. Inspired by the pH-programmed adhesion/cohesion of mussel-secreted foot proteins, polyphenol/polyamine capsules with an ultrathin and robust nanoshell are fabricated through a pH-switched assembly on sacrificial calcium carbonate (CaCO3) templates. Polyphenols adhere to the templates at pH 6.0 and rapidly cohere with polyamines at pH 8.0. The pH-switched assembly process is accomplished in only a few minutes where multiple instances of electrostatic interactions and chemical conjugation between polyphenols and polyamines occur. As a result, the capsules exhibit a nanoshell thickness of ∼10 nm and a superior mechanical strength of ∼1.575 GPa (elasticity modulus). Cell mimics are prepared through encasing enzymes in the lumen and present an activity recovery of ∼70% along with little activity decline during reuse. Amine or phenolic groups on the nanoshell of capsules are then applied to induce the generation of titania or silver nanoparticles, which may expand the applications of the capsules to the photo- and biorelated realms. Our study not only deepens the understanding of the adhering process of mussels but also offers a generic method toward functional materials for diverse applications.
Ning Gao,Yunbo Wang,Huixin Luo,Yingtong Xu,Jining Liu,Yingwen Chen
The accumulation of oily waste increases annually with the growth in crude oil demand. Its toxicity and high heating value present both opportunities and challenges for treatment technologies. In recent years, the emergence of hydrophobic deep eutectic solvents (HDES) has promoted advancements in low-toxicity extraction processes. Leveraging the advantages of HDES and addressing the challenges posed by real oily sawdust (with a 67.9 % oil content), this study presents a novel green HDES solvent composed of ethyl maltol and fatty acids, accompanied by a corresponding extraction process. At a low temperature of 60 °C, the process achieved impressive results: an oil extraction efficiency close to 86.3 %, a dehydration rate exceeding 92.2 %, and a heavy metal removal rate ranging from 15 % to 75 %. In the exploration of solvents recycling, pH-switching facilitated the deprotonation and protonation of phenol-fatty acid HDES, promoting effective recovery of the oil phase. Even after 5 cycles, the oil extraction rate could still be maintained above 75 %. It is worth noting that the regenerated HDES exhibited greater selectivity for extracting light oil after multiple uses. The total ratio of saturated and aromatic hydrocarbons reached approximately 81.7 %, significantly enhancing the value of the recovered oil. Integrating systematic characterization with the extraction performance, as well as the variation in recovered oil phase components, highlighted the multifaceted effects of introducing ethyl maltol. Specifically, this effect is demonstrated in its ability to enhance the oil phase’s solubility by regulating the intermolecular spacing of HDES, and to impede the dissolution of heavy oil into its gaps by optimizing the local zone through the formation of complexes with HDES and heavy metals.
危险品化学品经营许可证（带存储）