Shuai Wang,Dongfang Liu,Jihe Zhao,Xiaojiang Li,Daixue Xu,Yuan Gu,Hongsheng Lu
In this paper, a practical and environmental friendly method was successfully developed by using CO 2 -Triggered switchable water additive to reversibly emulsify and demulsify diesel, aims to provide guidance for recovering oil substances in waste oil-based drill cuttings. In this new method, N, N, N', N'-tetramethyl-1, 6-hexanediamine(TMHDA) was a switchable water additive whose aqueous solution can switch the ionic strength by addition and removal CO 2 . Then it can be used to separate diesel through reversibly emulsification and demulsification. The nuclear magnetic resonance hydrogen spectrum ( 1 H NMR) and conductivity demonstrated TMHDA have better switching performance. Then, diesel/naphthenic acid mixtures have been used for modeling the application of recovering oil substances in waste oil-based drill cuttings. When the acid value≥1.76mgKOH/g (the oil and TMHDA solution were 5 mL), diesel can be emulsified. The material produced by TMHDA and naphthenic acid have a strong surface activity so that the oil/water interfacial tension was less than 0.1 mN·m −1 . The demulsification performance was illustrated by change of the ionic strength, pH and the content of oil in the aqueous phase during the breaking process. Brief provided two optimization strategies of recycling of TMHDA additive. Finally, the possible mechanism of the new method was discussed.
Nanoemulsions are prevalent in diverse fields, such as cosmetics, food, pharmaceuticals, oil recovery, drug delivery, and templated materials synthesis, due to their high kinetic stability and versatility in structures and compositions. However, nanoemulsions remain thermodynamically unstable and gradually undergo irreversible breakdown, posing significant constraints on their applicability. Inspired by the dynamic equilibrium of atmospheric clouds, we present thermo-induced reversible nanoemulsification of biphasic liquid systems through cyclic heating and cooling processes. With our strategy, nanodroplets dissipate through dissolution upon heating and re-emerge through nucleation upon cooling, driven by temperature-dependent solubility. Combining experimental, numerical, and theoretical studies, we identify the critical conditions for nanoemulsification, elucidate the physicochemical mechanism of nucleation, and predict the size of nanodroplets. Thermo-induced nanoemulsification (TINE) offers a reversible, facile, and scalable method for energy-efficient, surfactant-free production of nanoemulsions, characterized by good emulsion stability, diverse emulsion types, and precise control over droplet size.
In this work, pH-responsible Pickering emulsion stabilized by polymer-metal hybrid micelles and its catalytic application for reaction at oil–water interface were presented. Employing Au@poly(ethylene oxide)-b-poly(4-vinylpyridine) polymer-metal hybrid micelles as emulsifier, n -decanol in water Pickering emulsion was first generated. The produced Pickering emulsion displayed reversible emulsification/demulsification with pH variation of the water phase, and this pH-induced emulsification/demulsification could undergo multiple cycles with only a slight reduction in emulsion performance. Dynamic light scattering, zeta potential measurement, and interfacial tension measurement, as well as transmission electron microscopy characterization, all showed that this reversible emulsification/demulsification cycle was the result of the tunable wettabilities of the core cross-linked hybrid emulsifier micelles with pH variation. Benefited from the excellent catalytic performances of the implanted Au nanoparticles at the oil–water interface and the large interfacial area of the emulsion droplets together with the pH-responsible reversible emulsification/demulsification cycle, the generated Pickering emulsion could readily applied as a catalytic microreactor for a broad of organic reactions occurred in water medium. As a proof of the concept, Au catalyzed reduction reaction of p -nitroanisole by NaBH 4 was investigated. The catalyst showed both a highly catalytic activity with a good recyclability.
危险品化学品经营许可证（带存储）