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The onset temperature of smoldering for calcium alginate fibers was determined across several densities. Experimental results and theoretical calculations proved that as the density of calcium alginate fibers increases, its smoldering occurrence temperature decreases. From the experiments, the thermal stability of calcium alginate fibers decreases with increasing density. It is concluded that the mass loss of calcium alginate fiber during smoldering varies significantly with density, with higher density exhibiting higher mass loss.

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A polyelectrolyte system consisting of sodium alginate (SA) and quaternary ammonium chitosan (QAC) blended with polydopamine-coated copper sulfide particles (CuS@PDA) was chosen to investigate the function of CuS@PDA in the uniform binary blending of anionic and cationic polyelectrolytes in detail. A smart composite fiber SA/QAC/CuS@PDA was prepared via a dry-wet spinning technique. With the addition of CuS@PDA (about 4.3 % in fiber), the as-prepared SA/QAC/CuS@PDA-0.50 fibers (SQCuS@P-0.50 SCFs) showed notably enhanced intensity 359.2 MPa, excellent moisture response, and photothermal conversion performance, with the temperature increasing from 25.9 to 80.7 °C as irradiated under a 980 nm infrared lamp at distance 20 cm away for 120 s. The photothermal performance was maintained after 6 lighting on-and-off cycles. The tensile strength decreased ~23.8 % after 4 cycles, then remained fixed. The diameter increases to ~480 % in wet state but decreases to the original size in dry state for 10 cycles. When the fabric with 90 wt% SQCuS@P-0.50 SCFs was used as a water evaporator, the water evaporation rate and efficiency were 1.68 kg·m-2·h-1 and 102 % under 1 sun irradiation. This work provides a simple and ecofriendly strategy for fabricating photothermal fabrics by designing and preparing composite fibers.

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To solve the inherent problems of conductive hydrogels, such as relatively low mechanical properties and fatigue resistance, inability to work after water loss, and difficulty weaving. In this study, the borax-crosslinked polyvinyl alcohol/k-carrageenan (kC) conducting hydrogels (BPKKOH) were prepared by a simple one-pot method, and KOH treatment was used instead of the cumbersome and time-consuming freeze-thaw cycle to improve the comprehensive properties. The KOH treatment increased the hydrogel hydrogen bonding content by 7.72 % and synergized with the induction of kC by K+ to enhance the tensile and compressive strengths by 8.12 and 34.6 times, respectively. Meanwhile, the BPKKOH hydrogel's fatigue resistance and shape recovery after water loss were improved. Additionally, the BPKKOH hydrogels can be monitored for finger bending, showing clear and stable differences in electrical signals. BPKKOH hydrogels combined with Morse code realize applications in information transmission and encryption/decryption. Notably, introducing KOH ensures the molding and preparation of BPKKOH hydrogel fibers while having good signal responsiveness and monitoring ability. More importantly, it can be woven into fabrics that can be loaded with heavy weights, which has the potential to be directly applied in smart wearables. This work provides new ideas for applying flexible sensors and wearable smart textiles.

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To address the limitations of gel-based adsorbents, such as inadequate mechanical strength, low adsorption capacity, and limited reusability, this study presents an innovative approach employing a dual network gel. The dual network consists of calcium alginate (CA) ionic crosslinked organic networks, and vinyl silica-based nanoparticles (VSNP) as crosslinking agents in acrylic acid (AA) free radical polymerization networks (denoted as P (AA-co-VSNP), abbreviated as PAV). After freeze-drying, ultimately yielding an organic/inorganic hybrid dual network gel (referred to as CA/P(AA-co-VSNP), abbreviated as CPAV), enriched with abundant functional groups, thereby enhancing material reusability. To further enhance the adsorption capacity, CPAV undergoes hydrothermal reactions to obtain metal-organic frameworks (MOFs) composite dual network gel adsorbent (UiO-66@CPAV). UiO-66@CPAV exhibited a density of 0.165 g/cm3 and showcased a unique pore structure with nested macropores and mesopores, featuring a uniform distribution of pore holes. Notably, the specific surface area was measured at 96.3 m2/g, and an average pore diameter was 17.9 nm. Most impressively, the actual maximum adsorption capacity reached 841.7 mg/g, and even after 10 cycles of use, the adsorption capacity remained 91.9 % of its initial value. Overall, this research introduced a novel methodology for the development of dual network MOFs@gel adsorbents, showcasing promising advancements in the field.

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This paper presents a novel approach for the fabrication of polyvinyl alcohol (PVA)/sodium alginate (SA) aerogel fibers with a multilayered network structure using wet spinning and freeze-thaw cycling techniques. The multiple cross-linking networks regulate the pore structure, leading to the formation of stable and tunable multilevel pore architectures. PEG and nano-ZnO were successfully loaded onto the PVA/SA modified aerogel fibers (MAFs) using vacuum impregnation. MAFs exhibited excellent thermal stability at 70 °C without leakage after 24 h of heating. Furthermore, MAFs demonstrated excellent temperature regulation performance, with a latent heat of 121.4 J/g, which accounts for approximately 83 % of PEG. After modification, the thermal conductivity of MAFs was significantly improved, and they exhibited excellent antibacterial properties. Therefore, MAFs are expected to be widely used in intelligent temperature-regulating textiles.

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An in-situ compatibilized starch (St) and polyacrylonitrile (PAN) composite spinning solution was designed by preparing starch-graft-polyacrylonitrile (St-g-PAN) through graft copolymerizing acrylonitrile from soluble starch and using ammonium cerium nitrate (CAN) as initiator. As dimethyl sulfoxide (DMSO) was used as the solvent, St/St-g-PAN/PAN/DMSO spinning solution was prepared and St/St-g-PAN/PAN composite fibers were obtained by dry-wet spinning technique. The effects of air gap, coagulation bath, hot drawing and stretching, and thermal-setting process were studied in detail. Fourier transform infrared spectroscopy (FT-IR), solid state nuclear magnetic resonance (13C NMR), thermogravimetric analysis (TGA), X-ray diffraction analysis (XRD), and scanning electron microscopy (SEM) were used to characterize the structure and morphology of the copolymer and the fibers. Single fiber strength tester and sonic orientation instrument were performed to measure the fiber mechanical properties and orientation degrees. The results showed that as the grafting ratio ~150.0% and the reacting mixture containing St ~9.8%, St-g-PAN ~81.6%, and homo-PAN ~8.6% in DMSO solution with 6.0 wt% in concentration were used, the spinning parameters such as air gap ~35 mm, coagulation bath concentration ~70%, temperature ~25 °C, and positive stretching ~48%, hot drawing and stretching 6 times at 80 °C, thermal-setting at 90 °C for 3 h under constant length mode were met, composite fibers with breaking strength 3.41 cN·dtex-1, breaking elongation 14.41%, sonic orientation factor 0.625, moisture recovery ratio 10.53% under standard condition (1 atm, 22 °C, and relative humidity 65%), and boiling water shrinkage ratio 9.60% were obtained. The as prepared composite fiber was better than common viscose fiber 2.11 cN·dtex-1 and cotton fiber ~3.24 cN·dtex-1 and expected to be used in the fields of medical gauze, bandage, protective clothing, et al. besides of common textiles. The in-situ compatibilization method can be applied in preparation of other composite polymer materials.

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Nature has given us significant inspiration to reproduce bioinspired materials with high strength and toughness. The fabrication of well-defined three-dimensional (3D) hierarchically structured nanocomposite materials from nano- to the macroscale using simple, green, and scalable methods is still a big challenge. Here, we report a successful attempt at the fabrication of multidimensional bioinspired nanocomposites (fiber, films, plates, hollow tubes, chair models, etc.) with high strength and toughness through self-healing and shape-retaining methods using waterborne polyurethane (WPU) and nanocellulose. In our method, the prepared TEMPO oxide cellulose nanofiber (TOCNF)-WPU hybrid films show excellent moisture-induced self-healing and shape-retaining abilities, which can be used to fabricate all sorts of 3D bioinspired nanocomposites with internal aligned and hierarchical architectures just using water as media. The tensile and flexural strength of the self-assembled plate can reach 186.8 and 193.2 MPa, respectively, and it also has a high toughness of 11.6 MJ m-3. Because of this bottom-up self-assembly strategy, every multidimensional structure we processed has high strength and toughness. This achievement would provide a promising future to realize a large-scale and reliable production of various sorts of bioinspired multidimensional materials with high strength and toughness in a sustainable manner.

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Green and scalable production of some fibrous materials with higher fracture energy has long been the goal of researchers. Although some progress has been made in recent years in the research of materials with high fracture energy, inspired by the fiber structure of spider silk, it is still a great challenge to produce artificial fibers with extremely high toughness using a simple and green process. Here, we use the molecular and nanoscale engineering of calcium phosphate oligomers (CaP, < 1 nm) and waterborne polyurethanes (WPU) macromolecules that have strong interactions to form organic-inorganic networks just like ß-sheet crystalline and flexible amorphous regions in spider silk. Through a simple and green route based on widespread paper string processing techniques, we fabricate a strong and supertough bioinspired fiber with a high strength (442 MPa), which is 7-15 times higher than the strength of counterpart PU (20-30 MPa), and a super toughness (640 MJ m-3), which is 2-3.5 times higher than the toughness of spider dragline silk. This technique provides a strategy for industrially manufacturing spider fiber-like artificial fibers with a super toughness.

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Sodium alginate (SA) blending with quaternary ammonium chitosan (QAC) polysaccharide polyelectrolyte complex (PEC) system was chosen to research the binary blending of anionic and cationic polyelectrolytes in detail and to fabricate SA/QAC composite fibers. The potential charge and the rheology of the PEC solution were characterized through Zeta Laser Particle Size Analyzer and DV-C Rotary Rheometer, the structure and properties of the composite fiber were examined by FT-IR, XRD, SEM, EDS, and YG004 single fiber strength meter. The results showed that as the mass ratio of SA to QAC increased from 0/1 to 10/1, the state of the binary solution in water changed from transparent uniform solution to turbid solution with flocculent precipitate, then back to uniform solution, accompanied by the electrical potential change. Moreover, the electrical potential also depended on salt in solution. By using this uniform PEC solution with the mass ratio of SA to QAC 10/1 and concentration 5.5 wt% in water, SA/QAC composite fibers with excellent performances of breaking strength 2.37 cN·dtex-1 and breaking elongation 14.11%, good antibacterial and hydrophobic properties were fabricated via green wet-spinning process. The FT-IR and EDS determination indicated there formed egg-box between SA and Ca2+, cross-linked network between glutaraldehyde(GA) and SA, QAC, respectively. Depending on its mechanical, natural, and antibacterial properties, the SA/QAC composite fiber has advantages in wound dressing, medical gauze, medical absorbable suture, and tissue engineering.

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Calcium alginate (Ca-Alg) fibers are renewable fibers obtained from the ocean with essential flame retardancy, which have recently been applied as components of flame-retardant paper. However, the application of Ca-Alg fibers is limited because of their tendency to smolder. Therefore, composites papers were fabricated by blending using flame-retardant polyamide-66 (FR-PA), with a 5 wt% content of phosphorous flame retardant, which will form molten carbon during combustion. When the FR-PA content is 30% of the composite paper, FR-PA forms a compact carbon layer on the surface of the Ca-Alg fibers during combustion, which isolates the mass/heat transfer and effectively suppresses the smoldering of Ca-Alg. This consists of a condensed flame retardant mechanism. Furthermore, the combustion and thermal degradation behavior of paper were analyzed by cone calorimetry (CONE), TG and TG-IR. Ca-Alg in the composite paper decomposed and released CO2 before ignition, which delayed the ignition time. Simultaneously, the FR-PA contained in the composite paper effectively inhibited the combustion of volatile combustibles in the gas phase. Overall, FR-PA and Ca-Alg improve the thermal stability of the composite paper in different temperature regions under air atmosphere. Ca-Alg reduces the formation of aromatic products and NH3 in the composite paper under N2 atmosphere. Ca-Alg-based paper with excellent flame retardancy was successfully prepared.

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The membrane is one of the key inner parts of lithium-ion batteries, which determines the interfacial structure and internal resistance, ultimately affecting the capacity, cycling, and safety performance of the cell. In this article, an alginate-based fiber composite membrane was successfully fabricated from cellulose and calcium alginate with flame-retardant properties via a traditional papermaking process. In the membrane, the calcium alginate plays a bridging role and the cellulose acts as a filler. After 100 cycles, lithium-ion batteries by the alginate-based fiber separator exhibited better capacity retention ratios (approximately 90%) compared with those of commercial PP separators. Furthermore, the alginate-based fiber separator demonstrated fine thermal stability and electrochemical properties, showing a stable charge-discharge capability and no hot melt shrinkage at higher temperatures, which is a breakthrough in improving the safety of the cell. This research affords a new way for the large-scale fabrication of safe lithium-ion battery separators.

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Autonomous grasping with an aerial manipulator in the applications of aerial transportation and manipulation is still a challenging problem because of the complex kinematics/dynamics and motion constraints of the coupled rotors-manipulator system. The paper develops a novel aerial manipulation system with a lightweight manipulator, an X8 coaxial octocopter and onboard visual tracking system. To implement autonomous grasping control, we develop a novel and efficient approach that includes trajectory planning, visual trajectory tracking and kinematic compensation. Trajectory planning for aerial grasping control is formulated as a multi-objective optimization problem, while motion constraints and collision avoidance are considered in the optimization. A genetic method is applied to obtain the optimal solution. A kinematic compensation-based visual trajectory tracking is introduced to address the coupled affection between the manipulator and octocopter, with the advantage of discarding the complex dynamic parameter calibration. Finally, several experiments are performed to verify the effectiveness of the proposed approach.

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Fluorescent textile fibres (FTFs) are widely used in many industrial fields. However, in addition to fibres with good fluorescence, fibres with excellent colour controllability, structural stability and appropriate mechanical strength still need to be developed. In this work, CdTe/alginate composite FTFs are prepared by taking advantage of the interactions between CdTe nanocrystals (NCs) and alginate macromolecules via a wet-spinning machine with a CaCl2 aqueous solution as the coagulation bath. CdTe NCs were chemically fixed in the fibre due to the interactions among surface ligands, macromolecules and coagulators (calcium ions), which ensured the excellent dispersity and good stability of the fibres. Förster resonance energy transfer (FRET) between NCs in the fibre was found to be restricted, which means that the emission colour of the fibres was totally controllable and could be predicted. Other properties of alginate fibres, such as flame retardance and mechanical strength, were also well preserved in the fluorescent fibres. Finally, FTFs showed good selectivity toward trace Hg2+ ions over other metallic ions, and the detection could be identified by the naked eye.

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Reversible deactivation radical polymerizations (RDRPs) have proven to be the convenient tools for the preparation of polymeric architectures and nanostructured materials. When biodegradability is conferred to these materials, many biomedical applications can be envisioned. In this review, we discuss the synthesis and applications of biodegradable polymeric architectures using different RDRPs. These biodegradable polymeric structures can be designed as well-defined star-shaped, cross-linked or hyperbranched via smartly designing the chain transfer agents and/or post-polymerization modifications. These polymers can also be exploited to fabricate micelles, vesicles and capsules via either self-assembly or cross-linking methodologies. Nanogels and hydrogels can also be prepared via RDRPs and their applications in biomedical science are also discussed. In addition to the synthetic polymers, varied natural precursors such as cellulose and biomolecules can also be employed to prepare biodegradable polymeric architectures.

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To improve cancer therapeutic efficacy and avoid side effects on normal tissues, a targeted chemo-photothermal nanoplatform was designed based on transferrin-decorated and MoS2-capped hollow mesoporous silica nanospheres. MoS2 nanosheets acted as a gatekeeper to prevent the leakage of DOX from the drug delivery system as well as the photothermal agent (PTA) to improve the therapeutic effect and facilitate the NIR-triggered endosomal escape. In this work, MoS2 nanosheets were anchored on the surface of hollow mesoporous silica nanospheres (HMSNs) via the formation of disulfide bonds (-S-S), which could be easily cleaved in the presence of the intracellular GSH, leading to stimuli-responsive drug release from the hollow mesoporous silica nanocarriers. Moreover, to further improve the tumor specificity and cellular uptake of the anti-cancer drug, the nanocarrier surface was also modified with the targeting ligand transferrin via-S-S linkage. The results demonstrated that the transferrin-decorated, MoS2-capped HMSNs can be utilized as a targeting chemo-photothermal synergetic system with high therapeutic efficacy.