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Chemical warfare agents (CWAs) significantly threaten human peace and global security. Most personal protective equipment (PPE) deployed to prevent exposure to CWAs is generally devoid of self-detoxifying activity. Here we report the spatial rearrangement of metal-organic frameworks (MOFs) into superelastic lamellar-structured aerogels based on a ceramic network-assisted interfacial engineering protocol. The optimized aerogels exhibit efficient adsorption and decomposition performance against CWAs either in liquid or aerosol forms (half-life of 5.29 min, dynamic breakthrough extent of 400 L g−1) due to the preserved MOF structure, van-der-Waals barrier channels, minimized diffusion resistance (~41% reduction), and stability over a thousand compressions. The successful construction of the attractive materials offers fascinating perspectives on the development of field-deployable, real-time detoxifying, and structurally adaptable PPE that could be served as outdoor emergency life-saving devices against CWAs threats. This work also provides a guiding toolbox for incorporating other critical adsorbents into the accessible 3D matrix with enhanced gas transport properties.

Cotton fibers as original materials of cotton fabrics have a widely application due to its perfect hygroscopicity, air permeability and largest annual output. However, cotton materials have potential safety hazard during its application because of flammability (limiting oxygen index is about 18%). In order to improve the flame retardancy of cotton fibers and reduce the damage of its mechanical properties, novel P/Si based flame retardant (PFR) nanoparticles were synthesized by one-step radical polymerization. Vinyl phosphoric acid and tetramethyl divinyl disiloxane were introduced into the nanoparticles. The structure, morphology and thermal stability of PFR was characterized by fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis test (TGA). Durable flame retardant cotton fibers were prepared by dip-coating and plasma induced crosslinking methods. Micro-calorimeter (MCC) characterization showed that the peak of heat release rate (pHRR) and the total heat release were reduced by 47.3% and 29.8% for modified cotton fibers compared with pure cotton fibers. Limiting oxygen index (LOI) of modified cotton fibers was increased to 27%. The residue carbon of modified cotton fibers was 19.0% at 700 o C, while the value of pure cotton fibers was 3.0%. Besides, durability of the modified cotton fibers was approved by cyclic washing test. In addition, flame retardant mechanism was revealed by collecting and analyzing condensed and gaseous pyrolysis products. The data of FE-SEM for residue carbon, FT-IR spectra of products at different pyrolysis temperatures and pyrolysis gas chromatography mass spectrometry (Py-GC-MS) showed that PFR was a synergistic flame retardant contained barrier and quenching effecting applied on cotton materials.

One-dimensional (1D) SiO2 nanofibers (SNFs), one of the most popular inorganic nanomaterials, have aroused widespread attention because of their excellent chemical stability, as well as unique optical and thermal characteristics. Electrospinning is a straightforward and versatile method to prepare 1D SNFs with programmable structures, manageable dimensions, and modifiable properties, which hold great potential in many cutting-edge applications including aerospace, nanodevice, and energy. In this review, substantial advances in the structural design, controllable synthesis, and multifunctional applications of electrospun SNFs are highlighted. We begin with a brief introduction to the fundamental principles, available raw materials, and typical apparatus of electrospun SNFs. We then discuss the strategies for preparing SNFs with diverse structures in detail, especially stressing the newly emerging three-dimensional SiO2 nanofibrous aerogels. We continue with focus on major breakthroughs about brittleness-to-flexibility transition of SNFs and the means to achieve their mechanical reinforcement. In addition, we showcase recent applications enabled by electrospun SNFs, with particular emphasis on physical protection, health care and water treatment. In the end, we summarize this review and provide some perspectives on the future development direction of electrospun SNFs.

Fiber breakage is found to be a ubiquitous phenomenon during the thermal treatments for electrospun nanofibers, because of the presence of solvent molecules and unrelaxed assembly of polymer chains. Here a strengthening strategy is designed by introducing a pre-heating stage for the as-spun nanofibers. At a temperature above the polymer’s glass transition temperature, the chains can get sufficiently relaxed by the aid of hot solvent, and at the same time, the solvent confined in the entangled chains can fully and steadily evaporate, but not erupt, off the nanofiber, when the temperature is just as high as the boiling point. Therefore, the nanofibers become more uniform in structure and can withstand the subsequent thermal reactions. For polyacrylonitrile-based electrospinning, such strategy can improve the final tensile strength from 42 to 112 MPa for the nanofiber films.

The advancement of electrocatalytic N2 reduction reaction (NRR) toward ambient NH3 synthesis lies in the development of more affordable electrocatalysts than noble metals. Recently, various nanostructures of transition metal compounds have been proposed as effective electrocatalysts; however, they exist in the form of loose powders, which have to be immobilized on a matrix before serving as the electrode for electrolysis. The matrix, being it carbon paper, carbon cloth or metal foam, is electrocatalytically inactive, whose introduction inevitably raises the invalid weight while sacrificing the active sites of the electrode. Herein, we report on the fabrication of a flexible ZrO2 nanofibrous membrane as a novel, self-supported electrocatalyst. The heteroatom doping can not only endow the nanofibrous membrane with excellent flexibility, but also induce oxygen vacancies which are responsible for easier adsorption of N2 on the ZrO2 surface. To improve the electrocatalytic activity, a facile SILAR approach is employed to decorate it with CdS quantum dots (QDs), thereby tuning its Fermi level. To improve the conductivity, a g-C3N4 nanolayer is further deposited which is both conductive and active. The resulting hierarchically structured, self-supported electrocatalyst, consisting of g-C3N4 encapsulated ZrO2 nanofibrous membrane decorated with CdS QDs, integrates the merits of the three components, and exhibits a remarkable synergy toward NRR. Excellent NH3 yield of 6.32 × 10−10 mol·s−1cm−2 (−0.6 V vs. RHE) and Faradaic efficiency of 12.9% (−0.4 V vs. RHE) are attained in 0.1 M Na2SO4.

Ceramic aerogels are attractive for many applications due to their ultralow density, high porosity, and multifunctionality but are limited by the typical trade-off relationship between mechanical properties and thermal stability when used in extreme environments. In this work, we design and synthesize ceramic nanofibrous aerogels with three-dimensional (3D) interwoven crimped-nanofibre structures that endow the aerogels with superior mechanical performances and high thermal stability. These ceramic aerogels are synthesized by a direct and facile route, 3D reaction electrospinning. They display robust structural stability with structure-derived mechanical ultra-stretchability up to 100% tensile strain and superior restoring capacity up to 40% tensile strain, 95% bending strain and 60% compressive strain, high thermal stability from −196 to 1400 °C, repeatable stretchability at working temperatures up to 1300 °C, and a low thermal conductivity of 0.0228 W m−1 K−1 in air. This work would enable the innovative design of high-performance ceramic aerogels for various applications.

Wound dressing materials which are capable of meeting the demands of accelerating wound closure and promoting wound healing process have being highly desired. Electrospun nanofibrous materials show great application potentials for wound healing owing to relatively large surface area, better mimicry of native extracellular matrix, adjustable waterproofness and breathability, and programmable drug delivery process. In this review article, we begin with a discussion of wound healing process and current commercial wound dressing materials. Then, we emphasize on electrospun nanofibrous materials for wound dressing, covering the efforts for controlling fiber alignment and morphology, constructing 3D scaffolds, developing waterproof-breathable membrane, governing drug delivery performance, and regulating stem cell behavior. Finally, we finish with challenges and future prospects of electrospun nanofibrous materials for wound dressings.

Ramie was subjected to degumming treatment with high-boiling alcohols, which was an innovative way ahead ascribed to organosolv’s innate superiorities, namely the capability to dissolve non-cellulosic biomass obtaining separation of high-purity cellulose fibers, as well as green and ease of recovery. In the current research, effects of degumming processes with four sorts of alcohol solvents on the ramie fiber properties [degree of polymerization (DP), tenacity, linear density] and the possibility of reutilization of degumming solution were studied. Results showed that the organosolv degumming process efficiently removed non-cellulosic components and improved the DP value. In terms of the degummed fibers, except 1,4-butanediol treated fibers due to the serious damage of 1,4-butanediol to fibers, the cellulose purity was over 95%, the tenacity was 6.14–8.27 cN/dtex, and the linear density was less than 7.2 dtex. Besides, glycol treated fibers performed the most positive mechanical properties (8.27 cN/dtex) and glycerol treated fibers showed the lowest residual gum content (3.28%). Notably, the fiber still showed excellent performance after the sixth cycle treatment with glycerol, that was 3.62% of residual gum content and 4.45 cN/dtex of tenacity, which fully met the requirement of spinning process. Considering attractive characteristics of eco-friendly, high degumming efficiency, outstanding performances, and solvent recycling, this emerging method could inspire the potential application of alcohols for natural fiber isolation.

The limited mechanical properties of carbon nanofibers (CNFs) have become a severe problem hindering their wide range applications. The restricting issues are found in the whole fabrication process, including the precursor design, spinning and collection techniques, post treatments like stretching and aligning, and complicated thermal treatments involving stabilization and carbonization. Here we access the CNF development by focusing on the mechanical properties, and systematically discuss the strengthening strategies during the different fabrication stages.

Degumming bast fibers by organic solvents has been a promising method in recent years due to easy recovery and reuse of organic solvents. In this research, the possibility of ramie fiber degumming by glycol and a combination of acetic acid with glycol was studied, in which two steps were involved in the degumming process: distilled water boiling pretreatment and organosolv treatment by a combination of glycol/acetic acid (100/0, 90/10, 80/20, 70/30, 60/40, 50/50). Results displayed that the pretreatment could remove 6.99% of hemicellulose, 0.59% of lignin and 36.26% of other gums compared with raw ramie. While with organosolv treatment (130 °C, 6 h), fibers treated by glycol/acetic acid (50/50) had the best effect of removing gums. The hemicellulose and lignin content of fibers reduced by 44.81% and 54.12%, respectively (compared with raw ramie), while the residual gum content still failed to meet the requirements of spinning process. Besides, the tenacity of glycol/acetic acid treated fibers was lower than that of only glycol treated fibers (4.67 cN/dtex). Considering that the addition of acid could cause a decrease in fiber tenacity, the step of organosolv (only glycol) treatment was optimized by altering the degumming condition. The tenacity, linear density, non-cellulosic component ratio of fibers treated with the optimized condition (200 °C, 80 min) were 6.53 cN/dtex, 6.06 dtex, 5.78%, respectively, which met the needs of industrial production. Compared with the organosolv treated fibers, these properties of fibers with traditional alkaline treatment were better, but the yield (62.4%) was much lower than that of fibers treated with glycol in two degumming condition (77–82%). Considering impressive properties of the treated ramie, the method of organosolv degumming with high degumming efficiency and environmental protection would bring an innovative thought for natural fiber isolation.

Developing bioprotective materials with bactericidal activity is of great significance since it can effectively keep healthcare workers from infection by emerging infectious diseases; however, this is still a big challenge. Herein, we fabricate a novel rechargeable N-halamine antibacterial material by functionalizing electrospun poly(vinyl alcohol-co-ethylene) (EVOH) nanofibers with dimethylol-5,5-dimethylhydantoin (DMDMH). The premise of the design is that the N-halamine compound, DMDMH, can be covalently grafted on the nanofibers, endowing the EVOH nanofibrous membranes (ENM) with rechargeable and durable bactericidal activity. The as-prepared DMDMH functionalized ENM (EDNM) render rechargeable chlorination capacity (> 2000 ppm), high inactivation efficacy against bacteria (> 99.9999% within 3 min), high filtration efficiency (> 99.5%) under low air resistance, and robust mechanical properties, which are due to the synergistic effect of the unique characters of N-halamines and electrospun nanofibrous architecture. The successful synthesis of the N-halamine antibacterial membranes can serve as a functional layer of protective equipment that capable of inactivating and intercepting pathogenic bioaerosols, providing new ways into the development of new-generation antibacterial bioprotective materials.

Effective degradation of organic pollutants in wastewater is of great importance to the environment and human society. TiO2-based electrospun nanofibrous materials combining the properties of the large specific surface area, high aspect ratio, tunable compositions and structures, as well as easy to recycle, show great promise for the efficient removal of organic pollutants. In this Prospective paper, the recent progress in the degradation of organic water contaminants over visible-light-responsive TiO2-based nanofibrous materials is summarized, with emphasis on the strategies for improving the visible-light photocatalytic activity of TiO2-based nanofibrous materials. Finally, the current challenges and future outlook in this field are discussed.

Hydroxyethyl cellulose (HEC)/NaOH frozen rods were applied in the investigation of the coagulation kinetics. The influence of coagulation variables such as types of coagulants, coagulation temperature, concentration of coagulant, and content of HEC on coagulation rate was intensively studied based on boundary movement theory. It was confirmed that the coagulation of HEC was actually diffusion-controlled process and sometimes accompanied with chemical reactions. The coagulation rate of HEC rods in strong acid (sulfuric acid) exceeded that in weak acid (acetic acid), while the coagulation rate in ethanol was the slowest. It was hard to determine the coagulation rate of HEC frozen rods in deionized water without pre-solidifying because of the difficulty in keeping the cylindrical shape of sample due to the low strength of the coagulated surface layer. Besides, the increase of acid concentration, temperature, or content of HEC would contribute to the improvement of coagulation rate. This study is important for understanding and controlling the shaping process of HEC.

In this study, multiwalled carbon nanotubes (MWCNTs) were used to encapsulate a model anticancer drug, doxorubicin (Dox). Then, the drug-loaded MWCNTs (Dox/MWCNTs) with an optimized drug encapsulation percentage were mixed with poly(lactide-co-glycolide) (PLGA) polymer solution for subsequent electrospinning to form drug-loaded composite nanofibrous mats. The structure, morphology, and mechanical properties of the formed electrospun Dox/PLGA, MWCNTs/PLGA, and Dox/MWCNTs/PLGA composite nanofibrous mats were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and tensile testing. In vitro viability assay and SEM morphology observation of mouse fibroblast cells cultured onto the MWCNTs/PLGA fibrous scaffolds demonstrate that the developed MWCNTs/PLGA composite nanofibers are cytocompatible. The incorporation of Dox-loaded MWCNTs within the PLGA nanofibers is able to improve the mechanical durability and maintain the three-dimensional structure of the nanofibrous mats. More importantly, our results indicate that this double-container drug delivery system (both PLGA polymer and MWCNTs are drug carriers) is beneficial to avoid the burst release of the drug and able to release the antitumor drug Dox in a sustained manner for 42 days. The developed composite electrospun nanofibrous drug delivery system may be used as therapeutic scaffold materials for post-operative local chemotherapy.

Increasing use of wearable electronic devices have resulted in enhanced demand for highly flexible supercapacitor electrodes with superior electrochemical performance. In this study, flexible composite membranes with electrosprayed MnO2 particles uniformly anchored on Fe3O4 doped electrospun carbon nanofibers (Fe3O4@CNFMn) have been prepared as flexible electrodes for high-performance supercapacitors. The interconnected porous beaded structure ensures free movement of electrolyte within the composite membranes, therefore, the developed supercapacitor electrodes not only offer high specific capacitance of ~306 F/g, but also exhibit good capacitance retention of ~85% after 2000 cycles, which certify that the synthesized electrodes offer high and stable electrochemical performance. Additionally, the supercapacitors fabricated from our developed electrodes well maintain their performance under flexural stress and exhibit a very minute change in specific capacitance even up to 180° bending angle. The developed electrode fabrication strategy integrating electrospinning and electrospray techniques paves new insights into the development of potential functional nanofibrous materials for light weight and flexible wearable supercapacitors.

47 kinds of woven fabrics were prepared with different fibers, thicknesses, weights per square meter and percentage covers. Statistical analysis method was employed to study the influence of the material and structure parameters on near-infrared transmission of these fabrics. Firstly, the effect of materials on near-infrared transmittance was determined through the contingency table analysis. Then the parameters significantly influencing near-infrared transmittance were found out and correlations among them were discussed by direct correlation and partial correlation analysis. Finally, regression equation of the near-infrared transmittance was established using factor analysis and principal component extraction. Results show that materials have little influence on near-infrared transmittance of woven fabrics. However, thickness, weight per square meter and percentage cover of the fabrics are closely related to near-infrared transmittance. Because there are correlations among thickness, weight per square meter and percentage cover, two new factors are extracted to establish the regression equation. The equation has an error rate of less than 5 % and thus can predict near-infrared transmittance precisely.

Ethanol, as the first coagulation bath, and several common organic solvents, as well as aqueous solutions of NH4Cl, NaHCO3 and NaOH were explored and demonstrated to be adopted as the second coagulation bath for cellulose/phosphoric acid/tetraphosphoric acid (cellulose/complex PA solvent) solution to produce novel cellulose fibers by two-stage dry-wet spinning in a laboratory scale, and effect of coagulants, cellulose concentration, solvent concentration (P2O5 concentration) and coagulation temperature on crystal structure and properties of corresponding fibers were investigated. Surface morphology of regenerated fibers as-spun from different coagulants was observed by scanning electronic microscope (SEM), indicating that methanol and 8 wt% NaOH aqueous solution all rendered cellulose fibers relatively dense and smooth surface. X-ray diffraction (XRD) analysis showed that cellulose fiber precipitated from 8 wt% NaOH aqueous solution had pronounced characteristic peak of cellulose II than those of fibers precipitated from other coagulants, and highest crystallinity and orientation. Meanwhile, those two coagulants referred above also gave cellulose fibers relatively higher tensile strength under the same prerequisite. TGA curves exhibited that fibers were thermally stable produced from two salt aqueous solutions (8 wt% NH4Cl and NaHCO3) since they had the relatively higher onset decomposition temperatures. By evaluating the effect of cellulose concentration, P2O5 concentration and coagulation temperature on the structure and properties of asprepared fibers, it was preferable to produce cellulose fiber from a solution at 20 wt% cellulose concentration, 73 % P2O5 concentration, and coagulating in methanol at coagulation temperature of 60 °C at the second-stage.

Mechanical properties of biodegradable poly(butylene succinate-co-terephthalate) (PBST) fibers with 70 mol% butylene terephthalate (BT) were intensively investigated. Chemical structure composed of hard BT units and soft butylene succinate (BS) units made contributions to the higher elongation at break and lower initial modulus of PBST fibers than poly(butylene terephthalate) (PBT) fibers. Moreover, PBST fibers had better elastic properties than PBT fibers by exploring their elastic recovery. The stretch elastic recovery mechanism of PBST fibers was clarified from the point of crystal structure transition. According to the preliminary studies by wide angle X-ray diffraction (WAXD) measurements, two polymorphs (α form and β form) were confirmed when PBST fibers were applied to different deformations. With the help of intensive study by small angle X-ray scattering (SAXS) measurements, the crystal structure transition of PBST fibers was further verified.

Fabrication of air filtration materials (AFM) that allow air to easily flow through while retaining particles is a significant and urgent need due to the harmful airborne particulate matter pollution; however, this is still a challenging research area. Herein, we report novel slip-effect functional nanofibrous membranes with decreased air resistance (reduction rate of 40%) due to the slip flow of air molecules on the periphery of nanofibers. This was achieved through careful control over the diameters of electrospun polyacrylonitrile fibers and aperture size of fiber assembly. Fiber assembly with 86% of fiber diameters between 60–100 nm was found to be most effective for slip flow, as these diameters are close to the mean free path of air molecules (65.3 nm). Significantly, an equilibrium factor τ = df/d2 has been introduced to elucidate the effect of distance of adjacent fibers on the drag force of airflow. Furthermore, the most effective aperture size (>3.5 μm) for slip-effect has been determined. Ultimately, the new material displayed low air resistance of 29.5 Pa, high purification efficiency of 99.09%, good transmittance of 77%, and long service life. The successful fabrication of such materials can facilitate the development of high-performance AFMs for various applications.

In this paper, studies of the temperature dependence for spherulitic growth of PBST copolyester bearing 70 mol% butylene terephthalate units (named as PBST-70) ranged from 70 to 170 °C were first reported based on the Lauritzen–Hoffman secondary nucleation theory. The results showed that maximum spherulitic growth rate of PBST-70 was obtained under crystallization temperature of 90 °C, and more perfect spherulites were formed via increasing isothermal crystallization temperature by POM measurement. The classical regime I → II and regime II → III transitions occurred at the temperatures of 150 and 110 °C, respectively, using the empirical universal values of U* = 6300 J mol−1 and T ∞ = T g − 30 K. Moreover, the effects of isothermal crystallization temperature on crystal lamellar thickness, thermal and tensile properties of PBST-70 were systematically investigated by small angle X-ray scattering, differential scanning calorimeter, and strength tester. The results indicated that the crystal lamellar thickness increased by increasing isothermal crystallization temperature. The endothermic peak shifted to higher temperature and the tensile properties of PBST-70 were enhanced under higher isothermal crystallization temperature.

Sixty-one and forty-four compounds were identified from the volatile oils of the bast and fibers of Apocynum venetum by means of gas chromatography-mass spectrometry (GC-MS), respectively. The fatty acids, esters, ketones, aldehydes, alkanes, phenols, and miscellaneous compounds were found as the major components in both samples. Furthermore, both of volatile oils exhibited antibacterial properties against Staphylococcus aureus, Staphyloccus epidermidis, and Escherichia coli, whereas they showed weak inhibitory effects on Bacillus lentus and Candida albicans. These results confirmed the claim that A. venetum fibers have antibacterial properties and provide theoretical foundation to make better use of A. venetum fibers.

Natural bamboo fibers have excellent properties suggesting that there is a good potential for them to be used in textiles; however, they have not received the attention that they deserve owing to their coarse and stiff quality. Therefore, a chemical method for extraction and modification of natural bamboo fibers for textile end uses were developed and optimized in this paper. The quality of natural bamboo fibers were characterized by their chemical composition, linear density, and tenacity. Experimental results show that the modified bamboo fibers are finer, with significant lower content of noncellulosic substances. The processing parameters are optimized as: 20 g/l NaOH, 3 g/l Na5P3O10, 5 g/l Na2SO3, 3 g/l penetrating agent, with a fiber to liquid ratio of 1:10, at 100 °C for 2 h, and the bamboo fiber thus produced has cellulose amount of 73.25 %, fineness of 3.26 tex, average length of 44.5 mm, breaking elongation of 2.8 % and tenacity of 2.41 cN/dtex. The result of this study may offer a possibility of developing natural bamboo fibers into practical applications in textiles.

Poly(butylene succinate-co-terephthalate) (PBST) copolyesters, with rigid butylene terephthalate (BT) units varying from 50 to 70 mol%, were synthesized via direct esterification route. The chemical structure and comonomer composition were characterized by 1H NMR. The weight-average molecular weights (Mw) of the prepared products measured by GPC spanned a range of 1.39 × 105–1.93 × 105 with corresponding Mw/Mn value of 2.23–2.42. Based on the WAXD analysis, PBST copolyesters were identified to have the same crystal structure as that of poly(butylene terephthalate) (PBT). The researches on the thermal properties showed that the melting temperature and decomposed temperature of PBST copolyesters increased with the increasing content of rigid BT units through DSC and TGA measurement. Furthermore, the tensile test results presented that the copolyester with higher content of BT units had higher initial modulus, higher breaking strength but lower elongation at break. Additionally, the viscoelastic properties of the prepared PBST films were analyzed by DMA measurement. It was found that both storage modulus (E′) and loss modulus (E″) corresponding to the peak tended to heighten with the increase of BT units, indicating the copolyester with higher BT units content had the more prominent viscoelasticity. The peak of loss factor (tan δ) curve shifted to higher temperature as the content of rigid BT units increased due to the increasing of the glass transition temperature (Tg).

Apocynum venetum (AV) fibers were extracted by the combination of low (28 kHz) and high frequency (53 kHz) ultrasonic treatment after aqueous alkali maceration. The surface impurities and cementing components between fibers in the range of 10–50 µm were removed by low frequency ultrasound. The surface impurities in the range of 2–8 µm, as well as the residuals in the surface depression and inner cavum of fibers were further eliminated by high frequency ultrasonic irradiation. The treatment did not change crystal structure of cellulose I of AV fibers and could lead to a higher degree of crystallinity. Meanwhile, the examination of mechanical properties showed that the AV fibers could be used for textile industry. It is demonstrated that the combination of low and high frequency ultrasound after alkali treatment is simpler, more controllable and more environment-friendly and is a promising degumming method for textile industry.

The composition, structure, physicochemical properties, and optical properties of the raw jute and the treated jute were studied in this work. The results of FT-IR and SEM indicated that both alkali scouring and hydrogen peroxide bleaching exhibited good ability to remove non-cellulose materials, and the results were further confirmed by the composition analysis. Changes in fineness and moisture regain were obviously affected by the degree of non-cellulose removal. The XRD results showed that there was no crystalline transformation of the crystalline structure when the jute was treated under the applied condition. However, the crystallinity index of all the treated samples increased in comparison with the raw jute, which induced the change of mechanical properties. The brightness index and the whiteness index were greatly affected by bleaching rather than alkali scouring. Furthermore, there was a formidable decrease in the yellowness index when the jute was bleached.

Biodegradable copolymer poly(butylene succinate-co-terephthalate) (PBST), with 70 mol% butylene terephthalate (BT), was melt-spun into fibers with take-up velocity of 2 km/min. The mechanical and thermal properties of the as-spun fibers were investigated through tensile test, DSC and TGA. Compared to poly(butylene terephthalate) (PBT) fibers, PBST fibers exhibited lower initial tensile modulus and higher tensile elongation at break which indicated their better flexibility. DSC results showed high melting temperature (ca.180.7 °C) of PBST fibers helpful to the textile processing compared to other biodegradable polyesters. Furthermore, isothermal crystallization behaviors of PBST fibers at low and high supercoolings were investigated by DSC and DLI, respectively. The measurement of crystallization kinetics at low supercoolings indicated that Avrami exponent n for PBST fibers was at a range of 2.9 to 3.3, corresponding to the heterogeneous nucleation and a 3-dimensional spherulitic growth. Similar results were given for isothermal crystallization behavior at high supercoolings investigated by DLI technique. Additionally, the equilibrium melting temperature of PBST fibers was obtained for 206.5 °C by Hoffman-Weeks method. Further investigation through DLI measurement provided the temperature at maximum crystallization rate for PBST fibers located at about 90 °C, which was very useful to polymer processing.

The regenerated cellulose fibers were prepared by wet-spinning from NaOH/thiourea/urea aqueous solvent system for the first time. The effects of coagulation and stretch conditions on the structure, morphology, and mechanical properties of the prepared fibers were investigated by wide-angle X-ray diffraction (WAXD), scanning electron microscope (SEM), and tensile tester, respectively. When the cellulose spinning dope was coagulated in 10% H2SO4/12.5% Na2SO4 aqueous solution at 15 °C, the prepared fibers had a typical crystalline structure of cellulose II and circular cross-sectional shapes with smooth surface and slightly high tensile properties to viscose fibers.

Three-dimensional nanofibrous aerogels (NFAs) that are both highly compressible and resilient would have broad technological implications for areas ranging from electrical devices and bioengineering to damping materials; however, creating such NFAs has proven extremely challenging. Here we report a novel strategy to create fibrous, isotropically bonded elastic reconstructed (FIBER) NFAs with a hierarchical cellular structure and superelasticity by combining electrospun nanofibres and the fibrous freeze-shaping technique. Our approach causes the intrinsically lamellar deposited electrospun nanofibres to assemble into elastic bulk aerogels with tunable densities and desirable shapes on a large scale. The resulting FIBER NFAs exhibit densities of >0.12 mg cm(-3), rapid recovery from deformation, efficient energy absorption and multifunctionality in terms of the combination of thermal insulation, sound absorption, emulsion separation and elasticity-responsive electric conduction. The successful synthesis of such fascinating materials may provide new insights into the design and development of multifunctional NFAs for various applications.

In this paper, a hand-operating method (tiled test method) of the wool-blending sample is made out, and make use of the method, the test of wool-blending bundle in different blending ratio is accomplished. According to the test data, the synthesis method of the stretch curve is worked out and the synthesis software for the typical stretch curve of wool-blending bundle is designed. Through laboratory hand-operating method, the blending fasciculus applying to fiber bundle test can be obtained in a short time. Calculation for sampling is accomplished in the article. We bring up 9 new signs to describe the characteristics of the curve behind peak for the first time: elongation behind peak (HE), elongation percentage behind peak (HEP), relative elongation rate behind peak (RHE), total break work (W a), break work behind peak (HW), break work coefficient behind peak (HWC), elongation percentage of half-load behind peak (HEL), load percentage of half-elongation behind peak (HLE), break efficiency behind peak (HEC).

An allometrical scaling relationship between the diameter of electrospun nanofiber and solution concentration is established, the scaling exponent differs greatly between different polymers and the same polymer with different molecules or the same molecules with different properties. The diameter of electrospun polyacrylonitrile (PAN) nanofibers increases approximately linearly with solution concentration.