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Abstract: Silkworms have been developed over thousands years to optimize folding and crystallization of fibroin under highly controlled conditions which have resulted in their efficient fiber formation. In this paper, we reconstructed the three-dimensional architecture of the spinneret of a wild silkworm Samia cynthia ricini from approximately 1000 optical micrographs of the semi-thin cross sections. The chitin plates and muscles were observed in the silk press part together with large change in the diameter of the spinneret lumen at the press part by large shear stress. This is similar to the case of the spinneret of Bombyx mori silkworm, indicating that the structural change in the silk fibroin of S.c. ricini silkworm occurs exclusively at the silk press part due to large shear stresses. Molecular dynamics (MD) calculations were then performed to study the structural change that occurs in the crystalline region of S.c. ricini silk fibroin under shear stress. Namely, using the peptide AGGAGG(A)12GGAGAG as a model of the crystalline part of the silk fibroin under different shear stresses in the presence of water molecules and followed by molecular mechanics (MM) calculation after removal of water molecules. The simulation indicates that the Ala residues in the model peptides adopt a predominantly β-sheet structure under shear stresses of above 1.0GPa. [Copyright &y& Elsevier]

High thermostability of phase change materials is the critical factor for producing phase change thermoregulated fiber (PCTF) by melt spinning. To achieve the production of PCTF from melt spinning, a composite phase change material with high thermostability was developed, and a sheath-core structure of PCTF was also developed from bicomponent melt spinning. The sheath layer was polyamide 6, and the core layer was made from a composite of polyethylene and paraffin. The PCTF was characterized by scanning electron microscopy (SEM), thermal analysis (TG), Fourier Transform Infra-Red (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and fiber strength tester. The results showed that the core material had a very high thermostability at a volatilization temperature of 235 °C, the PCTF had an endothermic and exothermic process in the temperature range of 20–30 °C, and the maximum latent heat of the PCTF reached 20.11 J/g. The tenacity of the PCTF gradually decreased and then reached a stable state with the increase of temperature from −25 °C to 80 °C. The PCTF had a tenacity of 343.59 MPa at 0 °C, and of 254.63 MPa at 25 °C, which fully meets the application requirements of fiber in textiles. [ABSTRACT FROM AUTHOR]

[Display omitted] • Shish-kebab (SK) structures grown on PLA/PAN@PLA/PVDF Janus membranes. • SK structure improves hydrophobicity of the PLA-based electrospinning membranes. • Janus-SK membrane simultaneously enhances water transport rate and interfacial binding. • SK structure promotes efficient oil-water separation. Janus membranes are widely used in fields such as oil-water separation and wound dressings due to their asymmetric wetting properties. However, the weak interface binding force between the hydrophobic and hydrophilic layers can affect the liquid transport performance and membrane separation. In this study, we have reported a method using self-induced crystallization to grow shish-kebab (SK) structures in electrospinning polylactic acid-based fiber membranes. Peel testing revealed that the peel load after induced crystallization increased from 0 to 0.05 N to 0.05–0.15 N, and the time for droplets to penetrate from the hydrophobic side to the hydrophilic side decreased from 16S to 3S. This indicates that SK structures can enhance the adhesion between the hydrophilic and hydrophobic interface, as well as facilitating droplet transport. Through the oil-water separation experiment, it was discovered that the presence of SK structures can filter out more microemulsions. For different emulsions (kerosene, petroleum, n-hexane, petroleum ether, tea tree oil), the separation efficiency of Janus-SK membrane increased by 1.67 %, 2.5 %, 3.0 %, 9.7 %, 4.3 %, respectively. The development of Janus membranes has been provided with a new direction. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) are micro/mesoporous crystalline materials with high surface area, tunability, and compositional diversity and have been widely used in diverse applications, including catalysis. The rigid framework built from organic and inorganic functional structures can offer the merits of both, providing a platform to convert solar energy into usable or storable energy. Various approaches such as bandgap engineering, modulating the charge separation and increasing the intrinsic activity have been developed to improve the photocatalytic performance. This frontier article summarizes the current state-of-the-art in the use of MOFs as photocatalysts, emphasizing the recent strategies to optimize their visible-light-driven catalytic activities. Hopefully, this review could foreshadow new guidelines for explaining the current interest in exploiting novel MOF-based photocatalysts. [ABSTRACT FROM AUTHOR]

Examines the molecular conformation of the silk fibroin produced by the silkworm with the use of solid-state nuclear magnetic resonance spectroscopy. Conversion of the synthetic model peptide and the quasi-crystalline fraction of the fiber by formic acid treatment; Factors that contribute to the suggestion made regarding the heterogenous structure of the silk fiber.

Ternary nanocomposites including cellulose nanocrystals/silver nanohybrids (CNC-Ag) and biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) were prepared by using solution casting. The effect of different AgNPs contents in the nanohybrids on crystallization ability and properties of PHBV was comprehensively investigated. Compared to binary PHBV/CNC nanocomposite, the ternary nanocomposites with high AgNPs contents showed larger improvements in the thermal stability, mechanical, barrier, overall migration and antibacterial properties. The property transitions at various AgNPs contents were due to transition of the nanohybrids induced PHBV crystallization ability (from single CNC nucleation to synergistic nucleation of CNC and AgNPs), and increased crystallinity without compromising the amounts of hydrogen bonds. Especially, the PHBV/CNC-Ag-1.7 showed the good barrier property and lower migration levels in food simulants, high antibacterial ratio of 99.9% and biocompatibility to human MG-63 cells, suggesting its potential application in food packaging related materials. [ABSTRACT FROM AUTHOR]

Expanded graphite (EG) has been used to store phase change materials (PCM) to enhance thermal conductivity and avoid leakage. However, systematic investigation on physical structure of various embedded PCMs in EG is not reported. Besides, the effect of environment on thermal behavior of PCM/EG composites has not been investigated yet. In this work, three common PCMs (including myristic acid (MA), polyethylene glycol (PEG) and paraffin wax (PW)) were embedded in EG and three PCM/EG composites were obtained. As a result, capillary force between EG and PCMs supported encapsulation of PCMs in EG. PCM/EG composites had narrower phase change range while supercooling degree values were different when various PCMs were used. Besides, the hot and humid environment had a side effect on thermal energy storage of PCMs and PCM/EG composites. The inherent hydrophilicity of PCMs was essential for resistance against side effect of moisture on thermal energy storage. [ABSTRACT FROM AUTHOR]

The emergence of lamellar nanofluidic membranes offers feasible routes for developing highly efficient, mechanically robust, and large‐scale devices for osmotic energy harvesting. However, inferior ion permeability associated with their relatively long channels limits ionic flux and restricts their output performance. Herein, a superstructured graphene oxide membrane is developed to allow programmable topological variation in local geometry and contain laminar spaces inside. Such deliberate design offers excess specific area as well as nanofluidic channels to modulate transmembrane ionic transportation while concomitantly retaining similar nanoconfined environment in contrast to planar ones, leading to considerable enhancement of ionic permeability without compromising selectivity. This can be highly favorable in terms of osmotic energy harvesting, where the superstructured membranes offer a power output much higher than those of conventional planar ones. Besides, the superstructure design also endows the resulting membranes with benign biofouling resistance, which can be crucial to their long‐term usage in converting osmotic energy. This study highlights the importance of membrane topographies and presents a general design concept that could be extended to other nanoporous membranes to develop high‐performance nanofluidic devices. [ABSTRACT FROM AUTHOR]

Most amino acid molecules have good water solubility and are rich in functional groups, which makes them a promising derivatizing agent for cellulose. However, self-condensation of amino acids and low reaction efficiency always happen during esterification. Here, amino acid hydrochloride ([AA]Cl) is selected as raw material to synthesize cellulose amino acid ester (CAE). Based on TG-MS coupling technology, a significantly faster reaction rate of [AA]Cl compared to raw amino acid can be observed visually. CAE with the degree of substitution 0.412–0.516 is facilely synthesized under 130–170 °C for 10–50 min. Moreover, the effects of amounts of [AA]Cl agent, temperature, and time on the esterification are studied. The CAE can be well dissolved in 7 wt% NaOH aq., resulting in a 7.5 wt% dope. The rheological test of the dope demonstrated a shear-thinning behavior for Newtonian-like fluid, and a high gel temperature (41.7 °C). Further, the synthesized products show distinct antibacterial activity and the bacteriostatic reduction rate against E. coli can reach 99.5 %. This work presents a new method for cellulose esterification using amino acid hydrochlorides ([AA]Cl). [AA]Cl were well adsorbed to cotton pulp through dipping, and esterification facilely occurred by heating their mixture. No protective agent was added and self-condensation side reaction was avoided. In particular, the online TG-MS instrument visually demonstrated a significantly increased esterification rate. The result of cellulose ester showed good solubility in dilute alkaline solution and antibacterial activity. [Display omitted] • A derivatization method of cellulose using amino acid hydrochloride is presented. • TG-MS test demonstrates a significantly increased reaction rate of the method. • Rheological tests prove that modified cellulose can be dissolved in NaOH aq. • The resulted products show distinct antibacterial activity after derivatization. [ABSTRACT FROM AUTHOR]

Green, multifunctional protective fabrics have evoked enormous research enthusiasm because of the progress in public safety. Herein, inspired by the self-protection ability of natural creature, multifunctional protective cotton fabric (TP-Cotton) was prepared through layer-by-layer self-assembly of tannic acid (TA) and phytic acid (PA) from biomass. Due to the synergistic effect of TA as an antioxidant and PA as a fire retardant, the modified cotton fabric displays excellent fireproofing, antimicrobial activity, and UV-resistance. The limiting oxygen index of TP-Cotton reaches 39.4%, and the peak value of heat release rate (pHRR) reduces by 80.04% compared with Cotton. Moreover, the antibacterial rates of TP-Cotton against S. aureus and E. coli reaches 99.98 and 100.00%, respectively. Meanwhile, the ultraviolet protection factor value is over 40 due to the integration of TA, which is rich in phenolic hydroxyl groups. Therefore, benefiting from this unique composition and the simple preparation strategy, the as-prepared cotton fabrics showed highly multiple protection capabilities, having promising applications as protective clothing, military uniform, and overalls for emergency services. [ABSTRACT FROM AUTHOR]

[Display omitted] • LDO/vinasse biochar composite was synthesized for phosphate recovery and reuse. • LDO@BC 0.1 exhibits an ultra-high specific surface area of 508.97 m2/g. • LDO@BC 0.1 displays excellent removal capacity for trace phosphate. • P-adsorbed LDO@BC can be used as fertilizer to accelerate plant growth. In this work, CaMgAl-layered double oxide/biochar (LDO@BC) composites were elaborated by hydrothermal coprecipitation and calcination for the efficient recovery of phosphate as well as the further application of the reclaimed composites as fertilizers. On the one hand, the appropriate selection of biochar derived from vinasses as the substrates could solve the limitations of LDO like low specific surface areas as well as poor dispersion. The obtained composites possess the ultrahigh specific surface area as high as 508.97 m2/g. Therefore, a maximum adsorption capacity of 153.64 mg/g is achieved. In addition, our composites are with fast adsorption rates that nearly 100 % phosphate could be removed within 60 s at a trace concentration owing to the large specific surface areas. On the other hand, the recovered adsorbents could be used as fertilizers because of the high contents of P, Ca and Mg elements. The phosphate-adsorbed LDO@BC (P-LDO@BC) demonstrated a positive fertilization effect, significantly accelerating plant growth with length increment by 0.75 times and mass increment by 2.09 times compared with the control groups. Thus, this work not only provides a new approach for waste vinasse utilization, but also presents a promising adsorbing material for phosphate recovery and reuse. [ABSTRACT FROM AUTHOR]

Although many methods have been developed to create porous structures within polyelectrolyte films, it remains a challenge to conveniently define the spatial distribution of these structures. Herein, a simple, universal strategy with a high flexibility in programming porous regions throughout polyelectrolyte films is reported. This strategy is performed with the aid of laser scanning and the emergence of porous regions precisely tails after the moving path of laser beams. Quite different from previous strategies, the pore‐forming mechanism relies on laser‐triggered generation of gas to foam the films, which can be regulated by the content of photo‐sensitive groups, the intensity of laser beams, and the supramolecular interactions between polyelectrolyte chains. A prerequisite to succeed the foaming of polyelectrolyte films is to irradiate them under water, where the mobility of polyelectrolytes is activated to accommodate the pore formation within the films. Although many pore‐forming mechanisms involve aqueous systems, the porous structures here can be well preserved during drying procedures, which is hardly realized for conventional methods due to the formation of capillary pressure. The resulting polyelectrolyte films with patterned porosity can be quite useful in many fields, including but not limited to information display, surface wettability, and cell behavior manipulation. [ABSTRACT FROM AUTHOR]

Although many methods have been developed to create porous structures within polyelectrolyte films, it remains a challenge to conveniently define the spatial distribution of these structures. Herein, a simple, universal strategy with a high flexibility in programming porous regions throughout polyelectrolyte films is reported. This strategy is performed with the aid of laser scanning and the emergence of porous regions precisely tails after the moving path of laser beams. Quite different from previous strategies, the pore‐forming mechanism relies on laser‐triggered generation of gas to foam the films, which can be regulated by the content of photo‐sensitive groups, the intensity of laser beams, and the supramolecular interactions between polyelectrolyte chains. A prerequisite to succeed the foaming of polyelectrolyte films is to irradiate them under water, where the mobility of polyelectrolytes is activated to accommodate the pore formation within the films. Although many pore‐forming mechanisms involve aqueous systems, the porous structures here can be well preserved during drying procedures, which is hardly realized for conventional methods due to the formation of capillary pressure. The resulting polyelectrolyte films with patterned porosity can be quite useful in many fields, including but not limited to information display, surface wettability, and cell behavior manipulation. [ABSTRACT FROM AUTHOR]

Positively charged and non-toxic intermediate layers are highly desirable for the construction of nanofiltration membranes in the field of Mg2+/Li+ separation. Herein, we have prepared dual-electric layer nanofiltration membranes via introducing positively charged quaternized cellulose nanocrystals (Q-CNC) beyond the negatively charged polyamide skin layers. On the one hand, the strong interactions between Q-CNC and piperazine (PIP) could regulate the thickness, roughness, and residual groups of the polyamide (PA) layers, resulting in improved water flux. On the other hand, the Q-CNC has lots of positive charges which are beneficial for enhancing the rejections of negatively charged polyamide skin layers towards divalent cations since the Donnan and electrostatic effects are long-range forces. Moreover, this effect could be amplified by reducing the thickness of skin layers or decreasing the contents of residual carboxyl groups via adjusting the monomer concentrations. The obtained nanofiltration membranes possess high water flux of 51 L/m2/h/bar, and rejection for MgCl 2 of 86 %. The separation factor of Mg2+/Li+ is 29 when the Mg2+/Li+ mass ratio in the feed solution is 20:1. Moreover, the nanofiltration membrane with Q-CNC intermediate layers (QNFM) has good antibacterial properties, showing great potential in the fields of lithium extraction from salt lakes. [Display omitted] [ABSTRACT FROM AUTHOR]

Novel in-situ freeze polymerization assisted layer-by-layer self-assembly method was used to prepare robust regenerated cellulose fiber-polypyrrole (RCF-PPy) composite fibers with high-conductivity, where transverse-longitudinal polypyrrole growth on RCF was regulated by using Lewis acid FeCl 3 in crystalline ice state with the template etching and oxidation effects. [Display omitted] • In-situ freeze polymerization assisted layer-by-layer assembly achieved high-conductivity composite fibers. • Modulate transverse-longitudinal PPy growth on RCF was regulated by FeCl 3 in crystalline ice state. • RCF-PPy3 formed continuous and stable conductive networks using low concentrations PPy. • RCF-PPy3 displayed high strength and exceptional durability. • RCF-PPy3 sensor was designed into various multifunctional intelligent textiles. Novel in-situ freeze polymerization assisted layer-by-layer self-assembly method was utilized to prepare robust regenerated cellulose fiber-polypyrrole (RCF-PPy) composite fibers with high-conductivity, where transverse-longitudinal polypyrrole growth on RCF was regulated by using Lewis acid FeCl 3 in crystalline ice state with the template etching and oxidation effects. The RCF-PPy3 exhibited high strength (1.01 cN/dtex) and exceptional durability, withstanding mechanical deformation, friction (100 cycles), and ultrasonic washing (50 times), addressing the issues of poor interface adhesion and conductivity stability of conductive fibers. Furthermore, the composite fiber demonstrated high electrical conductivity of 87.66 mS cm−1 and outstanding sensing performances for monitoring strain, pressure, temperature (0.34 %/°C), and humidity (0.895 %/RH). Based on RCF-PPy3, a pressure sensor was constructed as a human–machine interface electronic device, achieving sedentary reminders, fingertip information transmission, indicating great potential applications in intelligent wearable fiber electronic devices. [ABSTRACT FROM AUTHOR]

Our photocatalyst possesses homo/heterojunction structure, which consists of hexagonal CdS, cubic CdS and Prussian blue. This design of homo/heterojunction structure not only achieves ideal energy band structure, which makes for stable and rapid separation of photogenerated electrons-holes, but also improves stability of photocatalyst in various extreme circumstances. Therefore, the photocatalytic activity is significantly enhanced. [Display omitted] • The homo/heterojunctions structures were designed via one-pot kinetic regulation. • The rational energy band distribution enhances photocatalytic activity. • The strong chelation between cyanogroups and Cd2+ improve the stability. • The photocatalysts possess excellent reusability. Photoreduction of soluble U(VI) to insoluble U(IV) by CdS-based catalysts shows great potential in remediating radioactive wastewater in terms of environmental friendliness and desirable bandgap as well as the availability of CdS, but is still limited by undesirable efficiency and stability from photogenerated carrier recombination and photocorrosion. Herein, we have elegantly designed tailor-made CdS@Prussian blue with homo/heterojunctions via one-pot kinetic regulation. The key to such a structure is to leverage the outstanding binding affinity between cyanogroups of Prussian blue and Cd2+ to create diversity of local precursor concentration differences. With such unique structure and rational energy band distribution, our photocatalysts demonstrate an unprecedented U(VI) removal efficiency as high as 2.5 times that of the pristine CdS. More importantly, the strong chelation between cyanogroups and Cd2+ endows our catalysts with extremely excellent stability compared with other state-of-the-art composite photocatalysts. This work provides a facile and universal inspiration for homo/heterojunction engineering of high-performance photocatalysts for photoreduction of uranium. [ABSTRACT FROM AUTHOR]

Electric-field driven uranium extraction from seawater has been proved to greatly enhance the performances of various adsorbents via gathering uranyl ions at the surfaces, but high-concentration interfering cations would also be enriched which generates shielding effects to reduce adsorption capacity. To address this issue, we have fabricated nanofiltration membranes with sieving-adsorption properties by choosing polyamidoxime (PAO) as substrates and polyamide as skin layers. On the one hand, the polyamide skin layers fabricated by interfacial polymerization could effectively separate uranyl ions from other metal ions according to the size-sieving effect since the size of uranyl ions is much larger than most interfering cations. The results demonstrated that the nanofiltration membranes could nearly 100 % reject uranyl ions while the rejections of other metal ions below 30 %. On the other hand, the rejected uranyl ions would be enriched at the surfaces of PAO substrates and followed by adsorption. The increased uranium concentrations are beneficial for both adsorption capacity as well as adsorption rate. Therefore, the adsorption capacity increased by 30 % compared with the pristine PAO adsorbents. This work not only provides a new strategy for the design of high-performance adsorbents, but also could promote the engineering process of uranium extraction from seawater which has an important scientific significance and application value. [Display omitted] • Nanofiltration membrane with sieving and adsorption properties is prepared. • Electric fields are beneficial for the gathering of uranium at membrane surfaces. • The NF membranes could separate uranium from interfering metal ions. • The adsorption capacity of NF membrane increased by 154 % compared with the pristine PAO adsorbent. [ABSTRACT FROM AUTHOR]

The development of sustainable bio-polyurethanes (bio-PU) from nonfood lignin has been attracting extensive attention owing to the abundant reserves, stable aromatic structures, and rich hydroxyls of lignin. However, exploiting a high-performance lignin-based PU integrating excellent mechanical properties with reprocessability is still a challenge. Herein, we proposed a dynamic phenolic-carbamates to construct robust and reprocessable bio-PU elastomers based on the reaction of phenolic lignin (PL) with isocyanate. Benefiting from the low M w of 1692 Da and the abundant phenolic hydroxyls of 8.3 mmol/g, the adaptable cross-linking network consisting of dynamic hydrogen bonds and phenolic-carbamates were formed by PL. The synthesized phenolic lignin-based PU (PLPU) displayed tunable mechanical properties via adjusting PL substitution amount. The tensile strength, modulus and toughness of PLPU reached 58.8 MPa, 1350.3 MPa, and 57 MJ/m3 when the substitution amount of PL was 70%, respectively. Importantly, the reversible cross-linking structure endowed PLPU with excellent multi-reprocessability. After 5 reprocessing cycles, the retention ratio of strength, breaking elongation, modulus and toughness was 87.6%, 58.9%, 218.1% and 63.3%, respectively, which were 1.6, 1.1, 3.5, 2.2 times higher than those of commercial lignin-based polyurethane (CLPU). Therefore, this work not only presents a robust and multi-reprocessable lignin-based PU elastomer with high substitution amount, but also provides a promising sustainable alternative to replace petroleum-based plastic. [Display omitted] • Obtaining high reactive phenolic lignin with high Ph-OH content of 8.3 mmol/g. • Building dynamic H-bonds and phenolic-carbamate bonds with phenolic lignin. • Reversible crosslinks endowed PLPU with excellent mechanical and thermoplastic properties. • Maintaining 87.6% of strength after 5 remodeling cycles. [ABSTRACT FROM AUTHOR]

Phase change materials (PCMs) were characterized to adsorb/release the thermal energy during the phase transition process over a certain temperature range. The PCMs had been incorporated into textiles to enhance the thermal property and the products are labeled as PCM textiles. The thermal behavior of the PCM textiles (the PCM fibers, the PCM yarns, and the PCM fabrics) was investigated for decades. The application of the PCM textiles was also extended to various fields. Based on the numerous research work, the publications related to the PCM textiles were already summarized. However, it was found that some reviews tended to describe the application of the microencapsulation PCMs, and some reviews focused on the fabrication of the PCM ultrafine fibers via electrospinning. In addition, there are some novel technologies to fabricate the PCMs, the novel methods to evaluate the PCM textiles, and the novel applications of the PCM textiles in recent years. In this review, the recent research work related to PCM textiles was summarized, which was aimed to deepen the understanding of the PCM textiles. [ABSTRACT FROM AUTHOR]

A new solid-state NMR experimental equipment was developed to monitor the structural change of polymer and protein fibers under active uniaxial deformation. The equipment was applied to monitoring change in the structure of a biodegradable aliphatic polyester fiber, poly(tetramethylene succinate) (PTMS; [–O(CH 2 ) 4 OCO–(CH 2 ) 2 CO–] n ), as a function of tensile stress. The crystal transition from α to β forms for PTMS was induced by stress and monitored by the change of the methylene region in the 13 C NMR spectra. The 13 C chemical shielding constant for the model compound of poly(tetramethylene succinate) was calculated using the GIAO–CHF (gauge invariant atomic orbitals–coupled Hartree–Fock) with ab initio 6-311G ∗∗ basis set. This calculation acceptably explains the experimental results. [ABSTRACT FROM AUTHOR]

Nowadays high porosity aerogels are widely applied in wastewater purification, while the fragility and unversatility of nascent cellulose aerogels limited the application in oil/water filtering separation. Here, highly compressible, elastic, superhydrophobic cellulose/poly(vinyl alcohol) (PVA) composite aerogels were fabricated via combination of chemical cross-linking, freeze drying and silanization. The obtained cellulose/PVA aerogels exhibited durable superhydrophobicity with WCA of 156.6 °, even maintaining 155.0 ° after 30 days. Synergistic effects of physical entanglement, chemical cross-linking and H-bond network between cellulose and PVA molecular chains endowed the aerogels with excellent compressibility and recoverability. The aerogels exhibited maximum compressive stress of 490.7 kPa at 90% strain, even without reduction in mechanical strength under 70% compressive strain for 10 cycles. More importantly, the strengthened aerogels exhibited remarkable separation performances for both immiscible oil/water mixtures and surfactant-stabilized water-in-oil emulsions. Fascinating permeation flux of up to 7176.3 L m−2 h−1 and total separation amount as high as 4550.6 L m−2 with separation efficiency of 98.5% for water-in-cyclohexane emulsion were harvested. Thus, this work provides a green, sustainable and mass-producible cellulose-based aerogel for high-efficiency oily wastewater remediation. [ABSTRACT FROM AUTHOR]

Green and sustainable cellulose aerogels have attracted extensive attention, but are severely limited by unsatisfied elasticity, fatigue resistance as well as fire hazard for functional applications. Herein, we proposed a novel and feasible strategy to fabricate highly elastic, thermal insulating and fireproof phytic acid/cellulose (PA/CE) aerogel via constructing microfilament substructure derived from PA-induced aggregation and assembly of cellulose chains. Benefiting from the interconnected fibrous cellular walls integrating with abundant microfilaments, the resultant PA/CE aerogels demonstrated excellent compressibility and resilience with recovery rate of 91.26% after 100 compressive cycles at 50% strain. With the hierarchical porous structure, PA/CE aerogels exhibited low thermal conductivity of 0.0340–0.0352 W/m·K, could maintain its structural integrity and high temperature thermal insulation after heat treatment for 30 min at 400 ℃. Moreover, the integration of PA enabled aerogel high fireproofing with limiting oxygen index (LOI) of 42.6% and UL-94 V-0 rating. The peak of heat release rate (PHRR) and total heat release (THR) of PA/CE aerogels were 79.97 kW/m2 and 1.75 MJ/m2, reduction by 43.0% and 46.5% compared with cellulose aerogels. Thus, the elastic cellulose aerogels proposed by this strategy provide an insight and feasibility for high performance and multifunctional applications. [Display omitted] • PA-induced aggregation and assembly of cellulose chains was proposed. • The resulting PA/CE aerogels had hierarchical porous structure with plentiful microfilament substructures. • The aerogels displayed excellent compressibility and fatigue resistance with recovery rate of 91.26% after 100 compressive cycles. • The aerogels possessed high temperature thermal insulation with structural integrity bearing heat treatment at 400 ℃ for 30 min. • The aerogels showed high fireproofing with 43.0% and 46.5% reduction of PHRR and THR compared with CE aerogels. [ABSTRACT FROM AUTHOR]

The properties of polyglycolide (PGA) fibers used as surgical sutures depend on their aggregated state structure. The study investigated the relationship between the structural evolution and macroscopic properties of PGA fibers with low-crystallinity under coupled stress-temperature fields by conducting in-situ WAXD/SAXS, DSC and SEM measurements. The WAXD and SAXS results indicated that the structural evolution during the low-temperature stretching stage primarily relied on stress-induced amorphous molecular chain orientation and the formation of small crystals. The DSC results confirmed that uniaxial stretching enhanced the orientation of amorphous molecular chains, leading to cold crystallization of PGA fibers at lower temperatures. During the heating stretching stage at temperatures of 60–90 °C, numerous crystals were generated through a lamellar insertion mechanism and underwent lateral growth. This is reflected by the crystallinity, crystal orientation, and crystallite sizes increased significantly, while the long period decreased rapidly. The high-temperature stretching stage resulted in fragmentation and recrystallization of lamellar crystals, forming fibrous crystals. Stretching at 110 °C exhibited higher Iq 2 /Iq 1 values than other temperatures, which means that 110 °C is more favorable for the formation of fibrous crystals. Additionally, PGA fibers stretched at 150 °C exhibited the highest crystallinity and crystal orientation, which led to a 440 % increase in tensile strength. Its resistance to degradation has also been significantly improved compared to the original fibers. [Display omitted] • Low-crystallinity PGA fibers were stretched during variable temperature. • The stress and temperature fields dominated the structural evolution in different stretching stages. • Hot stretching improved the mechanical properties and resistance to degradation of PGA fibers. [ABSTRACT FROM AUTHOR]

[Display omitted] • LZO-modified NCM811 is prepared via sol–gel coating and annealing methods. • Influence of annealing temperatures systematically studied. • The 750 °C annealed sample shows best electrochemical performances. • Optimized annealing procedure enhances microstructural stability and alleviates cation mixing. Li 2 ZrO 3 (LZO) coating has been routinely applied on Ni-rich NCM cathode materials via two-step processes to improve their electrochemical performances, but procedures for sample preparation remain elusive. Ni-rich NCM materials are particularly sensitive to temperatures, but annealing temperatures show random variation between 400 and 850 °C in literatures. In this work, the influence of annealing temperature on microstructures and electrochemical properties are systematically studied for the LZO-modified NCM811. It is found that, a thicker LZO coating with amorphous features can be obtained at a lower annealing temperature; but the LZO is fully dissolved into the crystal lattice of NCM811 at a higher temperature. The best electrochemical performance is achieved at the condition of 750 °C, because an optimized annealing temperature can introduce moderate Zr4+ doping and obtain high-quality coating layers. This work offers a guidance for industrial to enhance electrochemical performances of Ni-rich NCM cathode materials during surface modification processes. [ABSTRACT FROM AUTHOR]

Mechanically twisting a yarn is a useful and important method for creating internal stress, changing macromolecular orientation, and affording interesting fiber properties, including mechanical, structural, physical and chemical properties. Bacterial cellulose (BC) nanofibers are a new type of highly crystalline bionanofibers exhibiting excellent intrinsic mechanical properties. Herein, BC macrofibers with a diameter of 0.35–0.53 mm were prepared from BC hydrogel films using a two-step technique involving drying and twisting processes. Moreover, the effects of the drying method (oven- and freeze-drying) and those of the processing steps on the morphologies, structures, and physicochemical properties of the macrofibers were investigated. Results indicated that only the wet twisting–first process affords continuous macrofibers with a compact and uniform structure. The tensile strength and elongation at break of the macrofibers were 199 MPa and 24%, respectively. Furthermore, by introducing graphene oxide (GO) to the macrofibers, a photothermal and moisture actuator was facilely constructed, which could produce a twisting motion of 0.39 rpm and an untwisting motion of 0.6 rpm. This study provides insights into methods to easily alter the properties of BC macrofibers, which is pivotal for the macrofiber's potential application in intelligent devices. [Display omitted] • The surface of T-OD macrofibers is smooth and flat, and the tensile stress can reach 199 MPa. • The GO-T-OD macrofiber can produce reversible motion under moisture and NIR light stimulation, and the rotation angle can be increased to 121°/cm in 25 s • Reversible twisting artificial muscles offer unlimited possibilities for future applications in artificial muscles and other intelligent drives. [ABSTRACT FROM AUTHOR]

Fiber-based wearable electronic textiles have broad applications, but non-degradable substrates may contribute to electronic waste. The application of cellulose-based composite fibers as e-textiles is hindered by the lack of fast and effective preparation methods. Here, we fabricated polyaniline (PANI)/cellulose fibers (PC) with a unique skin-core structure through a wet-spinning homogeneous blended system. The conductive network formation was enabled at a mere 1 wt% PANI. Notably, PC15 (15 wt% PANI) shows higher electrical conductivity of 21.50 mS cm−1. Further, PC15 exhibits excellent ammonia sensing performance with a sensitivity of 2.49 %/ppm and a low limit of detection (LOD) of 0.6 ppm. Cellulose-based composite fibers in this work demonstrate good gas sensing and anti-static properties as potential devices for smart e-textiles. [Display omitted] [ABSTRACT FROM AUTHOR]

Many gel-like soft composites were obtained by using thermoplastic polyurethane (TPU) as the matrix in this work. Different contents of plasticizer dibutyl adipate (DBA) was added to TPU to swell its molecular chains and allowed them to pass through each other easily. These samples were then sandwiched between two electrodes as actuators and their actuation abilities were investigated. The results showed that the largest deflection among those samples was up to 12.11 mm, which corresponds to 48.44% of the length of samples (at 2.86 V μm−1). The deflection increased with increasing of the electric field intensity. Besides, the actuator was able to promptly respond to the change of voltage within 0.12 s. A wide response ability in the frequency region from 0.5 Hz to 10 Hz was confirmed, and the largest amplitude over 22 mm of the actuator was observed at 5 Hz. Furthermore, a new method was proposed in this paper to estimate the tiny force generated by the actuator. The small variation (less than 3%) of the measured results indicated that the proposed method is reliable even at a small bending angle. It is believed that the rapid bending capability and large deformation of the developed actuator at low intensity of electric field will make its considerable contributions to the field of soft robotics or biomaterials. Image 1 • Plasticized gel based actuators were prepared and their properties were investigated. • The largest actuating deflection was up to 48.44% of the sample length at 2.86 V μm−1 • The actuation behaviors in an electric field is a consequence of multiple factors. • A new method was proposed to estimate the tiny actuation force. [ABSTRACT FROM AUTHOR]

Double stimuli-responsive functionalized cellulose nanocrystal-poly[2-(dimethylamino)ethyl methacrylate] (CNC- g -PDMAEMA) reinforced poly(3-hydroxybutyrate- co -3-hydroxy valerate) (PHBV) electrospun composite membranes were explored as drug delivery vehicles using tetracycline hydrochloride (TH) as a model drug. It was found that rigid CNC- g -PDMAEMA nanoparticles enhanced thermal, crystallization and hydrophilic properties of PHBV. Moreover, great improvements in fiber diameter uniformity, crystallization ability and maximum decomposition temperature (T max) could be achieved at 6 wt% CNC- g -PDMAEMA. Furthermore, by introducing stimuli-responsive CNC- g -PDMAEMA nanofillers, intelligent and long-term sustained release behavior of composite membranes could be achieved. The releasing mechanism of composite membranes based on zero order, first order, Higuchi and Korsmeyere-Peppas mathematical models was clearly demonstrated, giving effective technical guidance for practical drug delivery systems. Electrospun PHBV composites membrane with double stimuli-responsive cellulose nanocrystal tailor drug release at human physiological condition for long-term sustained drug delivery. Unlabelled Image • Functionalized cellulose nanocrystals gave double stimuli-responsive performance. • Composite membrane has intelligent drug release ability at human physiological condition. • Composite membrane shows faster drug rate at pH = 5 for potential tumor cell targeting. • Four releasing mechanism of composite membranes have been clearly demonstrated. [ABSTRACT FROM AUTHOR]

• Novel fabrication of dipeptide and curcumin onto the silk protein hydrogel dressing. • Designed materials have promising cell compatibility and effective bacterial inhibition. • Metal chelating L-carnosine has greatly influencing the inactivation of MMP-9. • This hydrogel dressing could be accelerate therapeutic potential of diabetic wound healing. The infected diabetic wound ulcer is a significant problem for the diabetic patients, which leads to removal of affected foot site due to its delayed/non-healing tissues. The poly-microbial infections and active matrix metalloproteinases (MMP) are the significant influencing factors to delayed healing in diabetic mice. The main purposes of present investigation are to evaluation the targeted inactivation of MMP and avoid polymicrobial infections by using a combined therapeutic effect of metal chelating dipeptide (L-carnosine) and curcumin with the biocompatible silk protein hydrogel (L-car@cur/SF) dressing in the infected diabetic wound ulcer. The in vitro biological assay methods, such as, cell viability, anti-oxidant activity, anti-inflammatory macrophage cells and inhibition collagenase exhibited that the designed hydrogel matrix to be human cell compatible and could be accelerate for significant diabetic healing potential. The activation of cur/SF matrix by the L-carnosine was persuading the inactivation of matrix metalloproteinase-9 (MMP-9) through its potent chelating effects of Zn2+ ions from the MMP-9 active center. The L-car@cur/SF hydrogel was demonstrated for the effective MMP-9 inactivation and bacterial inhibition via in vivo mice wound site, which indorsed the diabetic wound healing efficiency in streptozotocin-tempted diabetic mice. [ABSTRACT FROM AUTHOR]

As an important class of natural resources, lignin and its utilization receive more and more attention. However, it is treated as waste in paper industry and causes serious pollution of natural water bodies. Meanwhile, the uncontrollable surface topography and the crystal form of natural calcium carbonate (CaCO3) severely restrict its application in the industrial field. Biomineralization may provide a perfect solution for these two issues. In this work, two types of specific crystal forms, cinnamic acid & aragonite crystal (CAAs) and cinnamic acid & vaterite crystal (CAVs) were directly synthesized in the presence of cinnamic acid. Two kinds of polymorph states were also found in the growth process of CaCO3. The structural properties of CAAs and CAVs as well as their polymorph states were characterized by FESEM, AFM, FTIR spectroscopy, XRD and TGA. The results showed that CAAs and CAVs held the crystal forms of aragonite and vaterite, respectively. The crystal forms of CaCO3 followed the growth rule that they dynamically changed from calcite to aragonite and then to vaterite. The formation mechanism is illustrated in the nucleation and crystal growth processes of CaCO3; cinnamic acid first formed various surfaces with the change in ambient conditions. These made CaCO3 to form different crystal forms and surface structures. [ABSTRACT FROM AUTHOR]

• Solvent free technology is applied in the polymerization of MEPCM. • The MEPCM possess high latent heat, good thermal stability and high thermal conductivity. • The mechanism of the interfacial polymerization is revealed by in situ component analysis. A kind of eco-friendly micro-encapsulated phase change materials (MEPCM) with dodecanol dodecanoate as core material were synthesized via the interfacial polymerization of toluene-2, 4-diisocyanate (TDI) and diethylenetriamine (DETA). During the preparation, a facile solvent free synthesis route was developed owing to the good compatibility of TDI and dodecanol dodecanoate. The synthesized MEPCM were characterized by Field Emission Scanning Electron Microscopy (FE-SEM), Particle Size Distribution (PSD) analyzer, Differential Scanning Calorimetry (DSC), Thermogravimetric/Infrared spectrometry (TG-IR) and thermal constants analyzer. It is found that the resultant MEPCM in nearly spherical shape are in the size scope from 10.0 to 40.0 μm, have the average latent heat in the range of 103.4–140.3 J/g, and exhibit high temperature resistance with an onset evaporation temperature at 234.0 °C. Moreover, the MEPCM possess good thermal conductivity from 0.17 W/m K to 0.21 W/m K. Therefore, it is confirmed that the prepared MEPCM can be regarded as a promising thermal energy storage material appropriate to the thermo-regulating fields such as renewable solar heating system. [ABSTRACT FROM AUTHOR]

Here, a novel Mg/Al-layered double oxide (MgAl-LDO) with a flower-like architecture was synthesized through facile green co-precipitation and calcination methods for phosphate separation and recycle from wastewater. The as-prepared MgAl-LDO demonstrated high specific surface area of 200.17 m2/g based on its 3D hierarchical flower-like structure. The phosphate adsorption was well conformed to Pseudo-second-order kinetic model and Langmuir model, suggesting a homogeneous monolayer chemisorption with a maximum adsorption capability of 103.61 mg P/g. The existence of Cl−, NO 3 − ions did not interfere with phosphate adsorption, while high concentration SO 4 2− and CO 3 2− affected the phosphate adsorption. In addition, adsorption mechanism analysis revealed that high-efficiency phosphate capture by MgAl-LDO was mainly due to the electrostatic adsorption, surface inner-sphere complexation, ligand exchange and precipitation combined process. Remarkably, the phosphate adsorbed MgAl-LDO (P-LDO) can be employed as synergistic flame retardant to improve the flame retardancy of paper. [ABSTRACT FROM AUTHOR]

Silk fibroin (SF) from Bombyx mori is a natural macromolecule with remarkable biocompatibility and adhesive ability. For wound healing bio-adhesive applications, good biodegradability is essential. The ideal bio-adhesive is expected to be fixed together in the early stage of wound healing, adhere to tissues to avoid cracking, and present slow and favorable degradation at the wound site after healing. The residual adhesive component should be completely degraded after the wound has healed either through being absorbed by the body or excreted through the biological metabolism. Herein, SF was functionalized with dopamine through a one-step method with crosslinkers to enhance its adhesive ability. Poly(ethylene glycol) (PEG) was selected to optimize the gelation time (NESFB-Dopa). The ratio of SF and PEG, the ratio of crosslinker, the amount of dopamine and the adhesive environment were tuned to determine the optimal conditions. Following the ASTM standard, when the weight ratio of SF to PEG was 5 : 5, the molar ratio of NHS to EDC was 2 : 1, and the content of dopamine was 5 weight%; also, the tensile strength of NESFB-Dopa achieved greater values of 460.44 ± 18.45 kPa and 503.32 ± 16.54 kPa in dry and wet conditions, respectively, which demonstrated superior adhesive properties compared with those of the clinically used fibrin sealants. [ABSTRACT FROM AUTHOR]

Blending of plant-based cellulose and marine-derived chitosan in micro-level has potential to make fascinating materials. However, this task is frequently hindered by the poor solubility of the polysaccharides. Here, using a green alkali/urea solvent media together with a well-designed dissolving strategy, original cellulose pulp and chitosan power were dispersed into a homogeneous solution. Driven by the intermolecular hydrogen-bond interaction, cellulose and chitosan chains were facially self-assembled into a unique 3D alloy structure. Owing to the rich interface interactions, the tensile strength and breaking elongation of the alloy film increased by 69% and 260%, respectively, when compared to a pure chitosan film. Besides, the 3D alloy films with a pore diameter of 920–1435 nm exhibited an extremely high cell viability which was higher than 95%. Additionally, accelerated wound healing rate of 95.6% reached in the presence of the alloy film after two weeks using a full-thickness wound in a rat model. Unlabelled Image • Chitosan and cellulose were co-dissolved into one green alkali/urea solvent. • Polysaccharide chains were self-assembled into 3D porous alloy films. • Abundant interface interactions led to excellent physicochemical properties. • Biocompatibility and bioactivity of the alloy result in good wound healing. [ABSTRACT FROM AUTHOR]

The preparation of noble metal‐free catalysts for water splitting is the key to low‐cost, sustainable hydrogen generation. Herein, through a pyrolysis‐oxidation process, we prepared a series of Co‐Fe‐Ni trimetallic oxidized carbon nanocubes (Co1‐XFeXNi‐OCNC) with a continuously changeable Co/Fe ratio (X=0, 0.1, 0.2, 0.5, 0.8, 0.9, 1). The Co1‐XFeXNi‐OCNC shows a volcano‐type oxygen evolution reaction (OER) activity. The optimized Co0.1Fe0.9Ni‐OCNC achieves a low overpotential of 268 mV at 10 mA cm−2 with a very low Tafel slope of 48 mV dec−1 in 1 m KOH. At the same time, the stability of the Co0.1Fe0.9Ni‐OCNC is also outstanding; after 1000 CV cycles, the LSV plot is almost coincident. Moreover, the potential remains almost of the same value at 10 mA cm−2 after 12 h in comparison to the initial value. The excellent electrocatalytic properties can be attributed to the synergistic cooperation between each component. Therefore, the Co0.1Fe0.9Ni‐OCNC is a promising candidate instead of precious metal‐based electrocatalysts for OER. [ABSTRACT FROM AUTHOR]

In this paper, novel hydrogen-bonded metal-complex frameworks MPM-1-TIFSIX and HOF-21 were selected as adsorbents to adsorb iodine. MPM-1-TIFSIX and HOF-21 were prepared by layering method and mixed stirring method, respectively. The structures of the two HOFs were characterized in detail by XRD, BET, TGA and FT-IR. The adsorption behavior and adsorption capacity of MPM-1-TIFSIX and HOF-21 for iodine were investigated in detail. The experimental data showed that the equilibrium adsorption amounts of MPM-1-TIFSIX and HOF-21 were 205.51 mg/g and 172.86 mg/g, respectively. The adsorption process of MPM-1-TIFSIX was conformed to be pseudo-second-order kinetic, while the adsorption process of HOF-21 was conformed to be pseudo-first-order kinetic. The results indicated that HOFs could be used as iodine capture and storage materials. Two different structures of HOF materials were synthesized and used for the capture of iodine. Both materials have different properties, which are related to their structure. MPM-1-TIFSIX with a larger pore size is capable of adsorbing more iodine molecules. HOF-21 can only absorb a small amount of iodine due to the small pores, which can also be seen from the figure. Image 1 [ABSTRACT FROM AUTHOR]

Nanostructured materials with designable microstructure fabricated through a facile and green method are highly desired for practical applications in nanotechnology. Herein, without using any toxic reagents, flexible cellulose aerogel nanocomposites embedded with ZnO@noble metal nanoparticles (NPs) were successfully prepared from a cellulose dope. Morphology, structure, and mechanical properties of the nanocomposite were characterized. Flower-liker ZnO particles were synthesized through cellulose mineralization and it acted as a platform for efficient photocatalytic synthesis of noble metal (Ag, Au, Ag-Au) NPs. The noble metal NPs were well dispersed in the three-dimensional (3D) cellulose skeleton, resulting in abundant "hot spots" for high Surface Enhanced Raman Scattering (SERS) signal enhancement. Using rhodamine 6 G (R6G) molecules as probe molecules, the detection limits and calculated enhancement factors approached to 10−10 M and 4.8 × 107, respectively. Particularly, the photocatalytic capabilities of noble metal-semiconductor heterostructure embedded in porous aerogel made it a self-cleaned SERS substrate. There was little sensitivity loss after recycling use for 3 times. This work presented a sustainable and cost-reduction strategy to construct sensitive SERS substrate. [Display omitted] • Cellulose aerogel embedded with ZnO@Ag/Au is facilely fabricated from a dope. • The actived celluloe chains act as mineralization template for flower-like ZnO. • Ag/Au NPs are plated to ZnO surface through a controllable photoreduction method. • 3D porous aerogel gives anchoring effect for particles and bring abundant "hot spots". • Hierarchical nanostructures achieves a flexible, sensitive and reusable SERS strips. [ABSTRACT FROM AUTHOR]

BiOCl as a two‐dimensional layer ternary oxide semiconductor, has been widely used in energy and environmental area due to its non‐toxicity, price and the good photocatalytic performance. However, BiOCl has a wide bandgap and can only absorb ultraviolet light, which limits its solar energy conversion efficiency for practical application. Herein, we report a facile synthesis of FeOOH/BiOCl nanocomposites by hydrothermal method. The results of XPS and FT‐IR indicated that FeOOH has been loaded on the nanocomposites. The chemical and optical properties of the nanocomposite are well‐characterized. The nanocomposite showed much more excellent photocatalytic performance compared with the individual FeOOH and BiOCl single component. Reactive specie trapping experiment indicated that·O2– and h+ were the two main active species during the photocatalytic process of FeOOH/BiOCl nanocomposites. [ABSTRACT FROM AUTHOR]

ZIF-67@Yeast was synthesized with in-situ growth procedure by using hydrothermally carbonized yeast as the substrate material. The prepared ZIF-67@Yeast was characterized in detail by SEM, BET, XRD and TG analysis. In addition, the adsorption properties of Pb2+ by ZIF-67@Yeast were also investigated. The results show that the adsorption capacity of Pb2+ by ZIF-67@Yeast is larger than the sum of the adsorption capacity of Pb2+ by individual yeast and ZIF-67. Yeast could maintain a stable morphology after hydrothermal carbonization at 180 °C. Therefore, many MOFs synthesized by hydrothermal or microwave methods at 180 °C could also be compounded with Yeast as a base material. This provides more possibilities that heavy metal ions are adsorbed by the synthesis of more diverse MOFs composites. ZIF-67@Yeast was synthesized by in situ growth using a hydrothermally carbonized yeast as a substrate material, which can maintain a stable morphology and efficient removal of Pb2+ in water. Image 1 • ZIF-67@Yeast was synthesized by using a hydrothermally carbonized yeast as a substrate material. • The adsorption capacity of Pb2+ by ZIF-67@Yeast is larger than that of Pb2+ by individual yeast and ZIF-67. • Many MOFs could also be compounded with yeast as a base material. [ABSTRACT FROM AUTHOR]

Non‐noble metal‐based metal–organic framework (MOF)‐derived electrocatalysts have recently attracted great interest in the oxygen evolution reaction (OER). Here we report a facile synthesis of nickel‐based bimetallic electrocatalysts derived from 2D nanosheet‐assembled nanoflower‐like MOFs. The optimized morphologies and large Brunauer–Emmett–Teller (BET) surface area endow FeNi@CNF with efficient OER performance, where the aligned nanosheets can expose abundant active sites and benefit electron transfer. The complex nanoflower morphologies together with the synergistic effects between two metals attributed to the OER activity of the Ni‐based bimetallic catalysts. The optimized FeNi@CNF afforded an overpotential of 356 mV at a current density of 10 mA cm−2 with a Tafel slope of 62.6 mV dec−1, and also exhibited superior durability with only slightly degradation after 24 hours of continuous operation. The results may inspire the use of complex nanosheet‐assembled nanostructures to explore highly active catalysts for various applications. [ABSTRACT FROM AUTHOR]

Abstract Metal-organic frameworks (MOFs) benefitting from its controllable and diverse structure are a class of promising materials for diverse field. However, its directly employed for oxygen evolution reaction (OER) is still rare. Particularly, two-dimensional (2D) MOF nanosheets materials possess both advantages of 2D layered nanomaterials and MOFs, are considered as promising nanomaterials. Herein, we report a facile and scalable in situ hydrothermal synthesis of a 2D Co-based bimetallic MOFs (Co-Fe/Ni@HPA-MOF nanosheets), which can be stable in alkaline solution and directly adopted as highly efficient electrocatalysts. The Co-Ni@HPA-MOF can reach a current density of 10 mA cm−2 at low overpotential of 320 mV with a small Tafel slope of 58 mV dec−1, which is comparable to that of commercial RuO 2 (58 mV dec−1). The excellent electrocatalytic properties can be attributed to the 2D nanosheet and the coupling effect between Co and Ni, which provided large number of accessible active sites. The results highlight the great potential of utilizing MOF nanosheets for electrocatalysis, and will pave a way to develop more efficient 2D MOFs for diverse catalytic applications. Graphical abstract A facile and scalable in situ hydrothermal synthesis of a two dimensional Co-based bimetallic MOFs (Co-Fe/Ni@HPA-MOF nanosheets) was reported, which can be stable in alkaline solution and directly adopted as highly efficient electrocatalysts. fx1 Highlights • Two dimensional (2D) Co-based bimetallic metal-organic frameworks (MOFs) nanosheets were fabricated. • The Co-Ni@HPA-MOF nanosheet can reach a current density of 10 mA cm−2 at low overpotential of 320 mV. • The excellent electrocatalytic properties can be attributed to the coupling effect between Co and Ni. [ABSTRACT FROM AUTHOR]

To improve the roles of tumor drug, porous silk fibroin particles have been designed as drug carriers. Doxorubicin (DOX) is encapsulated during the fabrication process of the silk fibroin particles to form DOX loaded silk fibroin particles (SFPs-DOX). Folic acid (FA) is covalently grafted to the surface of the silk fibroin particles (FA-SFPs-DOX) as a target group to the folate receptor of tumor cells. The experimental results showed that under the conditions of low pH, high ionic strength and high enzyme concentration, the release of loaded drugs in particles has stimulus response under various conditions. The synthesized silk fibroin particles have good biocompatibility. The specific binding of fibroin particles to folate receptors provides the particles to with target functions to the tumor cells. The job develops potential application of silk fibroin particles as smart drug carriers for the targeted therapy of tumor. [ABSTRACT FROM AUTHOR]

Highlights • A facile method of loading metal-organic frameworks (MOFs) onto cellulose aerogels (CA) is developed. • The equilibrium adsorption capacity of Pb2+ adsorbed by UiO-66-NH 2 @CA was 89.40 mg g−1. • The complete decomposition temperature of UiO-66-NH 2 @CA was increased by 62.1 ℃ compared with CA. • The hybrid aerogels could be recycled without secondary pollution. Abstract In the present work, we develop novel method of loading metal-organic frameworks (UiO-66 and UiO-66-NH 2) on the flexible cellulose aerogels as metal-organic frameworks@cellulose aerogels composite materials by using in situ growth procedure at room temperature. The as prepared metal-organic frameworks@cellulose aerogels composite materials were well characterized via SEM, XRD, atomic absorption spectrometer, and TG analysis, besides the adsorption of Pb2+ and Cu2+ in metal-organic frameworks@cellulose aerogels composite materials was investigated. The amount of metal ions adsorbed by metal-organic frameworks@cellulose aerogels composite materials is equal to the sum of metal-organic frameworks and cellulose aerogels, indicating that the metal-organic frameworks are not blocked after cellulose aerogels growth and still have adsorption properties. It was found that metal-organic frameworks@cellulose aerogels composite materials can be recycled to adsorb Pb2+ and Cu2+ in water after simple cleaning. The equilibrium adsorption capacity of Pb2+ adsorbed by UiO-66-NH 2 @CA was 89.40 mg g−1, and can be easily reused for more than 5 cycles without significant decrease in performance. Moreover, the maximum decomposition temperature (T max) of UiO-66-NH 2 @CA was increased by 62.1℃. This result suggested that such metal-organic frameworks@cellulose aerogels composite materials could adsorb heavy metal ions in water could by avoiding secondary pollution and show great potential in water treatment. [ABSTRACT FROM AUTHOR]

Nowadays, there still exists big challenges to synthesize active and inexpensive electrocatalysts for oxygen evolution reaction. In this work, we propose a new method by using melamine‐uric acid (MAUA) supramolecular nanofibers as precursor to fabricate metal‐embedded nitrogen‐doped carbon nanotube materials (MM′@NCNTs, M, M′ = Fe, Co, Ni). The samples exhibit superior and stable catalytic performance for oxygen evolution reaction (OER) in alkaline medium. In all the electrocatalysts, FeNi@NCNT shows the best electrocatalytic activity with the overpotential is only 402 mV (vs. RHE) at 10 mA·cm–2, which shows better performance than both Fe@NCNT and Ni@NCNT. The smaller Tafel slope value, with the value of 68 mV·dec–1, indicates the superior OER activity of FeNi@NCNT. These results reveal a synergistic effect between Fe, Co, and Ni, which could produce a favorable coordination environment that enhance the activity for oxygen evolution reaction. [ABSTRACT FROM AUTHOR]

Cellulose based Ag-functionalized ZnO nanocomposite (AZC) films were prepared using a green and easy scale-up strategy. Firstly, ZnO embedded cellulose (ZC) nanocomposite was synthesized from a cellulose-NaOH/zincate/urea solution through a biomimetic approach. Secondly, Ag nanoparticles (NPs) with a mean diameter of 53.2 nm were efficiently deposited onto the surface of embedded ZnO in cellulose matrix under UV irradiation (16 w), yielding the multi-hybrid AZC film. Owing to the porous structure of cellulose substrate and its rich hydroxyl group, the NPs in the ACZ films displayed good stability. Because of the formation of Schottky barriers in the Ag-ZnO regions, the catalytic activity of ACZ films increased by 20 times when compared to that of ZC sample. Furthermore, the AZC films could completely inhibit both S. aureus and E. coli growth. This facile and eco-friendly approach is expected to pave the way for constructing multifunctional cellulose material for various niche applications. [ABSTRACT FROM AUTHOR]

Hydrogen production is one of the most effective methods for combating the global energy crisis. However, improving the electrochemical performance of oxygen‐evolution catalysts is a significant challenge. In this paper, exceptionally active electrocatalysts for oxygen‐evolution reactions (OERs) were successfully developed and characterized by using SEM, TEM, XRD, BET, and X‐ray photoelectron spectroscopy. The nitrogen‐doped hollow‐carbon‐encapsulated bimetallic nanoparticles (MM′‐NHCNPs) were prepared by using folic acid coordination polymerization. The hollow structure and the synergistic effect of bimetallic doping exhibited remarkable catalytic performance and outstanding stability for the OER in a 1.0 m KOH alkaline electrolyte. For the OER, the overpotential of the best catalyst was only 350 mV at a current density of 10 mA cm−2 with a small Tafel slope of 58 mV dec−1. High durability was also demonstrated by the MM′‐NHCNPs. Such an MM′‐NHCNP catalyst with excellent electrochemical properties provides a promising material for OERs. It′s a wrap! Bimetallic nitrogen‐doped hollow‐carbon‐wrapped nanoparticles (MM′‐NHCNPs) were prepared by using folic acid coordination polymerization. Such an MM′‐NHCNP catalyst with excellent electrochemical properties provides a promising material for oxygen‐evolution reactions (see figure). [ABSTRACT FROM AUTHOR]

A novel chemical reduction method was reported to prepare tunable spherical or belted morphologies of nano-selenium (Se) based on cellulose nanocrystal (CNC). The homogeneous Se nanospheres with size of about 36 nm can be found for Se-Sphere-12H by adding ascorbic acid (VC) as assisted reducing agent. The Se nanobelt with a length of about 800 nm can be observed for Se-Belt-12H through one-pot reaction of CNC with sodium selenite (Na 2 SeO 3 ) under hydrothermal conditions. Moreover, Se-Belt-12H exhibited the higher crystallinity of 96.10% and maximum thermal degradation temperature (T max ) of 479.4 °C, the highest capacitance and the smallest internal resistance. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) as catalysts for the activation of peroxymonosulfate (PMS) to remove recalcitrant organic contaminants has been well reported, however, the separation of MOFs from the solution is difficult because of their powder state, which limits their applications. In the present study, zeolitic imidazole framework (ZIF) materials, ZIF-9 and ZIF-12 were pioneered to load on cellulose aerogels, and the hybrid aerogels as metal catalysts to effectively activate PMS for Rhodamine B (RB), tetracycline hydrochloride (TC) and p-nitrophenol (PNP) degradation. The hybrid aerogels/PMS system could remove PNP about 90% in 1 h, which hard to remove from water. The pH value of the solution had no effect on the degradation process, which demonstrated that the hybrid aerogels had excellent pH tolerance. In addition, the mechanism of PNP degradation was investigated by electron paramagnetic resonance (EPR) and free radical trapping methods. The results showed that PMS could effectively activate by hybrid aerogels to produce sulfate radicals (SO 4 −), hydroxyl radicals ( OH), and revealed that SO 4 − play a key role in degradation. The most important feature of hybrid aerogels is can be easily separated from the solution. The obtained results showed that the hybrid aerogels exhibit excellent recyclability, with no significant effect on degradation. The prepared hybrid aerogels are green, environmentally friendly with high catalytic efficiency. Further, the outstanding degradation of PNP demonstrates the promising prospects of hybrid aerogels as advanced oxidation process (AOP) catalysts. [ABSTRACT FROM AUTHOR]

A facile method is reported to form a honeycomb‐like porous nanomaterial by intercalation of iron nitrate using nature silk sericin (SS) as nitrogen and carbon source. A series of Fe2O3 nanoparticles anchored on Fe2O3‐N‐doped graphite carbon electrocatalysts (SS‐Fe) were synthesized, exhibits well‐defined pore structure and excellent oxygen evolution reaction (OER) catalytic activities. Among these materials, SS‐Fe‐0.5 shows the best performance, the overpotential of SS‐Fe‐0.5 at 10 mA·cm–2 is 440 mV (vs. RHE) and the Tafel slope is only 68 mV·dec–1. The results indicate that it is promising to the preparation of carbon catalyst materials using natural, renewable and abundant resources for electrocatalysis. [ABSTRACT FROM AUTHOR]