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Oily wastewater discharged from the petrochemical industry and people's daily life has caused severe eco-environmental issues. Thus, developing efficient and durable oil/water separation adsorbent materials is urgently desired. In this study, a durable superhydrophobic/superlipophilic polyurethane sponge with "scalelike" pore structures was synthesized by interfacial assembly via in situ anchoring of SiO2 and H-CNTs accompanied by the bonding effect and active sites from polydopamine (PDA). After modification with 1H,1H,2H,2H-perfluorooctyltriethoxysilane (POTS), the prepared sponge demonstrated a high water contact angle (WCA) up to 156.0 ± 1.4°, which could selectively absorb diverse oils ranging from 32.0 ± 0.3 to 116.0 ± 0.3 times its own weight. Meanwhile, the prepared sponge displayed superior separation efficiency up to 99.99% toward various oily emulsions due to its superhydrophobic/superoleophilic properties accompanied by the needle demulsification and diversion of H-CNTs. Notably, the prepared sponge also exhibited prominent environment tolerance against a variety of difficult harsh circumstances such as high temperature, UV irradiation and acid/alkaline solution, and the WCAs were stably over 150 ± 1.5°. Moreover, the prepared sponge possessed excellent antifouling and self-cleaning properties. Therefore, this novel durable superhydrophobic polyurethane sponge with a "scalelike" pore structure is of great significance to enable potential applications in dealing with practically challenging emulsified wastewater. [ABSTRACT FROM AUTHOR]

The purification of isomer monomers with high purity is extremely important, particularly in the fine chemical industry, pharmaceutical industry, and so on. Herein, a selective cocrystallization (SCoC) technology based on non-covalent interactions between the target compound and cocrystal conformers was developed to effectively separate isomer mixtures. The unique and efficient selectivity nature of conformers and the general applicability of the selective cocrystallization method was tested through separating and purifying cresol isomer mixtures, pyridinecarboxamide isomer mixtures, and cis−/trans-butenedioic acid mixtures. Moreover, the nature of selective recognition to cocrystallize was confirmed both in the solution and solid states. Thus, this study demonstrates the feasibility of this novel SCoC technology, which is a new method for separating isomer mixtures. [ABSTRACT FROM AUTHOR]

To investigate the effect of positional isomerism on cocrystallization and reveal the role of weak interactions in the formation of cocrystals, experimental characterization complemented with theoretical computations was thoroughly conducted by using p-hydroxybenzoic acid (PHBA), o-hydroxybenzoic acid (OHBA), m-hydroxybenzoic acid (MHBA) and malonic acid (MA) as model compounds. Selective formation of a new cocrystal was discovered between PHBA and MA molecules via several methods, while no cocrystal was formed between OHBA/MHBA and MA molecules. The PHBA–MA cocrystal was thoroughly characterized and analyzed through several solid characterization techniques such as powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC) analysis, Fourier transform infrared (FTIR) spectroscopy, single crystal X-ray diffraction (SCXRD), etc. Taking advantage of a myriad of computational modelling techniques, the molecular recognition mechanism which drove the formation of cocrystals was comprehensively investigated and understood at a molecular level. The structural change accompanied by the cocrystal formation could be rationalized by FTIR spectroscopy and electron density variation analysis. Hirshfeld surface (HS) analysis indicated that O–H⋯O hydrogen bonds played a critical role in the formation of this cocrystal. Molecular electrostatic potential (MESP) surface analysis was employed to predict the interaction sites for cocrystallization, which were in good accordance with the experimental results. Moreover, possible reasons for the selective cocrystallization were analyzed and proposed. [ABSTRACT FROM AUTHOR]

To gain further insights into the formation of cocrystals, the thermodynamic mechanism and molecular recognition process of cocrystal formation were investigated by using p-hydroxybenzoic (PHBA) as the model compound. One new 1 : 1 (molar ratio) cocrystal of p-hydroxybenzoic (PHBA) and glutaric acid (GA) was successfully synthesized via several methods, including liquid-assisted grinding, cooling crystallization, and slurry conversion crystallization. The prepared cocrystal powder was characterized by PXRD, DSC and Raman spectroscopy. The crystal structure of the cocrystal was determined and interpreted by single-crystal XRD. The ternary phase diagrams of the newly prepared cocrystal were constructed in acetonitrile at three temperatures, i.e., 2, 20 and 40 °C. The temperature was shown to have an impact on the shape of the ternary phase diagrams. Guided by the determined ternary phase diagrams, the pure PHBA–GA cocrystal could be prepared successfully by isothermal slurry conversion crystallization. Raman spectroscopy was employed to monitor the molecular recognition and self-assembly process of the conversion in situ. In addition, density functional theory calculations were conducted to determine the stability and interaction energy of the cocrystal, rationalizing the formation potential of the PHBA–GA cocrystal. [ABSTRACT FROM AUTHOR]