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A novel Fe/Co metal organic complex nanosheet modified by 1,4-dicarboxybenzene (BDC), i.e., FeCo@BDC, was prepared, and highly efficient removal performance for trace lead (II) (Pb2+) was demonstrated in the neutral aqueous solutions. The removal rates were higher than 95% and the adsorption was equilibrated in 15 min. The isotherms and kinetics for the adsorption Pb2+ by the FeCo@BDC adsorbents followed Langmuir model and pseudo-second-order model, respectively. The maximum adsorption capacity was 220.48 mg•g−1. The FeCo@BDC adsorbents also own a prominent regeneration performance. The prominent performance of in the removal of trace Pb2+ makes FeCo@BDC an ideal candidate as commercial adsorbent materials.

Precise control of value and dispersion characteristics of negative permittivity is still an unsolved problem in the practical application of random metamaterials. In this work, the ternary percolation nanocomposites (CNTs-GR-CCTO) were prepared via a low-temperature sintering process by using graphene (GR), carbon nanotubes (CNTs), and copper calcium titanate (CCTO). As the total carbon contents increased, the three-dimensional carbon network was formed, and negative permittivity is realized, which exhibits the Lorentz-type and Drude-type dispersion behaviors. The synergistic effect between GR and CNTs was studied in detail. While the GR sheets separate the CNTs, the CNTs also act as wires to connect the GR sheets. Controlled conductive paths were created by changing the ratio of CNTs to GR, achieving precise regulation of the negative permittivity, which is further certified by the equivalent circuit analysis. We provide a novel strategy for the precise regulation of negative permittivity of carbon-matrix metamaterials, which will greatly facilitate applications of metamaterials with negative permittivity. Precise regulation of weakly negative permittivity is achieved in CaCu3Ti4O12 metacomposites by synergistic effects of carbon nanotubes and graphene.

As a typical lightweight material, carbon materials have great application prospects in fabricating microwave absorbers. In this work, the Fe3C@Fe/C composites with porous microstructure are obtained by a simple and environmentally friendly method with wasted cornstalks as raw materials. The reflection loss of absorbing composites reaches the minimum value which is less than −50 dB when the thickness is 1.13 mm, while widest effective absorbing bandwidth reaches 5.1 GHz when thickness is 1.50 mm. The stalk-made nanocomposites’ excellent absorbing ability is mainly credit to excellent impedance matching and attenuation characteristics of composites, which is further credit to a synergistic influence of the dielectric loss from the multiple interfaces in porous microstructure and magnetic loss from iron nanoparticles. A low-cost method to obtain microwave absorption materials and realize high-value utilization of agricultural waste to reduce pollution caused by burning cornstalks is put forward.

A novel nanocomposite (WO3/UiO-66) was successfully synthesized by the microwave hydrothermal method. The influence of the W:Zr molar ratio on the WO3/UiO-66 structure was explored in detail, and the photocatalytic activity of the nanocomposite for photodegradation of rhodamine B (RhB) was evaluated. The WO3/UiO-66 with a W:Zr molar ratio of 1:5 (WO3/UiO-66–5) exerted the most excellent photocatalytic performance, and the photocatalytic efficiency reached 96.6% after 100 min of simulated sunlight irradiation, thereby showing a higher photocatalytic performance than pure UiO-66 or pure WO3. In addition, the stability and reusability of the nanocomposite were studied by cyclic experiments, and the degradation rate of WO3/UiO-66–5 still reached 86.6% after 5 cycles. The mechanism underlying the photocatalytic degradation of WO3/UiO-66 was finally studied by quenching tests, and the crucial factor in the RhB degradation was hole (h+), and the existence of the n–n heterojunction also promotes the degradation of RhB by nanocomposites. In this work, an effective method is provided for the preparation of photocatalysts that degrade organic dyes.

Among various environmental problems, water pollution has drawn more and more attention. To develop an adsorbent with enhanced selectivity and high capacity for As (V) oxyanion, a novel lignin-based adsorbent was prepared by doping with N and modifying with Mg2+, using thiethylenetetramine (TETA) and MgCl2 as the source of N and Mg2+, respectively. N-doped lignin (NL) shows a high selectivity for As (V), which is further enhanced by modifying with Mg2+ (MNL). MNL shows an excellent reusability. The adsorption isotherms and kinetics of MNL for As (V) follow Langmuir isotherms model and pseudo-second-order kinetics model, respectively. The adsorption of MNL for As (V) achieved a maximum adsorption capacity of 687.46 mg g−1 and the equilibrium was established within 30 min. This study offers a novel idea on the recycle of the waste of paper industry and provides a new technology for As (V) adsorption from wastewater.

A major issue limiting the thermal conductivity (TC) of polymer-based composites is the inevitable vacancy among thermal conductive fillers; the fabrication of continuous thermal conductivity network is significant. In this work, we successfully constructed interpenetrating carbon nanotube (CNT) @carbonized polyvinyl alcohol (αPVA) network in polyimide (PI)/boron nitride nanosheets (BNNS) membranes through co-electrostatic spinning of polyamide acid (PAA)/BNNS precursor fibers and PVA/CNT precursor fibers and subsequent high-temperature treatment. The CNT @αPVA network works as a continuous thermal conductivity network in the membrane, which could also bridge BNNS to remove the vacancies among BNNS fillers. Due to the formation of dual thermal conductive networks, the TC of PI/BNNS with 30 wt% BNNS reached an increasement of 100% with the addition of only 0.3 wt% CNT. In addition, the composites present electrical insulating properties with volume resistivity of about 1015 Ω·cm, as well as excellent flexibility, pretty good acid–alkali tolerance, and self-extinguishing. This work provides an effective way to develop continuous thermal conductive networks in polymer-based composites for scalable thermal management applications in microelectronics devices.

In this study, a Surlyn resin ionic interlayer was prepared. Its thermal stability, crystallization, and dynamic mechanical properties were tested, and the thermal stability and crystallization properties of the material were compared with SentryGlas® Plus (SGP) and polyvinyl butyral (PVB) interlayers. The experimental results show that the thermal stability and crystallinity of the ionic interlayer are very close to the SGP interlayer, both of which belong to ionomers, and the performance of the ion interlayer is better than that of the PVB interlayer. Laminated glass was prepared using ionic interlayer and PVB interlayer and tested for light transmittance and bending resistance. The laminated glass with the ionic interlayer film had higher light transmittance than the PVB laminated glass, and the bending strength was more than twice that of the laminated glass with the PVB interlayer. These results show that the Surlyn resin has the potential to replace SGP as interlayers in the laminated glass.

Co3O4 nanorods were successfully synthesized by a facile two-step method and showed outstanding electrochemical performances in KOH and urea electrolyte. The Co3O4 nanorods showed high purity phase and covered the surface of carbon cloth. As the electrode materials for hydrogen generation, it only required the hydrogen evolution reaction (HER) overpotential of 0.46 V to deliver the current density of 40 mA/cm2 for HER and urea oxidation reaction potential (UOR vs RHE) of 1.62 V at 10 mA/cm2. Remarkably, the assembled electrolyzer with Co3O4/CC and Pt foil as two electrodes demonstrated low potentials and a stable long cycle life. Therefore, the study displays a promising direction to explore the practical and effective ways for hydrogen production by overall urea electrolysis.

Abuse of antibiotics in animal husbandry and medicine has led to severe environmental problems especially the risk of bacterial resistance. Different from common organic pollutants, antibiotics in ...

Postmeiotic spermatids use a unique strategy to coordinate gene expression with morphological transformation, in which transcription and translation take place at separate developmental stages, but how mRNAs stored as translationally inert messenger ribonucleoproteins in developing spermatids become activated remains largely unknown. Here, we report that the RNA binding protein FXR1, a member of the fragile X–related (FXR) family, is highly expressed in late spermatids and undergoes liquid-liquid phase separation (LLPS) to merge messenger ribonucleoprotein granules with the translation machinery to convert stored mRNAs into a translationally activated state. Germline-specific Fxr1 ablation in mice impaired the translation of target mRNAs and caused defective spermatid development and male infertility, and a phase separation–deficient FXR1 L351P mutation in Fxr1 knock-in mice produced the same developmental defect. These findings uncover a mechanism for translational reprogramming with LLPS as a key driver in spermiogenesis.

The nitrogen-doped carbons (NC) were prepared by a simple pyrolysis method using polyaniline as the precursor. The effect of carbonization temperature on the properties of the synthesized NC was investigated. The optimal temperature was determined as 600 °C according to the properties of the obtained materials and the performance on improving the methane production by the anaerobic sludge. When the optimal NC was used as the conductive medium in the anaerobic sludge, the methane yield and production rate were increased by 35% and 10%, respectively. The effect of the NC loading on the activity of the microorganisms was also investigated. It was found that the degradation of the organics in the bacteria was enhanced by adding NC. Moreover, the bacterial and archaeal communities were significantly affected by the added NC material, and Methanosaeta with the direct interspecific electron transfer (DIET) ability have been enriched in anaerobic sludge. This indicated that the NC materials with surface defects can improve the organics degradation and the microbial extracellular electrons transfer, thereby promoting the methane production during the anaerobic wastewater treatment.

We report for the first time using zinc hydroxyfluoride (ZnOHF) for efficient NO2 gas detection. The prepared ZnOHF had a unique flower-like architecture self-assembled by nanorods with a diameter of 150 nm and length of 2-3 μm. The sensing performance toward NO2 detection indicated that the prepared ZnOHF exhibited high response (82.71), short response/recovery time (13 s/35 s) to 10 ppm of NO2, and excellent selectivity at 200 °C, greatly outperforming the ZnO raw material. ZnOHF could work in a wide detection window ranging from 100 ppb to 50 ppm, implying its practical application prospects in both industry and daily life. The excellent sensing behavior of ZnOHF originated mainly from the negligible oxygen ions adsorbed on the material surface, which was caused by the higher work function of ZnOHF. Therefore, almost all conduction band electrons can be used in the NO2 gas sensing.

The rapid development of electronic devices have brought increased concern on electromagnetic radiation (EMR) problems. The radiated EM waves can not only affect the normal operation of devices, but also threat people’s health. The most effective way to solve the EM pollution is to fabricate electromagnetic interference shielding materials (ESMs) and microwave absorption materials (MAMs) with lightweight, strong attenuation ability, and excellent mechanical stability. In this case, carbon materials and their nanocomposites attracted great attentions in the fields of electromagnetic interference (EMI) shielding due to the advantages of low density, natural abundance, easy preparation, excellent conductivity and flexibility. In this review, we firstly carried out a summary of recent achievements for carbon materials with different microstructures as ESMs/MAMs during the past five years. It is found that 3D carbon materials such as foams, sponges, and aerogels, as well as their composites are favorable for enhancing the EMI shielding efficiency. Then we introduced the latest progress of novel composites including MXene/carbon composites and metal organic frameworks (MOFs) derived porous carbon nanocomposites. In the end, current challenges and prospects were proposed toward the development of carbon based materials as ESMs/MAMs, which indicated the trend and key point for future research.

Free-standing nanocellulose/ZIF-67 derived porous Co3O4 polyhedron hybrid dual-layer films were layer-by-layer successfully assembled by a water-based paper-making process. Nanocellulose (NFC) not only served as flexible substrate, but also it substituted expensive polymer binders to reduce the cost in the dual-hybrid film electrodes. Besides, the NFC/porous Co3O4 polyhedron composite (NPC) layer replaced the traditional metal current collector to be a free-standing electrode. The flexible NPC-60 film electrode (the ratio of porous Co3O4 polyhedron to NFC component was 60:30) had a higher capacitance (594.8 mF cm−2 at 5 mV s−1 in 6 M KOH) than other samples, and a power density of 799.97 W·kg−1 at the energy density of 18.75 Wh·kg−1. With the increase of NFC content, the hybrid film can be bent and rolled demonstrating that the hybrid film has good flexibility and foldability. This work provides an insight perspective for metal organic framework (MOF)-derived metal oxide powders to form flexible and free-standing supercapacitor electrodes.

Counter electrode at the cathode side of sensitized solar cells (SSCs) plays a critical key role in determining the device performance. Active and stable counter electrodes that can work over a wide range of electrolyte systems are highly desired for SSCs. Here, we report a mixed ternary pentlandite, Ni3Co6S8, as an efficient multifunctional counter electrode for SSCs with various redox mediators (I3−/I−, T2/T−, Co(bpy)33+/2+ and Sn2−/S2−). Ni3Co6S8 shows not only similar catalytic activity to Pt for I3−/I− redox shuttle but also superior catalytic activity for T2/T−, Co(bpy)33+/2+, and Sn2−/S2− redox mediators. Furthermore, SSCs assembled with Ni3Co6S8 also exhibit good performance preservation in conjunction with various electrolyte systems. This work highlights that SSCs are fully compatible with pentlandites and paves the way towards the realization of high efficiency and stable SSCs. Ni3Co6S8 demonstrates excellent catalytic activity towards various redox mediators, highlighting the full compatibility of pentlandites with sensitized solar cells.

In this paper, the pH value effect of phosphating solution on the formed phosphate conversion coatings (CCs) has been studied for the corrosion behavior of AZ91D. The electrochemical tests have been processed on the CCs fabricated under different pH values of phosphating solution. Morphological evolution and composition of the coatings, as a function of pH value, were examined by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XRD). The width and distribution area of micro-cracks on the surfaces were measured and statistical analyzed by an image-pro-plus software. Moreover, potentiodynamic polarization test, electrochemical impedance spectroscopy analysis, and immersion test were used to evaluate the corrosion property of the phosphate CCs in 3.5% NaCl solution. The dimension of the micro-cracks decreased with the increase of the value of pH. The CCs fabricated under the pH value of 4.0 showed the best corrosion resistance and the width and distribution area of micro-crack on the CCs were the minimum (0.78 (± 0.08) μm and 1253 (± 140) μm2, respectively). The self-corrosion current of the CCs was the minimum (2.85 μA/cm2), and the radius of capacitance arc in the electrochemical impedance spectroscopy was the maximum. The corrosion rate in immersion test also was the lowest. This study shows an alternative for the metal corrosion. Different pH values of phosphating solution on corrosion behaviors of phosphate conversion coatings on AZ91D were investigated.

We successfully synthesized nanoflower-like δ-MnO2, rod-shaped MnOOH, nano-small granular Mn3O4, and the cuboidal and spindle shaped MnCO3 via a facile one-pot hydrothermal method by adjusting the concentration of two sorts of short-chain surfactants with special catechol structures (3-Hydroxytyramine hydrochloride (DA) and 3,4-dihydroxybenzenepropanoic acid (DHCA)) in KMnO4 solution. The XRD and FTIR data demonstrated that the crystal form, morphology and size of the crystal were controlled by small molecule ligands. Afterwards, the relationship between manganese oxides and electrochemical properties was further explored. The results illustrated that nanoflower-like δ-MnO2 with layer structures have the highest specific capacitance of 307.4 F g−1 at a scan rate of 5 mV s−1.

The purification of wastewater, including heavy metals (Cu2+, Cd2+, Pb2+, and Zn2+), was investigated using the coconut shell-based activated carbon that the different agents modified of acid, alkali, potassium permanganate, and iron salt. Several effects using the modified coconut shell-based activated carbon were observed through the experimental characterization. First, the shortened time of adsorption equilibrium to heavy metal ions, reduced addition of carbon absorbents, and improved removal purification was observed. Second, the agents of acid and potassium-modified coconut shell-based activated carbon showed improved removal rate on heavy metal wastewater containing Zn2+ with up to 95% and 96.5%, respectively. Alkali modification showed the highest removal effect on wastewater containing Cd2+ with 98%, and the iron-salt modification improved the adsorption capacity most for Pb2+ with 92%. Third, the increase of the adsorption reaction time and the amount of adsorbent showed a direct relationship to the adsorption effect. Saturated adsorption to reach an equilibrium was observed as the reaction time exceeded. Among agents, acid, alkali, and potassium specifically had a better impact on the purification than iron salt. With a 1-g dosage of adsorbent, three agents successfully removed more than 90% of the wastewater pollutants. Also, weak acidic conditions with pH = 5 showed more effect on removing heavy metal ions. Purification of heavy metals in wastewater using the coconut shell-based activated carbons with experimental verification.

Carbon-based composites have gained extensive attention as microwave absorbing materials due to the lighter weight compared with other materials. In this work, Co/C nanocomposites with Co nanoparticles uniformly distributed in amorphous carbon sheets are prepared by a freezing dry and carbothermic reduction process. Hierarchical porous microstructures (micropores, mesopores, macropores) are achieved by ice template and huge amounts of gas during carbothermal reduction. Excellent absorption performance is achieved at a very low Co/C content (10% and 15%), which is a great success to design ultralight absorbers. At 10% content level, the effective absorption bandwidth is 5.0 GHz with a thin thickness of 1.8 mm, while the absorption bandwidth is 4.7 GHz with a thin thickness of 1.5 mm at 15% Co/C content level. The excellent absorption performance is attributed to excellent impedance matching resulting from synergy of cobalt and carbon and strong interfacial polarization induced by the hierarchical porous microstructures. This work provides a new pathway of designing ultralight absorbers with the advantage of thin thickness and wide bandwidth. Excellent absorption performance is achieved at only 10% Co/C content level, a success to design ultralight absorbers.

With very fast polymerization in mild reaction conditions and unique characteristic of double bonds in its synthesized polymer skeleton for further modification and functionalization, ring opening ...

Hydroxy-terminated polybutadiene/toluene diisocyanate (HTPB/TDI) binder system is widely used in composite solid propellants. Expiration of weapons and ammunitions results in a significant amount of abandoned propellants. After recovery of energetic components, biodegradation is a potential treatment technology for the remaining material to convert into a harmless substance with low molecular weight. Due to high molecular weight and the presence of carbon-carbon long chain segments lacking electronegative elements, this binder system is difficult to be biodegraded. Nevertheless, some pretreatments will improve biodegradation. A two-step pretreatment of the binder system was performed using CH3-ONa/CH3-OH as a depolymerization reagent and HCOOH/H2O2 as an epoxidizing reagent so as to obtain an initial substrate for biodegradation. FT-IR and GPC analyses show that depolymerization breaks the urethane bonds in the binder system, and the hydroxyl-terminated depolymerization product has a structure similar to that of HTPB and significantly reduced molecular weight close to that of HTPB. Subsequent epoxidation makes some carbon-carbon double bonds in the hydroxyl-terminated depolymerization product convert into epoxy groups. The biodegradability tests show that there are richer potential degrading microorganisms for the epoxidation product as the sole carbon source vs. the original binder system, and the epoxidation product has a higher weight loss in biodegradation. As a pretreatment, depolymerization and epoxidation can reduce the molecular weight of substrate, improve the hydrophilicity, and make the biodegradability of pretreatment product superior to the HTPB/TDI binder system.

The synergist of phosphorus and silicon-containing benzoxazine (p-BOZ) was prepared through three steps using phenylphosphonic dichloride, 3-aminopropyltriethoxysilane, and 4-methoxyphenol as raw materials. The structure of p-BOZ was demonstrated by 1H NMR. Ammonium polyphosphate (APP) and melamine (ME) were compounded to form an intumescent flame-retardant (IFR) system that can remarkably improve the flame retardancy of polyoxymethylene (POM). The performances of APP/ME/p-BOZ and the related mechanisms were studied by employing limited oxygen index (LOI), UL 94 rating, cone calorimeter test (CONE), thermogravimetric analysis (TGA), Raman spectral analysis, and scanning electron microscope (SEM). The results showed that the introduced p-BOZ can effectively enhance the char formation ability of the APP/ME/p-BOZ system in the condensed phase and improve the gas-phase performance simultaneously. The POM composites containing 2 wt% p-BOZ compounding with 20 wt% APP and 6 wt% ME reached UL94 V-0 rating and a LOI value of 42.8%. Meanwhile, average HRR, MLR, EHC, SEA, and TSP of the composite all exhibited significant reduction, further conforming that p-BOZ can act as an effective flame-retardant synergist and a smoke suppressant. The synergist of phosphorus and silicon-containing benzoxazine (p-BOZ) was prepared. The POM composites containing 2 wt% p-BOZ compounding with 20 wt% APP and 6 wt% ME reached UL94 V-0 rating and a LOI value of 42.8%.

With the rapid development of highly integrated electronic systems, microstructure heat exchangers have attracted more and more attentions according to their advantage of space saving, which can be utilized for the thermal dissipation in high power consumption systems with space limitation. As an important part of microstructure heat exchangers, the research on metal-polymer composite heat exchangers are still not systemic enough. Herein, the influences of several factors, including surface roughness, heating power, structural type of junction surface, thermal conductivity, and installation direction, on thermal conductive properties (e.g., thermal resistance, thermal dissipation performance) of metal-polymer composite microstructure heat exchangers are studied systematically based on the thermodynamic theory. The microstructure heat exchangers provide same thermal dissipation performance using only one-fifth spatial volume of the conventional heat exchangers. Both numerical and experimental methods are performed in this study, and the results are in good agreement. The metal-polymer composite microstructure heat exchangers could become good substitutes of conventional ones attributed to their smaller space requirement.

Supramolecular polymers have the combined properties of both traditional polymers and supramolecules. They are generally formed via the self-assembled polymerization driven noncovalent interactions such as hydrogen bonding, π-π stacking, metal coordination, and host-guest interaction between building blocks. The driving force for the formation of supramolecular polymers has changed from single noncovalent interactions to multiple noncovalent interactions. The advantages of multiple noncovalent interactions driving the formation of supramolecular polymers are reviewed from four aspects: polymer construction, the enhancement of bonding strength, properties and topological structure. The applications are illustrated with detailed examples including self-healing, drug delivery, bioimaging, biomedicine, environmental sensing and electronics.