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Conventional methods faced challenges in pretreating natural cellulose fibres due to their high energy consumption and large wastewater drainage. This research devised an efficient solid-state pretreatment method for pretreating hemp fibres using ethanolamine (ETA) assisted by microwave (MW) heating. This method produced a notable removal rate of lignin (85.4 %) with the highest cellulose content (83.0 %) at a high solid content (30 %) and low temperature (70 °C). Both FT-IR and XRD analyses indicated that the pretreatment did not alter the structure of cellulose within the hemp fibres but increased crystallinity as the CrI increased from 84 % in raw hemp fibre to 89 % in pretreated fibre. As a result, it produced hemp fibres with impressive fineness (4.6 dtex) and breaking strength (3.81 cN/dtex), meeting the requirement of textile fibre. In addition, an improvement in glucose concentration (15.6 %) was observed in enzymatic hydrolysis of the MW pretreated hemp fibres compared to the fibres pretreated without MW. Furthermore, the FT-IR and NMR data confirmed that the amination of lignin occurred even at low temperature, which contributed to the high lignin removal rate. Thus, this study presents a potentially effective energy-saving, and environmentally sustainable solid-state method for pretreating hemp fibres., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

The traditional textile degumming process produces abundant wastewater, which contains a lot of monosaccharides and oligosaccharides. It is of great economic and environmental significance to utilize these carbohydrates in high value. In this study, high performance liquid chromatography (HPLC) was used to analyze the carbohydrate components in kenaf degumming wastewater, and then the production of C-dots using the wastewater was explored. The results showed that the types and content in the degumming wastewater were monosaccharides (glucose, xylose and arabinose) and oligosaccharides (dextran, xylan and araban). The carbohydrate (mainly glucan and xylan) content in wastewater accounted for 91.16 % of the total carbohydrates weight loss in kenaf degumming process. By using hydrolysis and hydrothermal reaction on kenaf degumming wastewater, blue-green carbon dots (C-dots) with good performance were prepared and successfully applied to anti-counterfeiting printing. In particular, the as-prepared C-dots prepared from kenaf degumming wastewater with urea added (WUC-dots) showed an excitation-dependent photoluminescence (PL) spectrum and quantum yield (QY) of 2.4 % in aqueous solution. The fluorescent code exhibited a clear outline, excitation-tunable color and good stability, showing a great potential for anti-counterfeiting system., Competing Interests: Declaration of competing interest There are no conflicts to declare., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The catalytic conversion of cellulose to lactic acid (LA) has garnered significant attention in recent years due to the potential of cellulose as a renewable and sustainable biomass feedstock. Here, a series of Au/W-ZnO catalysts were synthesized and employed to transform cellulose into LA. Through the optimization of reaction parameters and catalyst compositions, we achieved complete cellulose conversion with a selectivity of 54.6% toward LA over Au/W-ZnO at 245 °C for 4 h. This catalyst system also proved effective at converting cotton and kenaf fibers. Structural and chemical characterizations revealed that the synergistic effect of W, ZnO, and Au facilitated mesoporous architecture generation and the establishment of an adequate acidic environment. The catalytic process proceeded through the hydrolysis of cellulose to glucose, isomerization to fructose, and its subsequent conversion to LA, with glucose isomerization identified as the rate-limiting step. These findings provide valuable insights for developing high-performance catalytic systems to convert cellulose.

The utilization of Cu-based catalysts in CO 2 conversion into valuable chemicals is of significant interest due to their potential in mitigating greenhouse gas emissions. However, the controllable design of Cu-based catalysts and the regulation of their mechanism remain challenging. In this study, a series of efficient Cu/L catalysts were prepared for this process, and the intrinsic influencing factors on the reaction routes were systematically revealed. Various techniques revealed that Cu particles in L-supported catalysts exhibited higher dispersion and formed Cu-O(OH)-K interfacial sites. However, with increasing Cu loading, the dispersion of Cu particles and the percentage of Cu-O(OH)-K interfaces decreased. Kinetic investigations revealed that the adsorption configuration and electronic structure of Cu species codetermined the reaction pathways and resulting selectivity. Cu/L catalysts possessing Cu-O(OH)-K interfaces and small particles demonstrated the preferential formation of formate species, promoting methanol formation. However, larger Cu particles generated carboxylate intermediates, resulting in higher CO selectivity..

The development of high-efficiency non-precious metal electrocatalysts for alkaline electrolyte hydrogen evolution reactions (HER) is of great significance in energy conversion to overcome the limited supply of fossil fuels and carbon emission. Here, a highly active electrocatalyst is presented for hydrogen production, consisting of 2D CoSe 2 /Co 3 S 4 heterostructured nanosheets along Co 3 O 4 nanofibers. The different reaction rate between the ion exchange reaction and redox reaction leads to the heterogeneous volume swelling, promoting the growth of 2D structure. The 2D/1D heteronanostructures enable the improved the electrochemical active area, the number of active sites, and more favorable H binding energy compared to individual cobalt chalcogenides. The roles of the different composition of the heterojunction are investigated, and the electrocatalysts based on the CoSe 2 /Co 3 S 4 @Co 3 O 4 exhibited an overpotential as low as 165 mV for 10 mA cm -2 and 393 mV for 200 mA cm -2 in 1 m KOH electrolyte. The as-prepared electrocatalysts remained active after 55 h operation without any significant decrease, indicating the excellent long-term operation stability of the electrode. The Faradaic efficiency of hydrogen production is close to 100% at different voltages. This work provides a new design strategy toward Co-based catalysts for efficient alkaline HER., (© 2023 Wiley-VCH GmbH.)

Discarded oil-containing absorbents, which has been used in handling oil spills, are tricky to deal with and have rose global environmental concerns regarding release of microplastics. Herein, we developed a facile strategy to fabricate sustainable absorbents by a gas-inflating method, through which 2D electrospinning polycaprolactone nanofiber membranes were directly inflated into highly porous 3D nanofiber/sheet aerogels with layered long fiber structure. The membranes were inflated rapidly from a baseline porosity of 81.98% into 97.36-99.42% in 10-60 min. The obtained aerogels were further wrapped with -CH 3 ended siloxane structures using CH 3 SiCl 3 . This hydrophobic absorbent (CA ≈ 145°) could rapidly trap oils from water with sorption range of 25.60-42.13 g/g and be recycled by simple squeeze due to its mechanical robustness. As-prepared aerogels also showed high separation efficiency to separate oils from both oil/water mixtures and oil-in-water emulsions (>96.4%). Interestingly, the oil-loaded absorbent after cleaning with absolute ethanol could be re-dissolved in selected solvents and promptly reconstituted by re-electrospinning and gas-inflation. The reconstituted aerogels were used as fire-new oil absorbents for repeated life cycles. The novel design, low cost and sustainability of the absorbent provides an efficient and environmentally-friendly solution for handling oil spills., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Water pollution, which is caused by leakage of oily substances, has been recognized as one of the most serious global environmental pollutions endangering the ecosystem. High-quality porous materials with superwettability, which are typically constructed in the form of aerogels, hold huge potential in the field of adsorption and removal of oily substances form water. Herein, we developed a facile strategy to fabricate a novel biomass absorbent with a layered tubular/sheet structure for efficient oil/water separation. The aerogels were fabricated by assembling hollow poplar catkin fiber into chitosan sheets using a directional freeze-drying method. The obtained aerogels were further wrapped with -CH 3 -ended siloxane structures using CH 3 SiCl 3 . This superhydrophobic aerogel (CA ≈ 154 ± 0.4°) could rapidly trap and remove oils from water with a large sorption range of 33.06-73.22 g/g. The aerogel facilitated stable oil recovery (90.07-92.34%) by squeezing after 10 sorption-desorption cycles because of its mechanical robustness (91.76% strain remaining after 50 compress-release cycles). The novel design, low cost, and sustainability of the aerogel provide an efficient and environmentally friendly solution for handling oil spills.

Developing ceramic nanofibrous membranes for the thermal insulation layer of firefighting protective clothing is vital. However, previous ceramic nanofibrous membranes were brittle and easy to break during service in high-temperature environments. The lack of elastic and compressible properties has limited the high-end applications of ceramic nanofibrous membranes. In this work, elastic and compressible Al 2 O 3 /ZrO 2 /La 2 O 3 nanofibrous membranes were fabricated via sol-gel electrospinning and calcination in air at different temperatures. The as-fabricated Al 2 O 3 /ZrO 2 /La 2 O 3 nanofibrous membranes can maintain excellent elasticity and compressibility in the temperature ranging from -196 to 1400 °C. Moreover, they have low thermal conductivity and high working temperatures. These favorable characteristics make the Al 2 O 3 /ZrO 2 /La 2 O 3 nanofibrous membranes a promising candidate for the thermal insulation layer of firefighting protective clothing., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The performance and effects of 12 different structures of stents in the bile duct were compared and used the finite element method. Numerical models of the 12 kinds of fluid-structure interaction(FSI) coupling systems were established to investigate the relationship between three aspects (velocity distribution of bile, wall shear stress (WSS) distribution of bile, and Von Mises Stress(VMS) distribution on the stent and bile duct) and the structural parameters of the stent (monofilament diameter and the number of braiding heads). After calculating and analyzing the simulation results yielding distributions of velocity, WWS, and VMS and regions of bile duct susceptibility to stenosis, they were consistent with previous findings on the locations of restenosis occurring after stent removal, indicating that the simulation results could provide a useful reference for studying biliary stents. The results of the simulations showed that (i) eddy currents were prone to occur at the stent ends regions; (ii) the WSS distribution of the bile fluid in contact with the stent and bile duct related to the stent structure; (iii) the high VMS on the stent and bile duct was prone to occur at the stent ends. The simulation results of 12 FSI coupling systems were studied and two superior stent model structures were obtained by comprehensive evaluation., Competing Interests: Declaration of Competing Interest There is no conflict of interest of any kind., (Copyright © 2023. Published by Elsevier Ltd.)

Rapid and effective removal of highly viscous oil spills from the sea remains a great challenge globally. Superhydrophobic materials are attractive candidates for handling oil spills, but they are restrained to recover oils with low viscosity exclusively. Herein, we report a novel polypyrrole wrapped superhydrophobic fibrous network using cross-shaped polyester fibers as starting blocks. The polypyrrole coating enables the absorbent to convert light to heat, ensuring that the viscosity of heavy oils in the proximity can be easily controlled. In the meanwhile, the special structure of the starting fibers initiates Concus Finn (CFin) capillary allowing instant oil transport in the network. When the absorbent is exposed to light oils (0-500 mPa.s), the oils can be transported instantly via CFin capillary. Interestingly, under synergistic effect of light-to-heat conversion and CFin capillary, a drawing-sticking crude oil strip (10 5 mPa.s) is sucked instantly against gravity by the absorbent. The absorbent is successfully applied to efficiently separate both oil/water mixtures and oil/water emulsions (efficiency > 99%). Such absorbent can absorb 62.99-74.23 g/g light oils on average and up to 123.3 g/g crude oil under 0-2 sun illumination, holding a huge potential in managing oil spills., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Air pollution induced by pathogenic particulate matter (PM) has posed a serious threat to public health worldwide. Advanced air filters are thus required, not only exhibiting high PM capture efficiency, low breathing resistance, and high internal moisture transferring performance but also isolating and inactivating external pathogenic aerosols. In this study, we demonstrated a facile approach to construct a biomimetic fibrous leaf-vein membrane with unidirectional water penetration and effective antibacterial PM filtration by one-step electrospinning of poly(vinylidene fluoride) (PVDF)-based multilayer nanofibers. With ultrathin fibers penetrating the skeletal framework of bimodal thick fibers, the membranes showed gradient interconnected porous structures and achieved a highly efficient and stable (in an acid and alkali environment) PM 0.3 interception (>99.98%) with low air drag (51-71 Pa). In addition, the gradient narrow pores of the membranes contributed to a gradient higher hydrophilicity. The subsequent unidirectional water motion effectively isolates pathogenic aerosols typically generated by external individuals or ultrafast water penetration from the inverse face. Moreover, the membranes demonstrated an antibacterial efficacy (>99.99%) in a 5 min contact, inactivating the intercepted airborne pathogens efficiently. The test results proved that the proposed membranes were promising advanced air filters for respirator applications.

Large scale solar-driven hydrogen production is a crucial step toward decarbonizing society. However, the solar-to-hydrogen (STH) conversion efficiency, long-term stability, and cost-effectiveness in hydrogen evolution reaction (HER) still need to be improved. Herein, an efficient approach is demonstrated to produce low-dimensional Pt/graphene-carbon nanofibers (CNFs)-based heterostructures for bias-free, highly efficient, and durable HER. Carbon dots are used as efficient building blocks for the in situ formation of graphene along the CNFs surface. The presence of graphene enhances the electronic conductivity of CNFs to ≈3013.5 S m -1  and simultaneously supports the uniform Pt clusters growth and efficient electron transport during HER. The electrode with a low Pt loading amount (3.4 µg cm -2 ) exhibits a remarkable mass activity of HER in both acidic and alkaline media, which is significantly better than that of commercial Pt/C (31 µg cm -2  of Pt loading). In addition, using a luminescent solar concentrator-coupled solar cell to provide voltage, the bias-free water splitting system exhibits an STH efficiency of 0.22% upon one-sun illumination. These results are promising toward using low-dimensional heterostructured catalysts for future energy storage and conversion applications., (© 2022 Wiley-VCH GmbH.)

Using tubular kapok fibers (KF) and sodium alginate (SA) as the natural building block, we put forward a novel oriented neurovascular network-like superhydrophobic aerogel with robust dry and wet compression resilience by directional freeze-drying and chemical vapor deposition. In the block, SA forms aligned channel structures providing space for rapid oil transmission, while KF serves as vascular-like capillaries acting as instant "tentacle" to capture the tiny oil droplets in water, facilitating fascinating oil capture efficiency for versatile oil/water separation, The aerogel after dry and wet compression (under a strain of 60%) can recover 96.0% and 97.3% its original, respectively, facilitating stable oil recovery (81.1-89.8%) by squeezing, high separation efficiency (99.04-99.64%) and permeation flux separating oil contaminants from water. A pump-supported experiment shows the aerogel efficiently collecting oil contaminants from the water's surface and bottom by 11503-25611 L·m -2 ·h -1 . Particularly, the aerogel as robust oil droplets captor facilely achieves isolation of 99.39-99.68% emulsified oils from oil/water emulsions by novel oil trapping mechanism which simply involves exerting kinetic energy on emulsified oils through repeated oscillation, potentially indicating a simple and efficient alternative to membrane-based oily wastewater remediation via filtration., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Environmentally friendly face masks with high filtration efficiency are in urgent need to fight against the COVID-19 pandemic, as well as other airborne viruses, bacteria and particulate matters. In this study, coaxial electrospinning was employed to fabricate a lithium chloride enhanced cellulose acetate/thermoplastic polyurethanes (CA/TPU-LiCl) face mask nanofiber filtration membrane, which was biodegradable and reusable. The analysis results show that the CA/TPU-LiCl membrane had an excellent filtration performance: when the filtration efficiency reached 99.8%, the pressure drop was only 52 Pa. The membrane also had an outstanding reusability. The filtration performance maintained at 98.2% after 10 test cycles, and an alcohol immersion disinfection treatment showed no effect on its filtration performance. In summary, the CA/TPU-LiCl nanofiber membrane made in this work is a promising biodegradable and reusable filtration material with a wide range of potential applications, including high-performance face mask.

Chemically deuterated cellulose fiber was expected to provide novel applications due to its spectral, biological, and kinetic isotope effect. In this research, the performance of the chemically deuterated cotton fibers, including their mechanical property, enzymatic degradation performance, effect on bacterial treatment, and fast identification (near-infrared modeling) was investigated. The breaking tenacity of the deuterated cotton fibers was slightly lower, which might be attributed to the structural damage during the chemical deuteration. The glucose yield by enzymatic hydrolysis was less than that of the protonic cotton fibers, implying the deuterated fibers are less sensitive to enzymatic degradation. Furthermore, the deuterated fibers could promote the growth of bacteria such as Escherichia. coli , which was associated with the released low-level deuterium content. At last, the near-infrared technique combined with partial least squares regression successfully achieved a fast identification of the protiated and deuterated cotton fibers, which significantly promoted the potential application of deuterated cellulose as anticounterfeiting materials (e.g., special paper)., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The handling editor declared a past collaboration with the author AR., (Copyright © 2021 Song, Liu, Ben, Zhang, Han, Ragauskas and Jiang.)

Developing functional materials integrating multi-tasking oil/water separation performances is significant but challenging for the remediation of large-scale oil spills causing pernicious environmental damages. Herein, a novel Concus Finn Capillary driven oil sorbent (OSCPF) fabricated by aligning superhydrophobic cruciate polyester fibers based on yarn spinning mechanism is designed to realize the clean-up of oil spills and various oil/water mixtures at high speeds. Instantaneous oil diffusion is achieved by abrupt Concus Finn Capillary driven oil-flows along aligned channels. This advance reduces the penetrating time for viscous crude oils by 95.00% comparing with that of non-oriented circular polyester fibers. The OSCPF possess great oil sorption capacity of 54.36-124.71 g/g and can separate oils from immiscible oil/water mixtures, including seawater, soap-water, CuCl 2 -water, and KMnO 4 -water, and surfactant-stabilized O/W emulsions by the way of adsorption with satisfactory separation efficiency (99.41-99.83%). Especially, the OSCPF is effectively used to enclose oil spills to prevent rapid oil diffusion and in-situ continuously collect the spillages from water surface and underwater by pumping device with recovery rates of 15,727-104,227 L·m -2 ·h -1 . Considering the unique structural design, fast oil sorption speed, and low operating cost, this work provides a prospective oil remover addressing the remediation of catastrophic multi-tasking oil/water pollutions., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Colloidal carbon quantum dots (C-dots) have attracted a lot of attention because of their excellent optical properties for various types of applications. Due to the complicated structure of C-dots, the photoluminescence (PL) mechanism of C-dots is still unclear. In particular, it is still a big challenge to understand well the surface chemistry of C-dots. In this work, we used a vacuum-heating approach to produce high-quality C-dots. With different purification procedures, the surface chemistry of C-dots can be well-controlled. Removal of Ca 2+ by Na 2 CO 3 led to the disappearance of the absorption at 405 nm and a decrease of the quantum yield. In addition, the Na 2 CO 3 treated C-dots exhibited an excitation-dependent PL behavior. These results confirmed that Ca 2+ can interact with the surface functional group of C[double bond, length as m-dash]O of the C-dots, forming a stable structure surrounding the C-dot core, which contributed to a high quantum yield (QY) of 65%, excitation-independent PL behavior and absorption at 405 nm. Furthermore, the PL of the C-dots is strongly dependent on the pH, indicating that the Ca 2+ capped C-dots could be used as pH indicators. Our finding provides clear evidence for the surface-chemistry dependent PL behavior of C-dots.

Solar-driven photoelectrochemical (PEC) hydrogen production is one of the most effective strategies for solar-to-hydrogen energy conversion. Among various types of semiconductors used for PEC anodes, colloidal quantum dots (QDs) have been widely used as new and promising absorbers for PEC and other optoelectronic devices. However, currently, most efficient optoelectronic devices contain toxic Pb/Cd elements or non-earth-abundant elements (In/Ag). It is still a challenge to produce Pb/Cd-free QDs without using any toxic and non-earth-abundant elements. Here, we synthesized SnSe QDs via a diffusion-controlled hot injection approach and further stabilized the as-prepared SnSe QDs via a cation exchange reaction. The as-synthesized Zn-stabilized SnSe QDs (SnSe/ZnSe) have an orthorhombic crystal structure with indirect bandgaps ranging from 1 to 1.37 eV. Zn stabilization can significantly decrease the number of QD surface metallic Sn bonds, thereby decreasing the number of recombination centers of defects/traps. As a proof-of-concept, SnSe/ZnSe QDs are used as light absorbers for PEC hydrogen production, leading to a saturated photocurrent density of 7 mA cm -2 , which is comparable to best values reported for PEC devices based on toxic-metal-free QDs. Our results indicate that Zn-stabilized SnSe QDs have great potential for use in emerging optoelectronic devices.

Chemotherapy is an important method for treating breast cancer. However, multidrug resistance is one of the major challenges in breast cancer chemotherapy. There is an urgent need to develop novel, effective antitumor strategies that will perfect existing therapeutic regimens. In this study, the double-targeted nanocarrier, Quercetin-3'3-dithiodipropionic acid-Astragalus polysaccharides-Folic acid (QDAF), was successfully synthesized and self-assembled into a neoteric nano-targeted delivery strategy, named nano-pomegranates, and which were utilized to effectively inhibit multidrug resistance in estrogen receptor α (ERα)-positive breast tumor. The outstanding abilities of nano-pomegranates to release the drug in a reducing environment was determined by in vitro release assay. The cellular studies in MCF-7 cells were examined that nano-pomegranates have remarkable efficiencies of enhancing cellular uptake, inhibition and necrosis and apoptosis. In vivo antitumor experiments showed that nano-pomegranates have better anti-tumor effects and lower systemic toxicity than free Cur. In conclusion, nano-pomegranates have great potential in anti-breast cancer treatment.

Water pollution caused by oil spillages has aroused worldwide attention. Therefore, it is of great significance to develop low-cost, environmentally friendly materials to remove oil contaminants from water. Herein, a "green" superhydrophobic sponge made from marine algae was fabricated by one-step growth of silicone nanofilaments onto a AgNP-decorated alginate sponge via chemical vapor deposition of an azeotrope of (CH 3 ) 3 SiCl and SiCl 4 . The reaction of the azeotrope with the alginate sponge was termed "instant", as it took only a few minutes (5 min) at room temperature to achieve superhydrophobicity (152.0°). Such sponges resist high temperatures, UV irradiation, organic solvents, and mechanical abrasion without losing the superhydrophobicity. The sponges absorbed oil droplets within seconds (1.3-7.0 s) with 11.7-17.1 g/g of sorption capacities for oils of different viscous levels (0.56-1775.00 mPa·s). These sponges could retain 90% of the initial oil sorption capacities after 10 consecutive oil sorption/desorption cycles. Benefiting from the superhydrophobicity and superoleophilicity, the sponges also exhibited high efficiency in oil/water mixture separation. Once the oil/water mixture was injected into the sponge, oil drops were retained in inner pores while water was rejected and spouted from the surface. These excellent performances make the resultant sponge a competitive material for oil spill emergency remediation., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)

The pyrolysis behavior of corn stover and polypropylene during co-pyrolysis was studied using a tube furnace reactor. The effects of mixing ratio of corn stover and polypropylene, pyrolysis temperature, addition amount of catalyst (HZSM-5) and reaction atmosphere (N 2 and CO 2 ) on the properties of pyrolysis products were studied. The results showed that co-pyrolysis of corn stover and polypropylene can increase the yield of pyrolysis oil. When corn stover:polypropylene = 1:3, the yield of pyrolysis oil was as high as 52.1%, which was 4.5% higher than the theoretical value. With the increase of pyrolysis temperature, the yield of pyrolysis oil increased first and then decreased, and reached the optimal yield at 550 °C. The addition of catalyst (HZSM-5) reduced the proportion of oxygenates and promoted the generation of aromatic hydrocarbons. CO 2 has a certain oxidation effect on the components of pyrolysis oil, which promoted the increase of oxygen-containing aromatics and the reduction of deoxy-aromatic hydrocarbons. This study identified the theoretical basis for the comprehensive utilization of plastic and biomass energy.

In this study, Cu/Ag/polydopamine (PDA)/polyester (PET) fabrics were fabricated for multi-functional textiles. The PET fabrics were firstly modified by dopamine to form a polydopamine (PDA) layer on the fiber surface, then Ag nanoparticles (Ag NPs) were anchored on fiber surface through chelation between PDA and Ag + ions, and the Ag NPs were further used as catalytic seeds for in situ reduction of Cu nanoparticles (Cu NPs). The surface morphology, chemistry, and crystalline structure of the prepared PET fabrics were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). As expected, Cu NPs were evenly dispersed on the surface of fibers. The Cu/Ag/PDA/PET fabrics showed good antibacterial property against Escherichia coli and exhibited excellent electromagnetic interference (EMI) shielding ability. The Cu/Ag/PDA/PET fabrics with high performance antibacterial and EMI shielding properties can be applied as functional protective textiles.

Luminescent solar concentrators (LSCs) are light-weight, semitransparent and large-area sunlight collectors for solar-to-electricity conversion. To date, carbon quantum dots (C-QDs) have attracted a lot of attention due to their size/shape/composition tunable optical properties, high quantum yield, excellent photostability, lower toxicity and simple synthetic methods using earth-abundant and low-cost precursors. However, due to the overlap between their absorption and emission spectra, it is still challenging to fabricate high-efficiency LSCs based on C-dots. In this work, we used C-QDs to fabricate semi-transparent large-area laminated LSCs (10 × 10 cm 2 ). C-QDs have the absorption spectrum ranging from 300 to 550 nm with a Stokes shift of 0.6 eV. By optimizing the concentration of C-QDs, the laminated LSC exhibits a highest η opt of 1.6%, which is 1.6 times higher than that of a single-layer LSC (100 mW cm -2 ). In addition, the laminated LSC exhibits a power conversion efficiency of 0.7% under natural sunlight illumination (62 mW cm -2 ) with excellent photostability. These findings suggest that laminated structured LSCs could be used for efficient solar energy harvesting compared to single layer or tandem structured LSCs based on colloidal C-QDs., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

In this paper, the crystalline modification of isotactic polypropylene (PP) with a rare earth β nucleating agent (WBG) with different ultrasound conditions was investigated by scanning electron microscopy (SEM), wide-angle X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The relationship between the ultrasound conditions and the crystalline structure, as well as the mechanism for the behavior, were revealed. SEM showed that the dispersion of the nucleating agent in the PP matrix was better at shorter ultrasound distances. In addition, the higher the water cooling temperature, the better the nucleating agent was dispersed in the PP matrix. The results of XRD and DSC showed that the crystallinity and the relative content of the β -crystal were increased with nearer ultrasound distance, as well as increased in higher water cooling temperatures. In particular, under the same conditions, the crystallinity and the relative content of the β -crystal after ultrasonic treatment were much higher than those without ultrasound., Competing Interests: The authors declare no conflict of interest.

One of the major obstacles to the widespread use of pyrolysis oil is its high oxygen content, with oxygen atoms being mainly present in the hydroxyl and the carboxyl groups. Therefore, quantitative and accurate characterization of oxygen-containing functional groups is of great significance. This study employed 31 P NMR to conduct in-depth studies on several model compounds including four kinds of alcohols and carboxylic acids. The model compounds have been investigated for stability in 31 P NMR solution for both short storage (4 hours) and long storage (14 days), namely by in and ex situ monitoring. The experimental phenomena indicates that carboxylic hydroxyl has poor stability compared to alcohols hydroxyl group, which is reflected in the amount of alcohol compounds remaining over 90% after long-term storage. Among the carboxylic acids used in the study, aromatic acids are relatively stable. Interestingly, oxalic acid is extremely unstable and completely decomposed in the first hour, while formic acid had only a small amount left after one day of storage. Therefore, the optimum time for the preparation, storage and upgrading of the pyrolysis oil can be determined by analysis of the stability of the oxygen-containing functional groups in 31 P NMR solution to ensure accuracy. Moreover, according to the results of the 31 P NMR and other characterization methods, it can been seen that water was formed during the decomposition of all the model compounds. This is a report on the quantitative characterization of different oxygen-containing functional groups representing pyrolysis oil and the first study on the similarities and differences of the decomposition of carboxylic acids and alcohols in 31 P NMR solution. The results of this in-depth investigation can provide important assistance in research that will further upgrade and apply pyrolysis oil., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (This journal is © The Royal Society of Chemistry.)

Pyrolysis of raw pine bark, pine, and Douglas-Fir bark was examined. The pyrolysis oil yields of raw pine bark, pine, and Douglas-Fir bark at 500 °C were 29.18%, 26.67%, and 26.65%, respectively. Both energy densification ratios (1.32-1.56) and energy yields (48.40-54.31%) of char are higher than pyrolysis oils (energy densification ratios: 1.13-1.19, energy yields: 30.16-34.42%). The pyrolysis oils have higher heating values (~25 MJ/kg) than bio-oils (~20 MJ/kg) from wood and agricultural residues, and the higher heating values of char (~31 MJ/kg) are comparable to that of many commercial coals. The elemental analysis indicated that the lower O/C value and higher H/C value represent a more valuable source of energy for pyrolysis oils than biomass. The nuclear magnetic resonance results demonstrated that the most abundant hydroxyl groups of pyrolysis oil are aliphatic OH groups, catechol, guaiacol, and p -hydroxy-phenyl OH groups. The aliphatic OH groups are mainly derived from the cleavage of cellulose glycosidic bonds, while the catechol, guaiacol, and p -hydroxy-phenyl OH groups are mostly attributed to the cleavage of the lignin β-O-4 bond. Significant amount of aromatic carbon (~40%) in pyrolysis oils is obtained from tannin and lignin components and the aromatic C-O bonds may be formed by a radical reaction between the aromatic and aliphatic hydroxyl groups. In this study, a comprehensive analytical method was developed to fully understand and evaluate the pyrolysis products produced from softwood barks, which could offer valuable information on the pyrolysis mechanism of biomass and promote better utilization of pyrolysis products.

Abundant studies have been completed about factors on the pyrolysis of coal and biomass. However, few articles laid emphasis on using CO 2 as a carrier gas to explore the compositional changes of pyrolysis products in coal and biomass pyrolysis for industrial application and commercial value. The experiments on coal and biomass pyrolysis in N 2 and CO 2 using a horizontal tube furnace were conducted at 500 °C. The impact of introducing CO 2 on the pyrolysis process of bituminous coal and Platanus sawdust was investigated. The nuclear magnetic resonance (NMR) spectra of tar and the characterizations of char including Brunner-Emmet-Teller (BET) measurements, scanning electron microscope (SEM), Fourier transform infrared (FT-IR) spectroscopy, and element analysis were studied. The findings in light of the experimental results show that introducing CO 2 enhances the coal and biomass pyrolysis in a solid product by promoting the fracture of hydroxyl groups. It also promotes tar decomposition and the release of volatiles, which contribute to the occurrence of char with high porosity, pore volume, and specific surface. Furthermore, higher specific surface enhances the adsorption performance of char as active carbon. Simultaneously, CO 2 promotes the increase of oxygen-containing aromatics especially the methoxy-containing aromatics, and the decrease of deoxygenated aromatic hydrocarbons in pyrolysis oils. In addition, the introduction of CO 2 changes the amount of aliphatic compounds in various ways for the pyrolysis of coal and biomass. From a perspective of business, the changes in the composition of pyrolysis oil brought by CO 2 may create new value for fuel utilization and industrial products.

Artemisia vulgaris is an economic plant that is spreading widely in central China. Its unused bast generates a large amount of biomass waste annually. Utilizing the fibers in Artemisia vulgaris bast may provide a new solution to this problem. This research attempts to strengthen the understanding of Artemisia vulgaris by analyzing its fiber compositions and preparing micro- and nano-cellulose fibers, which can be used as raw materials for composites. In this work, Artemisia vulgaris bast powder (AP) and microcellulose and nanocellulose fibers (AMFs and ANFs) were produced and characterized by optical microscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TG), and bacteriostatic test. The results indicated that cellulose, hemicellulose, and lignin were the main components in the Artemisia vulgaris bast. The cellulose content reached 40.9%. The Artemisia vulgaris single fibers were microcellulose fibers with an average length of 850.6 μm and a diameter of 14.4 μm. Moreover, the AMF had considerable antibacterial ability with an antibacterial ratio of 36.6%. The ANF showed a length range of 250-300 nm and a diameter of 10-20 nm, and it had a higher crystallinity (76%) and a lower thermal stability (initial degradation temperature of 183 °C) compared with raw ANF (233 °C). This study provides fundamental information on Artemisia vulgaris bast cellulose for its subsequent utilization., Competing Interests: The authors declare no conflict of interest.

The pyrolytic behavior of several biomass components including cellulose, hemicellulose, lignin, and tannin, from two sources of waste biomass (i.e., pine bark and pine residues) were examined. Compared to the two aromatic-based components in the biomass, carbohydrates produced much less char but more gas. Surprisingly, tannin produced a significant amount of water-soluble products; further analysis indicated that tannin could produce a large amount of catechols. The first reported NMR chemical shift databases for tannin and hemicellulose pyrolysis oils were created to facilitate the HSQC analysis. Various C⁻H functional groups (>30 different C⁻H bonds) in the pyrolysis oils could be analyzed by employing HSQC-NMR. The results indicated that most of the aromatic C⁻H and aliphatic C⁻H bonds in the pyrolysis oils produced from pine bark and pine residues resulted from the lignin and tannin components. A preliminary study for a quantitative application of HSQC-NMR on the characterization of pyrolysis oil was also done in this study. Nevertheless, the concepts established in this work open up new methods to fully characterize the whole portion of pyrolysis oils produced from various biomass components, which can provide valuable information on the thermochemical mechanisms.

Biodegradable porous scaffold is widely used in the field of tissue engineering. Scaffolds were required to have proper microstructure with suitable size, gradient, shape and porosity to mimic the specific three-dimensional structure of extracellular matrix. Taken the simple technique of freeze-drying, the nucleation and growth of ice crystals were affected by thermal behavior of solution during freezing process, which could be controlled to tailor and predict the pore structure in scaffold. This paper aimed to reveal the effect of containers' heat-transfer capability on the thermal behaviors of solution, and then its influence to pore structure in scaffold. Four containers with different heat transfer capacity were adopted for cooling model to achieve different thermal characterizations within solution during cooling process. The vertical cross-section of scaffold was observed by scanning electron microscopy. The porosity and tensile properties of scaffold were measured to depict scaffold characteristics. Scaffolds fabricated by containers with λ/d = 20,000, 3000 and 450 W/m 2 ·°C showed cellular pores with gradient. With the decrease of λ/d, pores in scaffold were enlarged, and the wall between neighboring pores also became thicker. Pillared pores were produced only in container with λ/d = 50 W/m 2 ·°C, oriented along the vertical direction without gradient. This process demonstrated that by altering the container of cooling model, scaffold microstructure could be tailored., (Copyright © 2018. Published by Elsevier B.V.)

In this paper, the crystalline modification of a rare earth nucleating agent (WBG) for isotactic polypropylene (PP) based on its supramolecular self-assembly was investigated by differential scanning calorimetry, wide-angle X-ray diffraction and polarized optical microscopy. In addition, the relationship between the self-assembly structure of the nucleating agent and the crystalline structure, as well as the possible reason for the self-assembly behaviour, was further studied. The structure evolution of WBG showed that the self-assembly structure changed from a needle-like structure to a dendritic structure with increase in the content of WBG. When the content of WBG exceeded a critical value (0.4 wt%), it self-assembled into a strip structure. This revealed that the structure evolution of WBG contributed to the K β and the crystallization morphology of PP with different content of WBG. In addition, further studies implied that the behaviour of self-assembly was a liquid-solid transformation of WBG, followed by a liquid-liquid phase separation of molten isotactic PP and WBG. The formation of the self-assembly structure was based on the free molecules by hydrogen bond dissociation while being heated, followed by aggregation into another structure by hydrogen bond association while being cooled. Furthermore, self-assembly behaviour depends largely on the interaction between WBG themselves., Competing Interests: We declare we have no competing interests.

This paper presents a study of the bending flexibility of fully covered biodegradable polydioxanone biliary stents (FCBPBs) developed for human body. To investigate the relationship between the bending load and structure parameter (monofilament diameter and braid-pin number), biodegradable polydioxanone biliary stents derived from braiding method were covered with membrane prepared via electrospinning method, and nine FCBPBSs were then obtained for bending test to evaluate the bending flexibility. In addition, by the finite element method, nine numerical models based on actual biliary stent were established and the bending load was calculated through the finite element method. Results demonstrate that the simulation and experimental results are in good agreement with each other, indicating that the simulation results can be provided a useful reference to the investigation of biliary stents. Furthermore, the stress distribution on FCBPBSs was studied, and the plastic dissipation analysis and plastic strain of FCBPBSs were obtained via the bending simulation., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Porous scaffold is widely used in the field of tissue engineering. However, the anisotropic structure of actual extracellular matrix (ECM) of human tissue pose a challenge to the scaffold structure that pore size should be changed in gradient. Here we report a stage cooling method to fabricate alginate scaffold with gradient pores. Eight cooling models were set according to different temperature steps, different initial temperature, and different time duration. The thermal characterization of solution during cooling process were recorded and scaffold morphology were observed. The results revealed that the temperature steps mainly affected pore shape, while the initial temperature and time duration mainly affected pore size. By altering the initial temperature and time duration, scaffold exhibited cellular and gradually enlarged pores on the vertical axial direction (10-65 μm at base, 50-141 μm at top). With this stage cooling method, pore shape and pore size could be easily tailored and scaffold with gradient structure could be fabricated.

Degumming is the dominant method to obtain lignocellulosic fibers in the textile industry. Traditionally, wet chemistry methods are used to monitor the evolution of major chemical components during the degumming process. However, these methods lack the ability to provide spatial information for these heterogeneous materials. In this study, besides wet chemistry and scanning electron microscopy (SEM) analysis, a Fourier-transform infrared microspectroscopy (FTIRM) method was employed to monitor the changes in spatial distribution of the main chemical components on the kenaf surface during a steam explosion followed by chemical degum process. The results showed that hemicellulose and lignin were degummed at different rates, and the mechanisms of their degumming are different. The infrared microspectral images revealed the distribution changes of chemical components on the fiber bundle surface during the process, indicating that FTIRM is an effective tool to analyze the degumming process and improve degumming methods.

Plant fibrous material is a good resource in textile and other industries. Normally, several kinds of plant fibrous materials used in one process are needed to be identified and characterized in advance. It is easy to identify them when they are in raw condition. However, most of the materials are semi products which are ground, rotted or pre-hydrolyzed. To classify these samples which include different species with high accuracy is a big challenge. In this research, both qualitative and quantitative analysis methods were chosen to classify six different species of samples, including softwood, hardwood, bast, and aquatic plant. Soft Independent Modeling of Class Analogy (SIMCA) and partial least squares (PLS) were used. The algorithm to classify different species of samples using PLS was created independently in this research. Results found that the six species can be successfully classified using SIMCA and PLS methods, and these two methods show similar results. The identification rates of kenaf, ramie and pine are 100%, and the identification rates of lotus, eucalyptus and tallow are higher than 94%. It is also found that spectra loadings can help pick up best wavenumber ranges for constructing the NIR model. Inter material distance can show how close between two species. Scores graph is helpful to choose the principal components numbers during the model construction.

Two types of PdCu 2 nanoparticles were prepared through one-pot synthesis and a two-step reducing process, named as PdCu 2 -1 and PdCu 2 -2, respectively. The morphology and structure of as-prepared samples were investigated by transmission electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and inductively coupled plasma-optical emission spectrometry. Results showed that more Pd atoms were buried in the inside of PdCu 2 -1, whereas more available Pd sites were distributed on the surface of PdCu 2 -2. The electrochemical measurements indicated that both PdCu 2 -1 and PdCu 2 -2 nanoparticles showed a higher electrocatalytic activity than that for pure Pd nanoparticles. In particular, PdCu 2 -2 predictably exhibited a better stability and durability as well as a lower onset potential and a higher catalytic current density than that of PdCu 2 -1 toward ethanol oxidation in alkaline media. On the basis of these studies, the formation mechanisms of both the PdCu 2 catalysts and the relationship between their structure and properties were discussed in this paper.

Hierarchical colloidal nanocrystal assemblies (CNAs) of ZnFe₂O₄ have been synthesized controllably by a solvothermal method. Hollow ZnFe₂O₄ spheres can be formed with the volume ratios of ethylene glycol to ethanol of 1:4 in the starting systems, while solid ZnFe₂O₄ CNAs are obtained by adjusting the volume proportion of ethylene glycol to ethanol from 1:2 to 2:1. Magnetometric measurement data showed that the ZnFe₂O₄ CNAs obtained with the volume ratios of 1:2 and 1:1 exhibited weak ferromagnetic behavior with high saturation magnetization values of 60.4 and 60.3 emu·g -1 , respectively. However, hollow spheres showed a saturation magnetization value of 52.0 emu·g -1 , but the highest coercivity among all the samples. It was found that hollow spheres displayed the best ability to adsorb Congo red dye among all the CNAs. The formation mechanisms of ZnFe₂O₄ CNAs, as well as the relationship between their structure, crystallite size, and properties were discussed based on the experimental results.

This study used Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and Fourier transform near-infrared (FT-NIR) spectroscopy with principal component regression (PCR) and partial least squares regression (PLS) to build hardwood prediction models. Wet chemistry analysis coupled with high performance liquid chromatography (HPLC) was employed to obtain the chemical composition of these samples. Spectra loadings were studied to identify key wavenumber in the prediction of chemical composition. NIR-PLS and FTIR-PLS performed the best for extractives, lignin and xylose, whose residual predictive deviation (RPD) values were all over 3 and indicates the potential for either instrument to provide superior prediction models with NIR performing slightly better. During testing, it was found that more accurate determination of holocellulose content was possible when HPLC was used. Independent chemometric models, for FT-NIR and ATR-FTIR, identified similar functional groups responsible for the prediction of chemical composition and suggested that coupling the two techniques could strengthen interpretation and prediction., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

In this study, a wet spinning method was applied to fabricate regenerated cellulose fibers filled with low graphene loading which was systematically characterized by SEM, TEM, FTIR and XRD techniques. Subsequently, the mechanical and thermal properties of the resulting fibers were investigated. With only 0.2 wt% loading of graphene, a ∼ 50% improvement of tensile strength and 25% enhancement of Young's modulus were obtained and the modified Halpin-Tsai model was built to predict the mechanical properties of composite fibers. Thermal analysis of the composite fibers showed remarkably enhanced thermal stability and dynamic heat transfer performance of graphene-filled cellulose composite fiber, also, the presence of graphene oxide can significantly enhance the thermal conductivity of the composite fiber. This work provided a facile way to improve mechanical and thermal properties of regenerated cellulose fibers. The resultant composite fibers have potential application in thermal insulation and reinforced fibrous materials., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Kenaf has a high content of gum that is difficult to remove. Traditional chemical degumming process causes serious environmental pollution. To solve the problem, we developed a new method to degum kenaf. We pretreated the kenaf with steam explosion followed by ultrasonic treatment. We chose the single factor tests to select the ultrasonic frequency, sodium hydroxide concentration and processing time. Combined with orthogonal tests, we found that the optimum conditions were as follows: ultrasonic frequency was 28 kHz, sodium hydroxide concentration was 2%, and processing time was 60 min. Under these conditions, the residual gum of kenaf fiber was 9.72% and the fineness was 139.45 N(m). Steam explosion combined with ultrasonic method is effective in degumming of kenaf.

The antifungal properties and cytotoxicity of alginate fibers were investigated to widen their application in tissue engineering. Calcium, zinc, and copper alginate fibers were separately prepared by replacing Na(+) with Ca(2+), Zn(2+), or Cu(2+). The antifungal properties of the three alginate fibers were studied after coming into contact with Candida albicans. Then, the fungal inhibitory rates were measured using the plate-count method following shake-flask test. Moreover, an inhibition-zone test and observation by scanning electron microscopy were carried out. The inhibitory rate of the calcium, copper, and zinc alginate fibers were, respectively, 49.1, 68.6, and 92.2 %. The results from inhibition-zone test and shake-flask test show that zinc alginate fibers have the most significant antifungal action and that copper alginate fibers have obvious inhibitory action, but the calcium alginate fibers have weak inhibitory effects. The scanning electron micrographs similarly illustrate that the fungal surfaces show most scraggly after the interaction between C. albicans and zinc alginate fibers. Moreover, the relative growth rates of zinc or calcium alginate fibers in human embryonic kidney cells and human fibroblast cells were more than 100 %. No significant results were obtained (P>0.05). The calcium alginate fibers in human fibroblast cells were not much different from the negative control group (P>0.05). However, zinc alginate fibers had a significant change (P<0.05). Therefore, the excellent antifungal property of zinc alginate fibers demonstrates potential application in skin tissue engineering comparing with calcium or copper alginate fibers.

The relation between copper alginate fibers and immunotoxicity in animals was studied by dividing guinea pigs and mice into control groups and experimental groups. Varied weights of fibers were subcutaneously embedded in the experimental groups, whereas the control groups were operated on simulatively. Morphology analysis, erythrocyte osmotic fragility (EOF) test, direct plaque-forming cell (PFC) assay, quantitative hemolysis spectrophotometry (QHS) assay, macrophages phagocytosis assay, and pathology analysis were used to examine morphology, microstructure, and immunotoxicity. With increasing doses of copper alginate fibers, the EOF of experimental groups increased in contrast with the control group. Moreover, the antibody level decreased based on the results of the PFC and QHS assays, and macrophages phagocytosis descended in relation to dose. However, the immune functions were weakened without time dependence. According to pathologic photographs, the partial organs were damaged, implying bad histocompatibility. Hence, copper alginate fiber is proved to be a harmful material for medical devices.