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Herein, we report a facile preparation method for mechanically robust and thermally enhanced sand‐polyacrylamide (PAM)‐2D‐nanofillers composite hydrogels and their application in water shutoff. To prepare the sample, 4 wt% of aqueous PAM solution is mixed with organic cross‐linkers of hydroquinone (HQ) and hexamethylenetetramine (HMT) in a 1:1 weight ratio and aqueous potassium chloride (KCl) solution and with a specific amount of 2D‐nanofillers such as commercial graphene (CG) nanosheets or boron nitride nanoparticles (BN NPs). A specific amount of the above solution is added to sand, well mixed, and subsequently cured at 150°C for 8 h. The prepared composite hydrogels were characterized by Fourier‐transform infrared spectroscopy (FT‐IR) for chemical composition and X‐ray diffraction (XRD) for successful hydrogel coating onto the sand particles. Thermal stabilities of the samples have been evaluated by differential scanning calorimetry (DSC). Mechanical properties (storage modulus [G′]; loss modulus [G″]; gel strength (G′/G″); and damping factor [G″/G′]) of the samples were determined using dynamic mechanical analyses. The thermal stability of the samples has reached as high as 193.4°C, while the gel strength is found to be a maximum of 16.2. The water swelling ratio for the composite hydrogel has reached a maximum of 1100% within 1 h. [ABSTRACT FROM AUTHOR]

The present study reports, high‐performance polymer absorbents for crude oil and organic solvents based on 3D cross‐linked polystyrene‐polymethyl methacrylate/divinyl benzene (PS‐PMMA/DVB). The preparation of the 3D cross‐linked polymer absorbents has been carried out by bulk polymerization method using styrene (S) and methyl methacrylate (MMA) monomers in the presence of DVB with azobisisobutyronitrile as an initiator. The prepared cross‐linked polymer absorbents were characterized by Fourier transform infrared spectroscopy, thermogravimetric and differential scanning calorimetry, and dynamic mechanical analyses. The absorption kinetics, thermodynamics of the absorption process as well as the recyclability of the cross‐linked polymer absorbents were investigated in detail. The developed 3D cross‐linked PS‐PMMA/DVB absorbents have demonstrated excellent absorption capacities for both organic solvents and crude oil. For instance, the developed polymer absorbent (PS‐PMMA/DVB [1 wt%]) shows a maximum absorption capacity of 12 g/g for chloroform, 6 g/g for tetrahydrofuran, and 3 g/g for crude oil. The absorption capacities by the polymer absorbents show a direct relationship with the polarity of the solvents. Moreover, the change of absorption capacity after several repeated cycles of absorption/desorption was only marginal. The demonstrated absorption capacities and the excellent recyclability make polymer absorbents as potential candidates for the oilfield applications and produced water treatments. [ABSTRACT FROM AUTHOR]

Two-dimensional atomically thick materials such as graphene and layered molybdenum disulfide (MoS 2 ) have been studied as potential energy storage materials because of their high specific surface area, potential redox activity, and mechanical flexibility. However, because of the layered structure restacking and poor electrical conductivity, these materials are unable to attain their full potential. Composite electrodes made of a mixture of graphene and MoS 2 have been shown to partially resolve these issues in the past, although their performance is still limited by inadequate mixing at the nanoscale. Herein, we report three composites via a simple ball-milling method and analyze supercapacitor electrodes. Compared with pristine graphene and MoS 2 , the composites showed high capacitance. The as-obtained MoS 2 @Graphene composite (1:9) possesses a high surface area and uniform dispersion of MoS 2 on the graphene sheet. The MoS 2 @Graphene (1:9) composite electrode has a high specific capacitance of 248 F g -1 at 5 A g -1 in an electrochemical supercapacitor compared with the other two composites. Simultaneously, the flexible symmetric supercapacitor device prepared demonstrated superior flexibility and a long lifespan (93% capacitance retention after 8000 cycles) with no obvious changes in performance under different angles. In portable and wearable energy storage devices, the current experimental results will result in scalable, freestanding hybrid electrodes with improved, flexible, supercapacitive performance., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Herein, we report a facile process for the preparation of styrene and methyl-methacrylate copolymer nanocomposites containing reduced graphene oxide and silver nanoparticles ((R-(GO-(PS-PMMA))/AgNPs)) by using (i) microwave irradiation (MWI) to obtain R-(GO-(PS-PMMA))/AgNPs and (ii) the in situ bulk polymerization technique to produce RGO/AgNPs-(PS-PMMA). Various characterization techniques, including FT-IR, XPS, Raman spectroscopy, XRD, SEM, HR-TEM, DSC, and TGA analysis, were used to characterize the prepared nanocomposites. The Berkovich nanoindentation method was employed to determine the hardness and elastic modulus of the nanocomposites. The results showed that the MWI-produced nanocomposites were found to have enhanced morphological, structural, and thermal properties compared with those of the nanocomposites prepared by the in situ method. In addition, the antibacterial activity of the prepared nanocomposites against the E. coli HB 101 K-12 was investigated, whereby an inhibition zone of 3 mm (RGO/AgNPs-(PS-PMMA) and 27 mm (R-(GO-(PS-PMMA))/AgNPs) was achieved. This indicates that the MWI-prepared nanocomposite has stronger antibacterial activity than the in situ-prepared nanocomposite.