Coagulation Bath Research Articles

Effects of the coagulation bath on the properties of regenerated carboxymethylated cellulose films

Effects of the coagulation bath on the properties of regenerated carboxymethylated cellulose films

Investigating the impact of coagulation bath temperature on the properties of biphasic calcium phosphate/poly(vinylidene fluoride)‐based membrane scaffold via immersion precipitation

AbstractIn this study, composite membrane scaffolds comprising poly(vinylidene fluoride) (PVDF) and boron‐containing biphasic calcium phosphate (BCP) are developed using a non‐solvent‐induced phase separation technique at coagulation bath temperatures of −5, 0, 10, and 20 °C. The morphology, pore size and tensile strength of the scaffolds are primarily influenced by the bath temperature. Moreover, raising the bath temperature enhances the thermal properties and β‐crystalline phase fraction. Results demonstrate that changes in the temperature increase the surface hydrophilicity and reduce the degree of swelling. According to the in vitro bioactivity analysis, apatite growth is affected by the interactive relation between the surface of the samples and the simulated body fluid (SBF) medium, in addition to the superior bioactivity of the scaffolds. In vitro cytotoxicity assay results confirm the extensive spreading of L‐929 cells on the sample surfaces, indicating the high biocompatibility of the scaffolds. Based on these favorable properties, the novel composite membranes produced, particularly at 20 °C coagulation bath temperature, may contribute to applications in bone tissue engineering.

Swelling and dissolution behaviors of cellulose in phosphate-based ionic liquids-H2O binary systems: In-situ observation and molecular dynamics simulation

Swelling and dissolution of cellulose in ionic liquids (ILs) as the pretreatment processes are key steps for the high-value conversion and utilization of cellulose. However, the molar ratio of H2O to ILs has a significant effect on the swelling and dissolution of cellulose, and its molecular-scale mechanism is still unclear, which limits screening out the suitable ILs and recovery of ILs from coagulation bath in the spinning process. Herein, three phosphate-based ILs were chosen to couple with water as solvents for swelling and dissolution of cellulose by combining in-situ observation and molecular dynamics (MD) simulation. The results show that the redissolution time of swollen cellulose is greatly reduced, especially [Emim]DEP-H2O has the best swelling and dissolution performance for cellulose due to its high β value and low viscosity. Meanwhile, when the molar ratio of IL to H2O was more than 1: 1, the IL-H2O system still has the ability to dissolve cellulose. While with the molar ratio further decreased, cellulose was no longer dissolved and began to swell, and the fiber diameter obtained the maximum swelling rate with 40.1% at a molar ratio of 1: 3. Moreover, MD simulation was used to calculate the interaction between IL/water/cellulose, which further illustrated that the combination of IL with water molecular has a significant influence on the behavior of cellulose in IL-H2O systems at the molecular scale. Thus, the potential swelling and dissolution mechanism of cellulose in ILs-H2O binary systems was proposed based on experimental and simulation results. Furthermore, the characterization results of swollen cellulose indicate that the crystal structure and degree of polymerization (DP) were almost unchanged, but the specific surface area and pore size increased significantly, and the thermal stability and heat absorption were decreased, all the results prove that the swelling process increased the accessibility of cellulose and benefited to the subsequent dissolution. Consequently, preferable swelling and dissolving parameters of experiments and simulations will provide a new idea for the selection of suitable ILs and the recovery of ILs from a coagulation bath in the dry-wet spinning process.

COFs functionalized self-cleaning loose nanofiltration membranes for efficient dye/salt separation

In spite of the fact that loose nanofiltration membrane (LNFM) technology has certified inspiring prospects in the remediation of dyestuff-comprising wastewater, omnipresent membrane fouling deteriorates its separation competence and hinders its practical application. Herein, a neoteric LNFM with finely tuned anti-fouling and self-cleaning properties was manufactured via the reformative phase inversion procedure integrated with the correctional interfacial polymerization process. By altering the casting solution (i.e., adding nano additives) and coagulation bath (i.e., applying melamine aqueous solution rather than pure water) recipes, the porphyrin-based covalent organic framework (COF-366) and melamine monomers were introduced into the polymeric matrix ingeniously in one step, participating the subsequent interfacial polymerization reaction straightly. The COF-366 with photocatalytic degradation performance and hydrophilicity bestows the resultant LNFM with superior decomposing capacity for organic micro-pollutants under visible light irradiation and better operation durability. Moreover, this substrate-confined amine diffusion combined with the high polarity of melamine enables the formation of a thinner nanofilm for easy mass transport. The best-performing LNFM invented in this work exhibited a high water permeance up to 65 L m−2 h−1 bar−1, excellent dye retention (95.7 % against methyl blue), and salt/dye discrimination (27.1 for methyl blue and Na2SO4 selectivity) abilities. Eventually, the membrane could recover to original separation efficacy after the cyclic degradation testing. Overall, this work demonstrates an extensive perspective to pioneer an advanced self-cleaning membrane for dye/salt fractionation.

Preparation of carrageenan fibers promoted by hydrogen bonding in a NaCl coagulation bath

Carrageenan fibers developed by wet spinning have been extensively studied due to their remarkable flame-retardant characteristics. However, its mechanical properties have not been significantly improved, which limits the further development of carrageenan fibers. Traditionally, the first coagulation bath has been selected as a KCl solution, which can promote the formation of gels from carrageenan without reacting with NaOH to produce precipitates. In this study, a new type of carrageenan fiber was prepared for the first time employing an underappreciated NaCl solution as the first coagulation bath in combination with an AlCl3 coagulation bath. A comparison was made using fibers produced with KCl as the first coagulation bath under the same conditions. The potential mechanism of wet forming of carrageenan fibers was revealed using performance testing, compositional analysis, and structural characterization, which systematically investigated the differences between the two fibers. In contrast to prior studies, the NaCl coagulation bath primarily promoted hydrogen bonding between carrageenan molecular chains, and the produced fibers outperformed the KCl coagulation bath.

Homogeneous CaAlg/PES hybrid ultrafiltration membranes prepared with in situ ionic crosslinking and phase inversion method

Calcium alginate hydrogel/polyethersulfone (CaAlg/PES) hybrid membranes were synthesized via combining in situ ion crosslinking with phase conversion method. Once the Sodium alginate (NaAlg) uniformly dispersed in the casting solution contacted with Ca2+ dissolved in coagulation bath solution in the phase conversion membrane formation process, nanoscale CaAlg hydrogel was in situ formed through ion exchange and evenly dispersed in the membrane matrix. FT-IR and XPS were adopted to confirm the formation of CaAlg hydrogel distributed in PES membrane matrix. SEM, AFM, BET analysis and contact Angle analyzer were all used to characterize the surface changes of morphology, roughness and hydrophilicity in detail. Specific separation performance was also evaluated and compared by cross-flow ultrafiltration tests. Comprehensive analysis of the measured properties of all obtained membranes, when the content of NaAlg was 1.5 wt%, the CaAlg/PES hydrogel membrane M32 had the most excellent performance. The pure water flux increased from 1967 to 2193 L/m2hMPa, rejection rate of BSA was up to 99.87 %, and RFR value was almost 76.83 % after 4 cycles BSA filtration. XPS characterization of the membrane after filtration for 72 hours showed that the retention rate of Ca (2 P) reached 95 %, which further proved the stability of the membrane operation.

One-step fabrication of hetero-structured polyethersulfone hollow fiber membranes through surface segregation for pervaporation desalination

Hollow fiber membranes (HFMs) are an ideal configuration for industrial applications of pervaporation desalination (PV) membranes. Currently, the efficient fabrication of PV HFMs is restricted by multi-step post-treatment processes on their outer surfaces to form the selective layer. Herein, we utilized the surface segregation strategy to fabricate a hetero-structured HFM in one step, simultaneously forming the hydrophilic dense outer layer and the porous support layer. During hollow fiber spinning process, the amphiphilic copolymer polyvinylpyrrolidone-polyvinyl acetate (PVP-PVAc) in polyether sulfone (PES) dope solution migrated towards water contacting interface in the coagulation bath and formed the hydrophilic layer by extending hydrophilic segment outwards. This fast in-situ hydrophilization well matched the spinning efficiency. The optimal PVP-PVAc content and phase inversion temperature were investigated and the spinning parameters on the structure and performance of HFMs were studied. The HFMs prepared realized a flux of 26.70 kg m−2 h−1 and the salt rejection of 99.98 %, along with adaptability to solutions with different salinities and excellent anti-organic fouling property. This study may provide a facile method to fabricate HFMs with desirable PV desalination performance and scaling-up potential.

Regenerated cellulose films with controllable microporous structure for enhanced seed germination

In this work, the preparation of high-performance and porous regenerated cellulose (RCNH) films for seed germination application were investigated. The films were prepared from bamboo-based cellulose carbamate-NaOH/ZnO/urea and coagulated using environmentally friendly aqueous solution of (NH4)2SO4. The results showed that the pore size of the films could be efficiently controlled by changing the concentration and temperature of the coagulation bath. In a mild environment, the system remains undisturbed, resulting in slow diffusion between the solvent and coagulation bath. This allows for the cellulose molecular chains to align in parallel and self-aggregate, forming a three-dimensional network structure. Therefore, the best mechanical properties were demonstrated by a film coagulated using 5 wt% (NH4)2SO4 solution at 10 °C. This film showed excellent tensile strength of 108 MPa and high elongation at break (35 %). As compared to a plastic wrap, the film demonstrated higher permeability for oxygen, and a moisture retaining ability. Due to these properties, it could be used as an agricultural film to encase and promote the growth of mung bean seeds. Moreover, the film was biodegradable with a short decomposition time, losing 90.75 % of its original mass after 63 days. In a summary, this work provides a route for robust, biodegradable, and permeable regenerated cellulose films with potential applications as biodegradable agricultural mulches.

Preparation of high-performance PVDF hollow fiber microporous membranes via the c-TIPS process with water-insoluble solvent as the second solvent

Triethyl phosphate (TEP) is a promising solvent for the c-TIPS process given its high boiling point and water miscibility. However, casting solutions containing high TEP concentration generally trigger gelation, giving a dense outer surface in PVDF membrane. In this work, we fabricated PVDF hollow fiber membranes with a porous outer surface and excellent mechanical strength via a complex thermally induced phase separation (c-TIPS) method and applied them in the DCMD process. A water-insoluble solvent, dibasic ester solvents (DBEs), was used as the second solvent to modulate the phase separation process of the PVDF/TEP system. The mass transfer between the coagulation bath and the DBEs solvent was analyzed. It could decrease the polymer-solvent interactions and the rate of solvent efflux in the coagulation bath, contributing to the development of a porous membrane structure. When the weight ratio of TEP/DMA was 1, the optimized PVDF hollow fiber membrane exhibited a tensile strength of 8.34 MPa, an average pore diameter of 0.14 μm, giving the permeate flux of 18.56 ± 2.5 kg m−2 h−1 in DCMD and excellent operational stability when subjected to high brine concentration. Thus, the fabrication method shows a promising potential for tailoring the surface porosity and bulk structure. The PVDF membranes developed in this study demonstrate potential for use in membrane distillation and related applications.

Knittable hydrogel fiber with physically amorphous structure for multi-mode sensing capacities

Integrating both green forming character and multifunctionality for physically crosslinked hydrogel fibers is challenging, but intensively desirable for emerging applications. Herein, the amorphous multi-scale structure for continuously spinning polyvinyl alcohol (PVA) hydrogel fibers is achieved with an innovatively suppressed-freezing strategy. In particular, the antifreezing salt with salting-in effect is introduced into precursor solution, in which an exceptionally homogeneous yet weak approach of polymer chains is available under weakened repelling behavior of ice crystals using liquid nitrogen as the coagulation bath. Hence, a totally amorphous network with release of free hydroxyl groups is constructed for freeze-thawed PVA hydrogel fibers, which is further stabilized by water evaporation induced densification of polymer network. Such particular multi-scale structure interestingly endows the physical hydrogel fibers with tunable mechanical properties of superior extendibility, flexibility and elasticity in a wide range, along with integrated properties of excellent transparency, antifreezing and long-term stability. Moreover, the hydrogel fibers could be knitted into fabric-like materials with arbitrary shapes, of which the extendibility and toughness are tremendously improved. Notably, benefiting from the high transparency and homogeneous structure, the physical fibers and the corresponding fabrics demonstrate light transmittance ability and deformation responsiveness, which retains even in extreme condition (−196 °C). Together with ionic-conductivity, the PVA hydrogel fibers/fabrics as strain sensors intriguingly represent conductive/optical multi-mode sensations, which are capable of dynamically monitoring subtle and sophisticated human movements. The combined advantages enable this new generation of physical hydrogel fibers to promise potential for applications in wearable electronics, biomedicine, and information transmission.

Immobilization of l-asparaginase on genipin cross-linked chitosan beads shows better acrylamide diminution in cassava chips: Process optimization and characterization.

Glutaraldehyde is the conventionally used cross-linker for the activation and cross-linking of support matrices used in enzyme immobilization. However, the toxic nature of glutaraldehyde makes it unsafe for food applications, propelling the need for nontoxic cross-linkers. Genipin reacts with the primary and secondary amines generating a dark-blue colored pigment and is an attractive alternative to glutaraldehyde as a cross-linker for enzyme immobilization. Apart from its excellent cross-linking properties, genipin possesses added advantages over glutaraldehyde such as proven health benefits, biocompatibility, and biodegradability. The present study explores the application of chitosan beads cross-linked with the natural and nontoxic agent, genipin, for immobilizing l-asparaginase, aimed at its subsequent use in mitigating acrylamide formation in food products. The immobilized l-asparaginase exhibited improved functionalities such as stability, reusability, and reduction in acrylamide formation in deep-fried cassava chips. One of the limitations observed during application in the food process was the mechanical fragility of the chitosan beads during speedy stirring. This can be overcome by increasing the concentration and time of contact of the coagulant bath during the formation of chitosan beads. The drying of the enzyme-bound chitosan beads will also lead to shrinkage and prevent breakage during stirring. This study conclusively demonstrated the applicability of immobilizing l-asparaginase on genipin cross-linked chitosan beads in food-related processes.

Wet‐Printed Stretchable and Strain‐Insensitive Conducting Polymer Electrodes: Facilitating In Vivo Gastric Slow Wave Mapping

AbstractWearable and implantable devices play a crucial role in clinical diagnosis, disease treatment, and fundamental research on the body's electrophysiology and biochemical processes. Conducting polymers are emerging as promising solutions to surpass the limitations of traditional metal‐based electrodes, offering enhanced conformability, and stretchability. However, current microfabrication techniques of CP electrodes have a number of limitations. In this study, a novel wet‐printing technique is developed for the fabrication of highly stretchable poly(3,4‐ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) microelectrodes. The wet‐printing, conducted in a liquid coagulation bath, has the advantages of being non‐contact, easy and fast to perform, and capable of printing low‐viscosity inks. Wet‐printing of PEDOT:PSS lines with a width of ≈20 µm is demonstrated. By adding D‐sorbitol as a plasticizer, an ultra‐high stretchability of PEDOT:PSS electrodes, of more than 720% is achieved while the electrodes remained conductive and strain‐insensitive up to high strains. The use of PEDOT:PSS wet‐printed electrode arrays for the electrophysiological recording from the stomach is demonstrated. The stretchable electrodes conformed swell to the tissue and recorded comparable electrophysiological signals to Au‐plated electrodes in porcine and rodent animal models. The wet‐printing approach to fabricating flexible and stretchable electrode arrays using low‐viscosity, conducting inks holds promise for applications in conformable electronics.

High-barrier, flexible, hydrophobic, and biodegradable cellulose-based films prepared by ascorbic acid regeneration and low temperature plasma technologies

Regenerated cellulose (RC) films are considered a sustainable packaging material that can replace non-degradable petroleum-based plastics. However, their susceptibility to water vapor and oxygen can limit their effectiveness in protecting products. This study introduces a novel approach for enhancing RC films to create durable, flexible, hydrophobic, high-barrier, and biodegradable packaging materials. By exploring the impact of ascorbic acid coagulation bath treatment and plasma-enhanced chemical vapor deposition (PECVD) on the properties of RC films, we found that the coagulation bath treatment facilitated the organized reconfiguration of cellulose chains, while PECVD applied a dense SiOx coating on the film surface. The results demonstrated a significant enhancement in water vapor and oxygen barrier properties of the composite film, almost reaching the level of commercial barrier films. Moreover, the composite film displayed exceptional biodegradability, fully degrading in soil within 35 days. Additionally, it showcased impressive mechanical strength, hydrophobic characteristics, and freshness preservation, positioning it as a valuable option for bio-based high-barrier packaging applications.

Effect of Viscosity and Air Gap within the Spinneret on the Morphology and Mechanical Properties of Hollow-Fiber Polymer Membranes for Separation Performance.

Hollow-fiber membranes for nanofiltration were prepared from the blending of Poly (ethylene glycol) (PEG) with Poly (vinyl chloride) (PVC) with different PEG molecular weights (400 and 4000 g/mol) and PVC via a dry/wet spinning process. In the spinning process, the effects of air gap, wind-up speed, dope extrusion rate, and bore extrusion rate were examined. In addition, the different lengths of the center tube, which acted as the inner-side fiber diameter during the preparation of hollow-fiber membranes, were studied. This research was investigated in order to observe the morphological, dielectric, and dynamic mechanical thermal properties to identify a suitable preparation of a hollow-fiber membrane for feasible applications. The morphology of the PVC-580 blended PEG-400 5 weight percent hollow-fiber membrane was seen to have a dense skin on both the inner and outer fiber surface, along with a suitable dope viscosity. Moreover, it offered finger-like substructures that could provide a high applicable feed-stream permeability and selectivity. Finger-like substructures were present on the near inner fiber surface at the controlled center-tube length of 0.3 cm, more so than at the center tube of 1 cm. This was because the solvent and non-solvent in the lumen tube exchanged more quickly than they did in the coagulant bath. The effect of the wind-up speed during the spinning process was significantly influenced by an affordable hollow fiber that can be indicated by the drawing ratio (λ). It was found that the drawing ratio of 3.3 showed a thickness thinner than 2.6 and 2.0, respectively. In summary, a controlled wind-up speed, an acceptable dope viscosity, and-most importantly-an agglomerated time resulted in membrane preparation.

A facile spinning approach towards the continuous production of aligned nanocellulose films

In this work, we present an alternative approach to cellulose nanofibril film (CNF) production, taking inspiration from the wet spinning of fibers to wet spin films. During the spinning process, a CNF suspension is injected into a coagulation bath, where the partially aligned CNF network is locked. The CNF alignment of the dry films is then detected by wide angle X-ray scattering (WAXS). The comparison between the ultimate strengths and strengths at breaks of the films produced with different process parameters, including the suspension injection rate, bath pH, and bath flow rate, indicated no significant change in mechanical properties, suggesting a reliable and constant outcome for large-scale film fabrication. Furthermore, the produced films demonstrated high total light transmittance of 93 % at the wavelength of 550 nm, making them suitable for optoelectronic applications. Polarized optical microscopy revealed that even a low degree of CNF alignment can lead to anisotropic optical properties. Moreover, an anisotropic response to humidity was observed, in which the films preferentially bend in the perpendicular direction of the CNF orientation, thus opening a way for humidity-driven actuators.

Manufacturing of Continuous Core–Shell Hydrated Salt Fibers for Room Temperature Thermal Energy Storage

The encapsulation ofsalt hydrate phase change materials (PCMs) in uniform microscale bodies has yetbeen reported in research due in part to the delicate relationship betweenthermal performance and water‐to‐salt ratios which are easily altered duringmanufacturing. Herein, core–shell composite fibers comprised of a salt hydratePCM core and a poly(acrylonitrile) (PAN) shell are wet spun in a continuousprocess using a syringe pump and coaxial die. The PCM phase comprises calciumchloride hexahydrate (CaCl2·6H2O) with strontium chloride hexahydrate(SrCl2·6H2O) (3 wt%) and fumed silica(SiO2) (2 wt%) as additive, acomposition that is prepared from homogenous melt at 40 °C. 15 wt% PAN indimethylsulfoxide solvent is used to prepare the shell‐forming polymer gel. PCM and polymer gel injectionrates of 10–40 mL h−1 are used tospin coaxial fibers through a coagulation bath, yielding continuousmicrotubules with diameters in the range of 850–1500 μm. Cyclic testing showsthat after 1000 cycles, melting enthalpies incurred only a 3.5% decline from 131.46 to 126.9 J g−1. Success hereovercomes several coincidental drawbacks of PCM fiber performance andmanufacturing and delivers the first example of scalable roll‐to‐roll PCM fiber produced by wet spinning forbuilding material applications.

Adsorption of steroid hormone micropollutant by polyethersulfone ultrafiltration membranes with varying morphology

The effective removal of micropollutants necessitates the use of dense membranes, such as thin-film composite (TFC) reverse osmosis (RO) and nanofiltration (NF) membranes. TFCs have a polyamide active layer interfacially polymerized on a support layer that is typically made of polysulfone (PSu) or polyethersulfone (PES). Retention by NF and RO is often incomplete because micropollutants are adsorbed to the polymer material and subsequently permeate via a combination of convection and diffusion, which evidences a breakthrough curve. When describing breakthrough phenomena, the role of the support membrane is commonly neglected, even though the adsorption in this layer can be significant. This work investigated the adsorption of steroid hormone micropollutants (17β-estradiol, E2) by fabricated and commercial PES ultrafiltration membranes with varying morphology.By increasing the coagulation bath temperature between 10 and 70 °C, the pure water permeability increased from 13 to 3800 L/m2·h−1·bar−1, and consequently, the average pore size rose from 12 to 191 nm. The fabricated membranes with smaller pore sizes showed higher E2 removal via adsorption which can be attributed to the higher internal surface area. The adsorbed mass of fabricated PES membranes (using dimethylformamide (coded as PDG) and N-methyl-2-pyrrolidone (coded as PNG) and PES (Istanbul Technical University (ITU), with non-woven supports) varies from 0.30 to 0.60, 0.27–0.60 and 1–1.2 ng·cm−2, respectively. These values are lower than the adsorbed masses with commercial Biomax (Millipore Inc.) membranes (0.5–2.0 ng·cm−2). Ultrafiltration membranes used as support for composite membranes, nanofiltration or as filters in sample preparation benefit from lower micropollutant adsorption.

On the role of the porous support membrane in seawater reverse osmosis membrane synthesis, properties and performance

In this study, we explore the role of the polysulfone (PSU) support membrane skin-layer and whole-body pore morphology on the physical-chemical properties and separation performance of hand-cast polyamide-PSU (PA-PSU) composite seawater reverse osmosis (SWRO) membranes. We tailor the support membrane pore morphology by varying the PSU concentration and the coagulation bath temperature. In order to isolate the impacts of the PSU support, all of the porous supports are coated using identical m-phenylene diamine (MPD) and trimesoyl chloride (TMC) solution compositions, reaction conditions, and post-treatments. As PSU concentration increases, PSU support membrane pore size, surface and body porosity, water permeability, MPD mass uptake (by the PSU support), and PA-PSU composite membrane water permeability decrease, while MPD and TMC conversion, PA film mass and thickness, crosslinking degree (XD), and PA-PSU composite membrane NaCl rejection increase. As PSU support membrane coagulation bath temperature increases, support membrane pore size, surface and body porosity, MPD uptake, PA film mass, thickness and XD, MPD and TMC conversion, and NaCl rejection increase, while composite PA-PSU membrane water and NaCl permeability decrease. Composite membrane permeabilities were 70–90 percent of the (theoretical) unsupported PA film permeabilities due to the high XD and low PA coating film thickness. Composite PA-PSU membrane water/salt permeabilities both correlate most strongly with PA coating film mass/thickness and XD, which in turn correlate most strongly with TMC conversion. The key to increasing water permeability is lower PA film mass/thickness and XD with higher support membrane surface pore size and porosity. In contrast, the key to increasing NaCl rejection is higher PA film mass/thickness and XD with lower support membrane surface pore size and porosity.

Selective production of high-value fuel via catalytic upgrading of bio-oil over nitrogen-doped carbon-alumina hybrid supported cobalt catalysts

Bio-oil derived from biomass fast pyrolysis can be upgraded to gasoline and diesel alternatives by catalytic hydrodeoxygenation (HDO). Here, the novel nitrogen-doped carbon–alumina hybrid supported cobalt (Co/NCAn, n = 1, 2.5, 5) catalyst is established by a coagulation bath technique. The optimized Co/NCA2.5 catalyst presented 100 % conversion of guaiacol, high selectivity to cyclohexane (93.6 %), and extremely high deoxygenation degree (97.3 %), respectively. Therein, the formation of cyclohexanol was facilitated by stronger binding energy and greater charge transfer between Co and NC which was unraveled by density functional theory calculations. In addition, the appropriate amount of Lewis acid sites enhanced the cleavage of the C–O bond in cyclohexanol, finally resulting in a remarkable selectivity for cyclohexane. Finally, the Co/NCA2.5 catalyst also exhibited excellent selectivity (93.1 %) for high heating value hydrocarbon fuel in crude bio-oil HDO. This work provides a theoretical basis on N dopants collaborating alumina hybrid catalysts for efficient HDO reaction.

Water-Based Continuous Fabrication of Highly Elastic Electromagnetic Fibers.

Elastic electromagnetic fibers are promising building blocks for next-generation flexible electronics. However, fabrication of elastic fibers is still difficult and usually requires organic solvents or high temperatures, restricting their widespread applications. Furthermore, the continuous production of electromagnetic fibers has not been realized previously. In this study, we propose an ionic chelation strategy to continuously produce electromagnetic fibers with a magnetic liquid metal (MLM) as the core and elastic polyurethane as the sheath in water at room temperature. Sodium alginate (SA) has been introduced to rapidly chelate with calcium ions (Ca2+) in a coagulation bath to support the continuous spinning of waterborne polyurethane (WPU) as a sheath. Meanwhile, WPU-encapsulated MLM microparticles efficiently suppress the fluid instability of MLM for continuous extrusion as the core. The resultant fiber exhibits excellent mechanical performances (tensile strength and toughness up to 32 MPa and 124 MJ/m3, respectively), high conductive stability in large deformations (high conductivity of 7.6 × 104 S/m at 580% strain), and magnetoactive properties. The applications of this electromagnetic fiber have been demonstrated by conductance-stable wires, sensors, actuation, and electromagnetic interference shielding. This work offers a water-based molecular principle for efficient and green fabrication of multifunctional fibers and will inspire a series of applications.