Traditional microstructure scale parameters have difficulty describing the structure and distribution of a rough material’s surface morphology comprehensively and quantitatively. This study constructs hydrophilic and underwater oleophobic surfaces based on polyvinylidene fluoride (PVDF) using a chemical modification method, and the fractal dimension and multifractal spectrum are used to quantitatively characterize the microscopic morphology. A new contact angle prediction model for underwater oleophobic surfaces is established. The results show that the fractal dimension of the PVDF surface first increases and then decreases with the reaction time. The uniformity characterized by the multifractal spectrum was generally consistent with scanning electron microscope observations. The contact angle of water droplets on the PVDF surface is negatively correlated with the fractal dimension, and oil droplets in water are positively correlated. When the fractal dimension is 2.0975, the new contact angle prediction model has higher prediction accuracy. The maximum and minimum relative deviations of the contact angle between the theoretical and measured data are 18.20% and 0.72%, respectively. For water ring transportation, the larger the fractal dimension and spectral width of the material surface, the smaller the absolute value of the spectral difference, the stronger the hydrophilic and oleophobic properties, and the better the water ring transportation stability.

Anti-coking oxide films were prepared on a 25Cr35Ni and 35Cr45Ni alloy surface under the low oxygen partial pressure atmosphere of a H2-H2O mixture. The composition and phase structure of the oxide films were analyzed by energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The anti-coking performance of a mini tube made of a HP40 (25Cr35Ni) alloy was evaluated on a bench scale pyrolysis and coking test unit. The results showed that the surface Fe and Ni content decreased after the oxidation of the two alloys in a low oxygen partial pressure atmosphere. The oxide films were mainly composed of MnCr2O4 and Cr2O3. The average mass of coke in the mini tube with oxide film decreased by 87% relative to that of a tube without an oxide film when the cracking temperature was 900 °C. The ethylene, propylene, and butadiene yields in the pyrolysis tests were almost the same for the mini tubes with and without an oxide film. The oxide film on the alloy surface effectively inhibited catalytic filamentous coke formation. An industrial test showed that the run length of the cracking furnace with the in-situ coating technology was significantly extended.

A copper-based non-aqueous-phase desulfurization agent is prepared by adding CuCl2 to the solvent N,Ndimethylformamide (DMF). Static desulfurization experiments show that the agent has high efficiency. However, the desulfurization reaction leads to the formation of a copper sulfide precipitate. It is found that the addition of chloride ions in the form of hydrochloric acid or potassium chloride prevents the formation of copper sulfide, and elemental sulfur is precipitated instead. The efficient absorption of H2S by the Cu/HCl–DMF agent relies on the rapid coordination of Cu2+ with DMF, Cl−, and H2S molecules to form a [Cu(DMF)n−p(HS−)p(Cl−)m](2−p−m)+ complex. The desulfurization agent has a sulfur capacity of up to 9.81 g/L when used in static bubble desulfurization at atmospheric pressure. The system has low viscosity and good chemical and thermal stability. It can be rapidly regenerated through continuous oxidation. After five repetitions of the regeneration procedure, the sulfur capacity reaches more than 91% of the initial capacity, indicating the potential of the system for commercial applications.

Gelation adversely affects the aqueous adiabatic terpolymerization of acrylamide (AM), sodium acrylate (NaAA), and 2-methacryloyloxyethyl trimethylammonium chloride (DMC). Here, the mixed dispersants sorbitan monooleate (Span 80) and polyoxyethylene sorbitan monooleate (Tween 80) were introduced to the terpolymerization system in an attempt to mitigate the gel effect. This enabled the preparation of high-performance amphoteric polyacrylamides, which were characterized by Fourier-transform infrared spectroscopy and thermogravimetric analysis. The influences of the dispersant type and content as well as the hydrophilic-lipophilic balance (HLB) on the gel effect were examined, and the mechanism underlying the suppression of the gel effect was considered. The obtained results indicated that the gel effect can be effectively mitigated using an aqueous adiabatic terpolymerization system containing mixed Span 80/Tween 80 dispersants at various contents. In particular, mixed dispersant contents of 0.6%–0.8% with HLB values of 5.0–6.0 afforded the optimal performance (e.g., high viscosity, fast aqueous dissolution time, and the like).

Polyimide (PI) is an organic polymer material with good stability and diverse sources that has attracted widespread attention in the field of photocatalysis. In this study, a series of PI photocatalysts were synthesized by a thermal polymerization approach using pyromellitic dianhydride (PMDA) and various diamine monomers (melamine (MA), 4,4′-oxydianiline, and melem) as the precursors as well as different heating rates. The effects of the diamine precursor and heating rate on the structure, composition, morphology, and optical properties of the as-prepared PI materials were systematically investigated by various characterization techniques. The selective photo-oxidation of benzylamine was used as a model reaction to evaluate the photocatalytic activities of the resulting PI samples for the oxidation of amines to imines. The results revealed that the PI sample prepared using MA and PMDA as the precursors and a heating rate of 7 °C/min (MA-PI-7) exhibited the best catalytic performance, with 98% benzylamine conversion and 98% selectivity for N-benzylidene benzylamine after 4 h of irradiation. Several benzylamine derivatives and heterocyclic amines also underwent the photo-oxidation reaction over the MA-PI-7 catalyst to afford the corresponding imines with good activity. In addition, MA-PI-7 exhibited good stability over four successive photocatalytic cycles.

The size of the nanoparticles and the number of oxygen vacancies have a significant effect on the catalytic activity of copper-based catalysts used for the synthesis of methanol from syngas. In this study, the authors prepared a series of catalysts CuO/ZnO/Al2O3/CeO2 (CZAC) with CuO particles of different sizes and varying number of oxygen vacancies on the surface by changing the added volume of CeO2 by using the co-precipitation method. The properties of the catalysts were characterized and their activity was evaluated by using high-pressure fixed-bed reaction equipment. The results showed that the addition of CeO2 to CuO/ZnO/Al2O3 not only influenced the size of the CuO particles and metal-metal interactions, but also had an effect on the concentrations of oxygen vacancies and strongly basic sites. The presence of CuO particles of small sizes and a large numbers of oxygen vacancies on the surface of the catalyst were beneficial to its activity for the synthesis of methanol. The catalyst CZAC, when modified by 5% of CeO2, recorded CuO particles of the smallest size (8.9 nm), strong intermetallic interactions, and the highest concentrations of oxygen vacancies and strongly basic sites. It also exhibited the highest catalytic activity, with a space-time yield of methanol of 0.315 g/(h·g) that was higher than that of the enterprise RK-5 catalyst [0.215 g/(h·g)].

A C9H10O2:0.5ZnCl2/SG catalyst was synthesized using a one-step sol-gel method with silica gel (SG) as the carrier and C9H10O2:0.5ZnCl2 deep eutectic solvent (DES) as active component. The structure of the supported catalyst was characterized by FT-IR, XRD, SEM, and N2 adsorption-desorption, and the DES was found to have successfully permeated the SG through its pores. The removal of dibenzothiophene (DBT) in model diesel was studied using C9H10O2:0.5ZnCl2/SG as a catalyst and H2O2 as an oxidant. The influence of loading dose of DES, reaction temperature, catalyst dosage, O/S molar ratio, and sulfide type on the desulfurization rate was investigated. The removal rates of DBT, 4,6-dimethyldibenzothiophene (4, 6-DMDBT), and benzothiophene (BT) under optimal reaction conditions were 99.4%, 96%, and 78.2%, respectively. C9H10O2:0.5ZnCl2/SG catalyst could be recycled five times with a little decrease of oxidative desulfurization activity, and the adsorption-oxidation desulfurization mechanism was examined.