Increasing electromagnetic pollution calls for electromagnetic interference (EMI) shielding materials, especially sustainable, lightweight, and environmentally stable, biomass-based materials. MXene-coated wood (M/wood) is prepared by simply spraying MXene sheets on the wood surface. Varying this spray coating manipulates the shielding performance and its application to different wood species. The M/wood exhibits high electrical conductivity (sheet resistance is only 0.65 Ω/sq) with an excellent EMI shielding effectiveness of 31.1 dB at 8.2?~?12.4 GHz and is also fire retardant. Furthermore, waterborne acrylic resin (WA) is coated on M/wood to enhance environmental stability. The WA coating improves EMI shielding performance stability after water-soaking and drying testing and prevents the peeling of MXene from wood. These satisfactory properties of WA-M/wood and the facile manufacturing approach promote the feasibility of wood-based EMI shielding materials.
Graphical abstractA simple, efficient and green approach to the synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones has been developed via one-pot three-component reaction of aromatic aldehyde, malononitrile and phthalhydrazide catalyzed by zinc–proline complex (Zn[L-proline]2) using H2O: PEG400?=?6: 4 as solvent. Atom economy, good to excellent yield, operational simplicity and easy workup are important features of this method.
Graphical abstractThe development of a versatile platform that can separate oil/water mixture, remove dye from water, and purify wastewater is extremely desirable, yet still hard to realize. Herein, to address this challenge, a composite hydrogel was produced by freezing–thawing treatment using chitosan, polyvinyl alcohol, and carbon black as the raw materials. The obtained hydrogel displayed both slippery oil-repellency and water-affinity in air, underwater, when submerged in oil, and exploiting this special wettability, the hydrogel coated mesh can be used to separate oil/water mixtures efficiently. After 25 oil–water separation cycles, the hydrogel-coated filter still had a separation efficiency of over 98%. With its superhydrophilicity and active functional groups, the resulting hydrogel was able to absorb dye molecules dissolved in water effectively. Due to the photothermal effect of carbon black, the local temperature of the hydrogel was increasing quickly under sunlight illustration, which allowed it to be an advanced platform for daily wastewater purification through solar distillation.
Graphical abstractA versatile hydrogel platform for oil–water separation, dye adsorption, and domestic wastewater purification was developed.
Exploitation of cotton fabric as electromagnetic interference (EMI) shielding substrates have attracted a growing interest due to their desirable low carbon footprint, economic feasibility, and sustainability. Herein, a facile strategy was proposed for preparing a cellulose-based multifunctional PNIPAAm/PPy hydrogel/cotton (PPHC) EMI shielding composites with simultaneous high-efficient electro-photo-thermal conversion and comfort regulation functions. The PPHC was fabricated via in situ polymerization conductive PPy hydrogel on cotton substrate followed by deposition of PNIPAAm. Benefiting from the unique interconnected three-dimensional networked conductive structure of PPy hydrogel, the obtained PPHC composites exhibited high conductivity (15 mS/cm), and EMI shielding effectiveness (EMI SE?~?40 dB) in the frequency of 8.2–12.3 GHz. Moreover, the PNIPAAm coating endowed the composite fabrics with adjustable wettability performance in response to external temperature, leading to excellent comfort regulation performance. This work provided feasible avenue toward low cost and sustainability cotton-based EMI shielding composites with efficient EMI shielding and comfort regulation performance.
Graphical abstractThe AHA coupling of amines, haloalkane and alkynes under UV visible light was achieved with a higher yield in the presence of Au/Fe2O3. The catalyst was prepared by two methods using different gold content and then characterized by XRD, UV–vis, BET, TEM, ICP-OES and TPR spectroscopies. A comparative study of the ordinary and photocatalytic conditions, showed that the UV visible light could activate the gold nanoparticles and lead to the formation of CH2Cl? and Cl? radicals through CH2Cl2 fragmentation. The propargylamine was afforded at low temperature and a short time using 2% Au/Fe2O3. The catalyst was stable for five cycles with good photoactivity.
Graphical abstractIn this work, a separation and purification process of U(VI), Zr(IV) and I2 from various fission products in nitric acid solution by 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C4mim][NTf2]) and dibutyl-3-(3-methylimidazolium)propylphosphoramide bis(trifluoromethanesulfonyl)imide-task specific ionic liquid (phosphoramide-TSIL) was investigated. The phosphoramide-TSIL was found to reduce ligand loss compared to dibutyl propylphosphoramidate by total organic carbon testing (TOC). The stripping of U(VI), Zr(IV) and I2 could be achieved by guanidine carbonate solution, oxalic acid solution and sodium hydroxide solution, respectively. The phosphoramide-TSIL/[C4mim][NTf2] showed good irradiation stability and recyclability. Phosphoramide-TSIL has the potential to be applied for separation and purification in the actual radioactive environment.
Graphical abstractWearable flexible sensors with quick response time and high stability are required in the fields of human motion detection, personal health monitoring, and artificial electronic skin. However, their design remains a challenge. To address this need, we fabricate a piezoresistive sensor with a wide detection limit, fast response time, and excellent stability in this work. Nickel (Ni) and copper (Cu) films are deposited on cotton fabric (CF) by in-situ polymerization of polyaniline (PANI) using magnetic filtration cathode vacuum arc deposition technology to obtain copper/polyaniline cotton (Cu/PANI/CF) and nickel/polyaniline cotton (Ni/PANI/CF). The pressure sensor is then fabricated by self-assembly. The proposed pressure sensor has a wide detection limit (0–180 kPa), rapid response time (30 ms), high cycle stability (>5000), and can detect the movement of each joint of the human body (such as the knee, finger, elbow, etc.). The sensor can also monitor different facial micro-expressions, including smiles and blinking. Based on the practical application of human motion signals and the detection of subtle stress, the proposed sensor demonstrates significant potential as a wearable electronic product for health monitoring.
Graphical abstractIn this, an efficient flame retardant composite has been prepared using biowaste derived phosphorous groups decorated graphene supported nanomaterial. The eggshell was utilized as a source of calcium carbonate, which was converted to monocalcium phosphate (CP) by phosphoric acid treatment. As-prepared monocalcium phosphate was functionalized with graphene to prepare graphene functionalized monocalcium phosphate (GCP). The GCP-coated fabric didn't ignite during the flame test and sustained more than 600 s on continuous exposure to flame without changing its initial length and shape. Whereas, graphene oxide (GO), and CP coated cotton fabric burnt out very easily within a short time. The efficient flame retardant property of as synthesized GCP coated cotton fabric was confirmed with a high limiting oxygen index (34.1) and char length of 2.5 cm was generated from the VFT test. The synthesized GCP coated cotton fabric also confirmed efficient flame retardant properties. This facile method enables an easy process for mass production of cost-effective, bio-waste derived nanomaterial for a significantly highly efficient candidate for different applications in sustainable chemistry, including flame-retardant applications.
Graphical abstractAluminum sacrificial anodes are currently the first choice for cathodic protection in numerous applications. The galvanic performance of aluminum-based sacrificial anodes is considerably enhanced by addition of certain alloying elements called activators. Recent researches proved that incorporation of specific metal oxides like MnO2, CeO2, RuO2, and IrO2 into the aluminum matrix could enhance the galvanic efficiency of aluminum anodes; however, the mechanism by which metal oxides improve galvanic properties of aluminum is still subject to discussion. The present work investigates the effect of incorporating commercially available low-cost manganese dioxide concentrate into Al-5Zn-0.1Sn sacrificial anodes in different volume fractions. It also studies the influence of heat treatment on anode’s galvanic performance by performing solution treatment at 3 different temperatures (250 °C, 400 °C, 550 °C). The electrochemical testing results proved an increase in efficiency of anodes incorporated with metal oxides and solution treated at 550 °C. The SEM imaging and EDX elemental mapping declared that the presence of SiO2 particles in the anode matrix which might cause effective and uniform corrosion of Al anodes and decreased non-coulombic losses.
Graphical abstractN-Methylpyrrolidine catalyzed, concise and attractive synthesis of a new class of 3-hydroxy-3,5/6-di-aryl-1H-imidazo[1,2-a]imidazol-2(3H)-ones was attained with impressive yields, in the presence of EtOH as a solvent, by means of a convenient and elegant condensation reaction between different aryl glyoxal monohydrates and guanidine hydrochloride under reflux conditions. Some specific merits of the current procedure, including encompasses low operating cost, availability of the starting substrates, reasonable reaction times, high reaction yield, operational simplicity, cleaner reaction profile, no harmful by-products, and the isolated product is in pure form. Structures of all the freshly synthesized products have been deduced by their FT-IR, 1H-NMR, 13C-NMR, Mass spectrometry data and microanalysis.
Graphical abstractMultifunctional materials for water purification have attracted significant attention due to the increased water pollution problems. However, fabricating the low-cost, effective, and recyclable separation material for wastewater containing various hazardous substances is still a challenge. Herein, we developed an Ag/TiO2@PDMS coated cotton fabric with self-cleaning ability, high flux, superior visible-light photocatalytic ability, and recyclability via the “powder?+?glue” strategy. The composites are superhydrophobic (water contact angle 157°) and show high separation efficiency. After 20 times of repeated use, the separation efficiency remains 16,322 Lm?2 h?1, and methylene blue (MB) 's degradation rate remains almost unchanged. The high oil purification, catalytic property, excellent stability in harsh conditions, and recyclability enable the material as a satisfactory candidate for water purification.
Graphical abstractThis study introduces an effective route to fabricate chitosan (CS)-based film. The films were prepared through cross-linking reaction between CS and hydroxyethyl cellulose (HEC) using epichlorohydrin (ECH) as the cross-linker and simultaneously in-situ loading with CuO nanoparticles. FT-IR and loading efficiency results indicated the occurrence of inter- and intra-molecular cross-linking reaction between CS and HEC. XRD and EDS analyses showed that the CuO nanoparticles were evenly deposited onto CS film matrixes. SEM characterization showed that the films were of compact, dense and uniform cross morphologies, as well as obvious voids. The films also exhibited desired swelling ratio and water vapor permeability. The enhanced tensile strength was obtained with a maximum value of 77.02?±?3.26 MPa, while the stretch-ability slightly decreased. The thermal stability of the films decreased after cross-linking with HEC. The antibacterial ability of the films was generally improved with the increase of HEC and ECH contents.
Graphical abstractPreparation and properties of epichlorohydrin-cross-linked chitosan/hydroxyethyl cellulose based CuO nanocomposite films
In this work, the electrochemical performance of Na-doped layered cathode material LiCoO2 for Li-ion batteries is studied using first-principles calculations. The results show that the doped Na ion acts as a pillar, which can greatly increase the diffusion rate of Li ions, but it is not conducive to improving cycle performance and delithiation potential. These research results provide a theoretical reference for the study of Li-ion batteries with high-rate performance. Due to the conflicting role of single element doping, the multi-element co-doping strategy will be the best way to develop high-performance Li-ion batteries.
Graphical abstractSub-2-µm sea-urchin-like TiO2 microspheres were prepared through the one-step solvothermal method. Results of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that there are a lot of nanorods coming out from the center of the TiO2 microsphere, making it look like a sea urchin. The morphology and structure of these microspheres are very suitable for chromatographic packing. During the separation of inorganic anions on this new stationary phase, the retention mechanism is electrostatic interaction, and the pH of the mobile phase plays an important role in retention behaviors. With this new stationary phase for separation of organic anions and nucleobases, Lewis acid–base interaction is more outstanding, which can cause peak broadening and tail for larger conjugated structure compounds. The separation of aromatic hydrocarbons on this new stationary phase demonstrates that Lewis acid–base interaction has a favorable influence on the separation of electron-rich aromatic hydrocarbons under normal phase chromatographic conditions.
Graphical abstractThe triethylamine-based nanomagnetic ionic liquid, [(Et)3 N-H]FeCl4, was synthesized, and its structural and chemical characteristics were detected. The thermogravimetric analysis indicated its high thermal stability with a decomposition temperature higher than 300 °C. Additionally, [(Et)3 N-H]FeCl4 was used to efficiently catalyze the synthesis of xanthene derivatives under solvent-free conditions at 120 °C. [(Et)3 N-H]FeCl4 was recycled and reused at least five times.
Graphical abstractLife-threatening diseases, especially those caused by pathogens and harmful ultraviolet radiation (UV-R), have triggered increasing demands for comfortable, antimicrobial, and UV-R protective clothing with a long service life. However, developing such textiles with exceptional wash durability is still challenging. Herein, we demonstrate how to fabricate wash durable multifunctional cotton textiles by growing in situ ZnO-TiO2 hybrid nanocrystals (NCs) on the surface of cellulosic fabrics. The ZnO-TiO2 hybrid NCs presented high functional efficiency, owing to their high charge transfer/separation. Ultrafine fiber surface pores, utilized as nucleating sites, endowed the uniform growth of NCs and their physical locking. The resulting fabrics presented excellent UV protection factors up to 54, displayed bactericidal efficiency of 100% against Staphylococcus aureus and Escherichia coli, and optimum self-cleaning efficacy. Moreover, the functionalized textiles exhibited robust washing durability, maintaining antibacterial and anti-UV-R efficiency even after 30 extensive washing cycles.
Graphical abstractIonic cellulose nanocrystals (CNCs) are interesting surface-active particles for encapsulating a lipophilic liquid in water. A CNC is modified chemically to a negative charge (an S-CNC) by surface treatment with sulfuric acid. Despite the amphiphilic nature of S-CNCs, it is difficult to determine the degree of substitution for emulsification of lipophilic liquids, especially when the surface energy is low and polarity is high. Here, we control the substitution of S-CNCs by desulfation of S-CNCs (dS-CNCs) using a low-concentration hydrochloric acid solution. Decreased surface charge of S-CNCs was expected, and the lipophilic affinity of dS-CNCs increased compared with those of S-CNCs. Six oils with differing surface tensions were selected for determination of the effect of charged CNCs on emulsification. The stability of the emulsion was evaluated by emulsion fraction, emulsion particle size, and surface tension of emulsified solutions from dS-CNCs and oils.
Graphical abstractActivated carbon paper-based materials were prepared from softwood pulp, activated carbon powder, and polyester fiber through wet forming process. Then polyethyleneimine was loaded on the activated carbon paper-based materials using physical impregnation method to fabricate green, low cost, and degradable PEI/activated carbon composite paper-based adsorbent materials (PPCA) for the removal of Cr(VI) from drinking water. The surface characteristics of the adsorbent were analyzed by SEM, EDX, BET, FT-IR, and XPS. It was found that the maximum adsorption capacity of Cr(VI) could reach up to 1.58 mg g?1 when the PEI immersion concentration is 1%, the contact time is 180 min, the temperature is 30 °C and pH?=?2. The adsorption of Cr(VI) on PPCA conformed to both the freundlich isotherm model and the quasi-second-order kinetic model, indicating that the adsorption was multi-molecular layer adsorption controlled by chemical reaction process. The adsorption mechanism of Cr(VI) on PPCA included electrostatic attraction, redox and chelation. Overall, this study provides a green, large-scalable production way for the preparation of biodegradable adsorption materials for the efficient removal of Cr(VI) from drinking water aiding the safe management of aqueous system.
Graphical abstractThe one-pot catalytic conversion of cellulose into ethylene glycol (EG) is an attractive way of biomass utilization. However, low-cost, efficient, and stable catalysts are the premise and research challenges of industrial application. Herein, the magnetic recyclable W–Ni@C catalyst was synthesized by in-situ pyrolysis of Ni-MOFs impregnated with ammonium metatungstate. Compared with the Ni-W bimetallic catalysts prepared by the impregnation method and the sol–gel method, the W–Ni@C catalyst for cellulose hydrogenolysis reaction can achieve a higher ethylene glycol yield (67.1% vs 43.3% and 42.6%) and 100% of cellulose conversion rate. The uniformly dispersed Ni nanoparticles and abundant defective WOx were formed in a reductive atmosphere generated in pyrolysis of Ni-MOFs, which was indispensable for the hydrogenolysis of cellulose into EG. Besides, the hierarchical porous carbon derived from organic ligands in Ni-MOFs reduces the mass transfer resistance while confining Ni nanoparticles and WOx to prevent their leaching, effectively enhancing the stability of the W–Ni@C catalyst. Therefore, the remarkable catalytic performance, the simple and effective recovery method as well as satisfying stability would make W–Ni@C become a promising catalyst for the conversion of cellulose to EG.
Graphical abstractA simple and efficient method for the synthesis of pyrazolopyranopyrimidines under solvent-free has been developed. The one-pot multicomponent condensation of arylaldehydes with hydrazine hydrate, ethyl acetoacetate and barbituric acid in the vicinity of a mesoporous basic nanomagnetic catalyst, namely DBU immobilized on Fe3O4@nSiO2@mSiO2 was synthesized in remarkably high yields and in short reaction times. Significantly, this catalyst can be easily separated from the reaction media by applying an external magnet, and can be reused for several cycles.
Graphical abstract