Pore-scale numerical investigations were conducted to elucidate the mechanisms underlying the enhanced oil recovery performance of miscible CO2 flooding in low-permeability porous media. By integrating mercury intrusion porosimetry with micro-computed tomography (micro-CT) imaging, digital rock models with realistic pore geometries were reconstructed. Two characteristic pore size scales, 1 mu m and 0.1 mu m, were considered to capture the multiscale geometry of the core. The pore-scale displacement behaviors of immiscible N2 and miscible CO2 flooding were comparatively investigated using computational fluid dynamics (CFD) simulations that account for the coupled effects of pore size and interfacial tension (IFT). The results show that as IFT diminishes, miscible CO2 flooding effectively displaces oil from both large and small pores. In contrast, immiscible N2 flooding mobilizes oil only from larger pores, leaving most of the oil trapped in smaller pores due to capillary effects. The simulation results for both immiscible N2 and miscible CO2 flooding exhibit good agreement with experimental data. These findings help bridge the gap between pore-scale numerical simulations and macroscale laboratory studies and provide valuable insights into the effectiveness of miscible CO2 flooding for enhanced oil recovery.

Achieving seamless tiling through the self-assembly of organic species has long fascinated scientists for its potential applications across various fields. However, constructing periodic nanostructures with high-order tessellation remains challenging, particularly in achieving precise control at the supramolecular level. In this study, we present the successful creation of multiple seamless 2D tessellations on Au(111) surface using versatile hexagonal tiles derived from a singular molecular unit, namely 2,6,10-tribromotricycloquinazoline. Through scanning tunneling microscopy imaging, seven distinct 2D tessellations, ranging from regular to semiregular to k-uniform tilings, are unveiled at the molecular level. Density functional theory calculations provide a theoretical basis for the formation of these complex 2D tessellation, highlighting the important role of the variability of Br···Br/H contacts in facilitating complex seamless 2D tessellations on surface. This work opens avenues for exploring possibilities in constructing intricate tiling patterns with diverse applications.

The flocculating ability of the flocculant directly affects the quality of the treated water. Poly-ferric sulfate flocculant (PFS) is a commonly used flocculant. The purpose of this study is to use the electrodialysis process to concentrate the solution and the bipolar membrane electrodialysis to dissociate water to produce acid and alkali to achieve the preparation of poly-ferric sulfate flocculant. The effects of current density, feed flow rate, and sulfuric acid addition on the quality of PFS were tested. Experiments have proved that the increase of current density is beneficial to the increase of PFS alkalinity and turbidity removal rate, and at the same time energy consumption will be reduced. When the current density is 30 mA/cm2, the alkalinity reaches a maximum of 21.04% and the energy consumption is 1.52 kW & BULL;h (kg H2SO4). When the current density is 20 mA/ cm2, the turbidity removal rate reaches a maximum of 94.23% and the energy consumption is 2.46 kW & BULL;h (kg H2SO4). In addition, the solid PFS was subjected to scanning electron microscopy, X-ray diffraction and Fourier-transform infrared spectroscopy tests after vacuum drying to further confirm the structure of the PFS.

Chemicals electrochemical refining coupled with cathode hydrogen production could effectively reduce the overpotential and energy cost. The electrooxidation cleavage of 1,4-glycosidic bond is the urgent problems for high-value D-glucaric acid (GRA) directly from the long-chain biomass saccharide composed of glucose. Hence, we investigated the oxidation path of the maltose over the alpha-Ni(OH)(2) as model electrocatalyst. The results showed that the cleavage potential of maltose 1,4-glycosidic bond is a little higher than that of the aldehyde/ hydroxyl groups in glucose, but much lower than that of water. Compared with water oxidation, the aldehyde/ hydroxyl groups oxidation could consume the Ni(OH)O intermediate so fast that it cannot accumulate. Operando electrochemical impedance spectroscopy (EIS) showed that the 1,4-glycosidic bond cleavage is not same to the aldehyde/hydroxyl groups oxidation reactions spontaneously, which occurs directly at an initial potential. The morphology of alpha-Ni(OH)(2) would be collapsed and high-priced nickel and metal-oxygen bond would be formed during water oxidation reaction, but which unchanged for glucose and maltose oxidation. In addition, the starch was also used as the long-chain saccharide to study the 1,4-glycosidic bond cleavage and the whole reaction path. This work promotes the development of green electrocatalytic systems to achieve sustainable valorization of biomass saccharide utilization pathways.

Using styrene as a proxy for VOCs, a new method was developed to remove styrene gas in nitrogen atmospheres. The effect on the styrene removal efficiency was explored by varying parameters within the continuum dynamic experimental setup, such as ferrous ion concentration, hydrogen peroxide concentration, and pH values. The by-products are quantized by a TOC analyzer. The optimal process conditions were hydrogen peroxide at 20 mmol/L, ferrous ions at 0.3 mmol/L and pH 3, resulting in an average styrene removal efficiency of 96.23%. In addition, in this study, we construct a BAS-BP neural network model with experimental data as a sample training set, which boosts the goodness-of-fit of the BP neural network and is able to tentatively predict styrene gas residuals for different front-end conditions.

Accurate prediction of the flow characteristics in low-permeable porous media is of great importance for achieving efficient geo-energy development as well as gas geological storage practices. Due to the microscale and complex geometry of the formation structures, mechanistic studies on the flow behavior in low-permeable porous media have arisen as a challenging research topic. In this paper, a pore-scale numerical study is carried out concerning the seepage characteristics in the low-permeable Berea core. After extracting the complex pore structure from the high resolution CT images, a novel methodology is proposed to screen the simulation representative elementary volume (REV), on which the fluid flow characteristics in the low-permeable pore media are scrutinized with help of the comprehensive Computational Fluid Dynamics (CFD) software. The roughness effect, which becomes significant in microscale pore channels, is taken into account for the permeability result corrections. Based on good agreement between the pore-scale simulation and the macroscale measurement results, the capability of the proposed CFD workflow on the study of the seepage characteristics in low-permeable porous media is well demonstrated.

A Bipolar membrane electrodialysis (BMED) was performed to achieve efficient production of N, N-dimethylglycine (DMG) from dimethylglycine hydrochloride. And the two-compartment cell configuration (BP-A) was used to avoid the amino acid macromolecules migrating through the membrane resulting in membrane fouling. Several experiment parameters including current density, initial dimethylglycine hydrochloride concentration and flow rate were discussed and compared. The results indicated that the optimal operation condition was at the current density of 50 A/m(2), feed mole concentration of 0.3M and flow rate of 15L/h. Under the optimal condition, the energy consumption was 0.45 kWh/kg, the current efficiency was 65% and the recovery ratio for DMG reached 98% by calculation. In addition, the membrane fouling after experiments was conducted and further analyzed. It was observed that there was no appreciable change on the membrane during the BMED process by the SEM images and FTIR spectra. These results show that the harm of BMED process to membranes could be ignored. BMED method has the advantages of high purity, no by-products, low energy consumption and environmental friendliness. And this study can broaden the application of electrodialysis in the purification and preparation of macromolecular amino acids.

Polyvinyl alcohol/starch based composite membranes containing herbicide-loaded metal-organic-framework (MOF-5) was successfully synthesized by electrostatic spraying technique. Several main parameters affecting the adsorption of MOF-5 were studied, including the initial concentration of the herbicide solution, adsorption time, and temperature. Under optimal conditions, herbicide-loaded MOF-5 was successfully synthesized and the main properties were characterized by Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectrometer (FTIR), Thermogravimetric Analysis (TG), and Brunauer-Emmett-Teller (BET), respectively. The results showed that the adsorption capacity of MOF-5 at optimal conditions was 60.12wt%+/- 0.61 % for atrazine. The sustained release effect of the AT@MOF-5/PVA/ST composite membranes was reliable, and the cumulative release rate was about 50 % for 15 h. The release behaviour of AT from AT@MOF-5/PVA/ST composite membranes was first dominated by the mechanism of Fickian diffusion and then by the mechanism of matrix erosion. The main advantages of agricultural herbicide film can be attributed to the eco-friendly, biodegradable, and persistence of herbicide.

Facile reverse osmosis membranes with different doping concentrations of metal organic framework MIL-101(Cr)@graphene oxide (GO) were synthesized for desalination by interfacial polymerization, and the MIL-101(Cr) polyhedral particles were encapsulated with GO nanosheets. Contact angles of thin film nanocomposite membranes decrease with the increased concentration of MIL-101(Cr)@GO, suggesting improved surface hydrophilicity. And desirable doping can enhance both water flux and NaCl rejection. For example, with a doping concentration of 0.01%, water flux of the membranes can be increased from 20.49 L/m(2) .h. to 37.95 L/m(2) .h. by 85.21% along with slightly improved NaCl rejection. Our findings indicate that MIL-101(Cr)@GO composite particles can be developed as an effective additive material to fabricate thin film nanocomposite reverse osmosis membranes for desalination applications.