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The static simulation of weft knitting can be efficiently realized by graphics simulation techniques, but there still remains a challenge for mechanical models. The lack of practical mechanical models significantly limit the realistic deformation behaviors of complex cable stitches, which lead to a great different between the simulation effect and the actual fabric. In order to obtain the deformation behavior and volumetric performance of cable stitch, loop models were built based on an improved particle system in this work. Compared with plain weft knitted, the offset value of bonding points of cable stitches were measured. By analyzing the relationship between the deformation of loops and the displacement of the particles, the deformation behavior of cable stitch was simulated. Velocity-Verlet integration was introduced to simulate cable stitches and the stable results were obtained. The results show that these models and algorithm displayed the accurate deformation behavior of cable stitches, as demonstrated by qualitative comparisons to measure the deformations of actual samples.

Towards the goal of developing anti-infective textiles based on a photodynamic inactivation mechanism, here we present the design, dyeing procedure, characterization, substrate photooxidation studies, and antibacterial efficacy of methylene blue-dyed polyester fabrics, termed MB-polyester. Dye-uptake and apparent K/S (absorption and scattering coefficient) values as a function of MB concentration % (o.w.f) were determined, and were found to correlate. Photooxidation studies employing the model substrate 1,5-dihydroxynaphthalene (1,5-DHN) revealed that the MB-polyester fabrics were able to generate singlet oxygen in an illumination time-dependent manner. Antibacterial efficacy was evaluated against Staphylococcus aureus (ATCC-29213), with our best results achieving a 99.89 % (~3 log units) reduction in Colony-Forming Units (CFU)/mL after only 30 min illumination (Xenon lamp, 3500 mW/cm2, 420–780 nm). On the basis of these results with MB-polyester, we subsequently designed patterned dual-dyed polyester/cotton fabrics, wherein an alternating pattern of MBdyed polyester was combined with direct dyes-dyed cotton, and showed that their ability to sensitize singlet oxygen (1O2) in the photooxidation reaction of 1,5-DHN was maintained. Taken together, these findings suggest that MB is a suitable photosensitizer (PS) against S. aureus for the practical development of low-cost polyester-based antimicrobial textiles, and can potentially be used in the production of diverse form-patterned textiles that possess a photodynamic antimicrobial inactivation mechanism.

A novel graphene oxide/polyester (GO/PET) composite fabric as a recyclable adsorbent was prepared via electrostatic self-assembly. The structure, morphology, and properties of the GO/PET composite fabrics were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), Fourier transformed infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and contact angle (CA), respectively. The absorption property was evaluated by the absorption amount and removal efficiency of methylene blue (MB) solution on the GO/PET composite fabric. The results indicated that the absorption amount was found to be 21.80 mg/g and the removal efficiency reached 99.93 % under the experimental conditions of GO concentration of 2 mg/ml, initial concentration of 50 mg/l, and area of 64 cm2. The experimental parameters were investigated including the concentration of GO, the initial concentration of MB solutions, and adsorbent area. Simultaneously, according to a series of dynamic analysis, the absorption process revealed that the kinetics was well-described by pseudo-second-order model. This study showed that the GO/PET composite fabric could be a recyclable, efficient adsorbent material for the environmental cleanup.

Melt-electrospinning is an efficient and environmental-friendly technique for producing nano/micro fibers. In this work, the self-layering behavior of poly(ethylene terephthalate)(PET) fiber deposition during melt-electrospinning was investigated based on the electric field simulation analysis by ANSYS and high voltage insulation theory of capacitor for melt-electrospinning configuration. The simulation results demonstrated that during melt-electrospinning process, the electric field strength on the center and lateral surface of the collector changed alternately when some electrically charged jet deposited, making jet depositing location moved around between center and lateral surface, resulted in the formation of the binding fibers separating the inner and outer layers in the deposited PET fiber web. The PET fiber web electrospun in 90 minutes could be laminated freely into thirteen layers. The geometric dimensions of these layers were measured and their morphologies were observed by scanning electron microscopy (SEM). These laminated layers were concentric with almost linearly increasing radius from the inner to the outer. Inner layers featured themselves with appearance of thick center and thin edge, while for outer layers, they presented the appearance of thin center and thick edge. The fibers in the web were quite uniformly and had diameters of about 2 μm.

Porous cellulose acetate (CA) films by breath figure (BF) incorporated with capric acid as form-stable phase change materials (PCMs) were fabricated and characterized for storing and retrieving thermal energy. Effects of different solvents, CA concentration and film thickness on morphology, microstructure and thermal energy storage property of formstable PCMs were investigated by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area analyzer and differential scanning calorimetry (DSC), respectively. The results indicated that the prepared CA films were porous with DMF, acetone, and dichloromethane (DCM) as the solvents, and capric acid absorption capacity was as high as 86.9, 75.0 and 82.2 % with the specific surface area of 4.8, 2.8 and 1.8 m2/g. Moreover, porous CA film with 5 % CA concentration and 0.5 mm thickness prepared by using DMF as solvent had larger specific surface area and higher thermal energy storage properties. The fabricated form-stable PCMs could well maintain their PCM characteristics and demonstrated great temperature regulation ability and had potential applications in building energy conservation.

Biocompatible polyvinyl alcohol (PVA)-styrylpyridinium (SbQ)/β-cyclodextrin (β-CD) composite nanofibers were obtained by electrospinning in this study. PVA-SbQ was used as the foundation polymer as well as crosslinking agent, β-CD was incorporated to achieve expected properties such as improved mechanical properties and thermal stability. The Fourier transform infrared spectroscopy (FTIR) spectra confirmed the existence of β-CD, and the morphologies and average fiber diameters of the electrospun composite nanofibers were also analyzed by SEM. X-ray diffraction patterns (XRD) of PVA-SbQ/β-CD composite nanofibers revealed that the inclusion of β-CD in the nanofibers affected the ordered phase of PVA. Besides, the thermal analyses revealed the improvement in the thermal properties for PVA-SbQ/β-CD composite nanofibers. It was found that the crosslinked composite nanofibers showed a clear higher tensile strength (TS) as well as a greater elongation at break (EB). Eventually, antifungal drug griseofulvin (GSV) has been loaded into the composite nanofibers by formation of its inclusion complex with β-CD in aqueous solution, ultraviolet light (UV-Vis) spectral analysis showed that the drug-loading nanofibers had certain sustained release effect.

Polyacrylonitrile (PAN) oriented nanofibers were produced by homemade needleless electrospinning device. Spiral coils were adopted to replace the traditional spinning needles in this equipment. The tracks of multi-jets were controlled by adjusting the microcurrent during the eletrospinning process. The microcurrent value and the motion track of the spinning jet during the spinning process were observed, the fiber morphology and the mechanical properties of fiber membranes were measured. The results revealed that the average diameters of the electrospun fibers were increased from 490 nm to 740 nm. with the addition of organic salt. Meanwhile, the self-clustering phenomenon was obviously observed, and the mechanical properties of obtained fibers were also altered, the tensile strength was improved from 3.63 MPa to 23.90 MPa, while the strain decreased from 74.6 % to 27.1 %.

Coaxial electrospinning is an effective method to produce core-shell nanofibers, which is associated closely with the morphological stability of Taylor cone. However, the nozzle structure mainly influences the formation of Taylor cone during the coaxial electrospinning procedure. In the present work, since the numerical simulation is a novel and convenience method in the theoretical research of the coaxial electrospinning, the influence of different coaxial composite nozzle structures on Taylor cone shape was studied by ANSYS finite element simulation method. Different coaxial composite nozzle structures — concave type, flush type and convex type, were designed in this work. 2D electric field model of the nozzle structures was simulated by utilizing ANSYS finite element analysis software. The simulation results indicated that electric field intensity distribution of concave type nozzle structure was more uniform than those of the other two types. Therefore, a more stable coaxial Taylor cone was formed in the tip of concave type nozzle structure. To verify the accuracy of the simulation results, core-shell nanofibers were spun by using different coaxial composite nozzle structures. In each experiment, PAN and PVP were employed to be the shell and core solution respectively. Besides that high-speed camera was employed to monitor the coaxial electrospinning procedure. The cross-section morphology of electrospun nanofibers was characterized by scanning electron microscope (SEM). The experimental results showed that when the concave type nozzle was used in the coaxial electrospinning process, Taylor Cone morphology was more stable than other type coaxial composite nozzle structures. The cross-section morphology of electrospun fibers observed by SEM revealed that the high stability in core-shell structure also occurred in coaxial electrospinning by using concave nozzle structure. Furthermore, the simulation and experimental results verified the concave type nozzle is the better nozzle structure for coaxial electrospinning to form stable coaxial Taylor cone.

The physicochemical performance of meta-aramid fiber blends treated in supercritical carbon dioxide fluid was studied at different temperatures. The effects of treatment temperatures on the surface morphology, wettability, chemical and crystal structures, thermal and antistatic properties were investigated by employing Scanning electron microscopy, Dynamic wetting measurements, Fourier transform infrared spectrometry, X-ray diffraction, Thermal analysis and Static half period method, respectively. The result showed that the surface of the treated meta-aramid fiber blends was changed with the treatment temperature increasing and more mild grooves and stripes appeared. The dynamic wetting measurements showed that the water contact angles and absorption time for treated fibers were decreased with temperature increasing. The slight shifts of the characteristic bands of the treated meta-aramid fiber blends were observed in FT-IR spectra with the system temperature increasing. Meanwhile, XRD analysis showed that the diffraction intensities of treated samples were improved in the supercritical carbon dioxide fluid because some re-arrangements and re-crystallizations of the molecule chains generated. TG-DTG analysis indicated that the thermal property of meta-aramid fiber blends could be improved at various temperatures. In addition, supercritical carbon dioxide fluid had little negative influence on the physical and antistatic properties of the meta-aramid fiber blends.

Porous carbon/Cobalt (C/Co), carbon/Nickel (C/Ni) and carbon/Copper (C/Cu) nanocomposites were prepared by electrospinning and subsequent carbonization processes at 800 °C in N2 atmosphere. Polymer solutions of polyacrylonitrile/Cobalt acetate (PAN/Co(OAc)2), polyacrylonitrile/Nickel acetate (Ni(OAc)2) and polyacrylonitrile/Copper acetate (Cu(OAc)2) were used as the porous nanocomposites precursors, respectively. It was found that C/Co, C/Ni and C/Cu nanocomposites with diameters of 147 nm were successfully fabricated. X-ray diffraction was used to confirm the presence of metal particles in the nanocomposites. The Brunauer-Emmett-Teller analysis revealed that nanocomposites possess larger specific surface area than that of the carbon nanofibers (C). The electrochemical properties were investigated by cyclic voltammetry (CV) and galvanostatic charge-discharge tests. The C/Cu nanocomposite exhibited an energy density of 2.7Whkg−1, power density of 518 Wkg−1, and a specific capacitance of about 183 Fg−1 at a current density of 1 Ag−1.

Porous nanocomposites are prepared by electrospinning blended polyacrylonitrile, copper acetate and mutiwalled carbon nanotube in N, N-dimethylformamide. The electrospun nanofiber webs are oxidatively stabilized and then carbonized resulting in composite carbon nanofibers. The study reveals that composite nanofibers with relatively smooth surface morphology are successfully prepared. X-ray diffraction is used to confirm the presence of Cu in carbon nanofibers. The carbon nanofibers with CNTs have better thermal stability and higher electrical conductivity. The Brunauer-Emmett-Teller analysis reveals that C/Cu/CNTs nanocomposites with mesopores possess larger specific surface area and narrower pore size distribution than that of C/Cu nanofibers. The electrochemical properties are investigated by cyclic voltammetry and galvanostatic charge-discharge tests. The nanocomposite with 0.5 wt.% CNT loading exhibits an energy density of 2 Whkg−1, power density of 1916 Wkg−1, a specific capacitance of about 225 Fg−1 at a current density of 2 Ag−1 and its capacitance decreased to 78 % of its initial value after 3,000 cycles.

A novel approach to preparing multifunctional composite nanofibrous membrane was developed. Polyacrylonitrile (PAN) nanofibrous membrane was fabricated by electrospinning and then the nitrile groups in PAN copolymer was chemically modified to obtain amidoxime modified PAN (AOPAN) nanofiber membrane which was further used as a functional support for laccase immobilization. During the process of reactive dye degradation catalyzed by the AOPAN nanofiber membrane immobilized with laccase, metal ion adsorption occurred at the same time. The chemical modification was confirmed by Fourier transform spectroscopy (FTIR). Scanning electron microscope (SEM) was employed to investigate the surface morphologies of the electrospun nanofibers before and after laccase immobilization. The effects of environmental factors on laccase activity were studied in detail. It was found that the optimum pH and temperature for the activity of immobilized laccase was 3.5 and 50 °C. The relative activity retention of the immobilized laccase decreased dramatically during the initial four repeated uses. After 20 days’ storage, the activity retention of immobilized laccase was still high above 60 %. It has also proved that laccase immobilized on AOPAN nanofiber membrane performed well in dye degradation and metal ion adsorption.

In the present work, polyamide6-room temperature ionic liquid (PA6-RTIL) composite nanofibers and membranes were successfully prepared for the first time by an electrospinning technique. The surface morphology, component analysis, mechanical properties, thermal properties and conductivity of the PA6-RTIL composite membranes were investigated by field-emission scanning electron microscope (FE-SEM), fourier transform infrared spectrometer (FT-IR), tensile testing, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and digit multimeter, respectively. The morphology, fiber diameter, mechanical strength of the obtained fibers can be controlled by changing experimental parameters for electrospinning, especially the content of RTIL in original electrospun mixture solution. The composite fibrous membranes showed ideal mechanical properties and significantly enhanced conductivity, which may be attributed to intrinsic high mechanical strength of PA6 and conductivity of RTIL.

The four binary fatty acid eutectics of capric-lauric acid (CA-LA), capric-myristic acid (CA-MA), capric-palmitic acid (CA-PA), and capric-stearic acid (CA-SA) were firstly prepared as solid-liquid phase change materials (PCMs); then, the composite phase change nanofibers consisting of CA-based binary fatty acid eutectic and polyethylene terephthalate (PET) were fabricated by electrospinning for thermal energy storage. The maximum mass ratios of fatty acid eutectics versus PET in the nanofibers could reach up to 2/1. The FE-SEM images revealed that the composite nanofibers possessed smooth and cylindrical morphological structure having diameters of about 100–300 nm. The fatty acid eutectic could be uniformly distributed in the three-dimension network structure of the PET nanofibers. The FT-IR results indicated that the fatty acid eutectic and PET had no chemical reaction and exhibited good compatibility with each other. The DSC measurements showed that the prepared composite nanofibers had appropriate phase transition temperatures (about 5–38 °C) based upon climatic requirement, whilst the phase change temperatures and the enthalpy values of the composite nanofibers could be adjusted by changing the contents and the types of binary fatty acid eutectics in the nanofibers. The TGA results suggested that the onset thermal degradation temperatures and charred residues at 700 °C of the composite nanofibers were lower than those of pure PET nanofibers, but higher than those of fatty acid eutectic, which were caused by the fact that the PET had better thermal stability than fatty acid eutectic.

The ultrafine composite fibers consisting of lauric acid (LA) and polyamide 6 (PA6) as form-stable phase change materials (PCMs), were prepared successfully by electrospinning. The effect of carbon nanotubes (CNTs) on the structural morphology, phase change behaviors, thermal stability, flammability and thermal conductivity properties of electrospun LA/ PA6 composite fibers was investigated by field-emission scanning electron microscopy (FE-SEM), differential scanning calorimetry (DSC), thermogravimetric analyses (TGA), microscale combustion calorimeter (MCC) and melting/freezing times measurements, respectively. SEM observations indicated that the LA/PA6 and LA/PA6/CNTs composite fibers possessed flat and ribbon-shaped morphologies, but the neat PA6 fibers had cylindrical shape with smooth surface; and the average fiber diameters for LA/PA6 composite fibers decreased generally with the addition of CNTs. DSC measurements indicated that the heat enthalpies of the composite fibers were lower that that of neat LA powders, while the amounts of CNTs had no appreciable effect on the phase change temperatures and heat enthalpies of the composite fibers. TGA results showed that the addition of CNTs increased the onset thermal degradation temperature, maximum weight loss temperature and charred residue at 700 o C of the composite fibers, attributed to the improved thermal stability properties. It could be found from MCC tests that there were two-step combustion processes for composite fibers, and corresponded respectively to combustion of LA and polymer chains (PA6) in composite fibers. The addition of CNTs reduced the peak of heat release rate (PHRR) of electrospun composite fibers, contributing to the decreased flammability properties. The improved thermal conductivity performances of LA/PA6/CNTs composite fibers was also confirmed by comparing the melting/freezing times of LA/PA6 composite fibers with that of neat LA powders. The results from the SEM observation showed that the composite fibers had no appreciable variations in shape and diameter after heating/cooling processes.

On the basis of previous studies, the structural model of 3-D hollow integrated sandwich composites for the compressive analysis was built by using the finite element software ANSYS. In the paper, the influence of pile height (6, 8 and 10 mm), pile density (4, 6 and 8 mm), elastic modulus (36, 38 and 40 GPa) and poisson ratio (0.30, 0.35 and 0.40) of the 3-D composites on the compressive properties were studied, and the effects of these factors were analyzed and discussed. The results revealed that the maximum value of the stress appeared in the interface between the piles and the face-sheets when the 3-D composites were subject to compressive loads, in which the composites damaged easily. The compressive properties of the 3-D composites increased with the increase of the pile density and poisson ratio, and decreased with that of the pile height. Elastic modulus has little influence on the compressive properties of the 3-D composites. The study provides a reference for the structural optimum of the 3-D composites.

Ployacrylonitrile (PAN) nanofibers were formed by electrospinning. Amidoxime ployacrylonitrile (AOPAN) nanofibers were prepared by reaction with hydroxylamine hydrochloride, which were used as the matrix for metal ions chelation. FTIR spectra of the PAN nanofibers and AOPAN nanofibers were recorded for analysis of the surface chemical structures. The AOPAN conventional fibers were also prepared for comparison, and surface morphologies of the modified PAN conventional fibers and PAN nanofibers were observed by FESEM. Metal ions concentrations were calculated by AAS. The chelated isothermal process and kinetics parameters of the modified PAN nanofibers and PAN conventional fibers were studied in this work. Results indicated that the saturated coordinate capacity of AOPAN nanofibers to Cu2+, Cd2+ was 3.4482 and 4.5408 mmol/g (dry fiber) respectively, nearly two times higher than that of AOPAN conventional fibers. Besides, the desorption rate of Cu2+ and Cd2+ from metal chelated AOPAN nanofibers was 87 and 92 % respectively in 1 mol/l nitric acid solution for 60 min. The isothermal processes were found to be in conformity with Langmuir model.

In this study, the surface functionalization of polyacrylonitrile (PAN) fibers was achieved by depositing ZnO nanoparticles using thermal solvent coating. surface morphology, crystalline structure, surface chemistry, thermal stability and washing stability of the ZnO coated PAN fibers were investigated by scanning electron microscope (SEM), X-ray diffractometer (XRD), Fourier transform Infra red spectroscopy (FT-IR), Thermo-gravimetric analyses (TGA) and washing stability test, respectively. In addition, the weight changes after coating and washing were studied at different coating and washing conditions. The SEM images revealed that the ZnO was well coated on the surface of the PAN fibers and the coating was obviously affected by the experimental temperature. The FT-IR spectra indicated the chemical features of the deposited ZnO nanostructures. The XRD patterns showed that there was a typical crystalline structure of ZnO nanogains formed on the PAN fibers after coating. The TGA results revealed that the thermal stability of the PAN fibers was improved by the ZnO coating. The experimental results of washing stability revealed the effect of temperature on the washing stability. Weight measurements indicated that the amount of ZnO deposited on PAN fibers increased with the increasing of coating temperature from 60 to 70 °C. Weight measurements also revealed that the weight of the ZnO coating on fibers decreased with the increase in washing temperature and washing time.

Nanostructured silver thin films were sputtered onto the aromatic thermotropic liquid crystalline fibers of Vectran by magnetron sputtering technology. Plasma treatment was used as pre-treatment in order to improve the deposition of the coating layer. Surface morphology of the coated fibers was examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). A full energy dispersive X-ray analysis (EDX) was used to detect the elemental composition of the material. Its conductivity and mechanical properties were measured and analyzed as well. The study revealed that a very thin conductive silver deposition exhibited high electrical conductivity as well as less influence on the mechanical properties of the pre-treated Vectran fiber. The plasma treatment could improved the deposition of the coating layer, but the surface roughness caused by plasma treatment also affected the surface conductivity. It was found that the surface resistivity could reach very low value of 1.66×10−3 Ω·cm after sputtering deposition for 30 min.

The Fe-montmorillonite (Fe-MMT) combined catalysis effects of Fe ion with barrier effects of silicate clays, was firstly synthesized by hydrothermal method, and then was modified by cetyltrimethyl ammonium bromide (CTAB). The organic-modified Fe-montmorillonite (Fe-OMT) was dispersed in the N, N-dimethyl formamide (DMF) and then compounded with polyacrylonitrile (PAN) solution which was dissolved in DMF. The composite solutions were electrospun to form PAN/Fe-OMT nanocomposite fibers. The influences of the Fe-OMT on the structure, morphology, thermal, flammability and mechanical properties of PAN nanocomposite fibers were respectively characterized by X-ray diffraction (XRD), High-resolution transmission electron microscopy (HRTEM), Scanning electron microscopy (SEM), Thermogravimetric analyses (TGA), Micro Combustion Calorimeter (MCC) and Electronic Single Yarn Strength Tester. It was found from XRD curves that there was not observable diffraction peak of silicate clay, indicating that the silicate clay layers were well dispersed within the PAN nanofibers. The HRTEM image indicated that the multilayer stacks of nanoclays could be found within the nanofibers and were aligned almost along the axis of the nanofibers. The SEM images showed that the diameters of nanocomposite fibers were decreased with the loading of the Fe-OMT. The TGA analyses revealed that the onset temperature of thermal degradation and charred residue at 700°C of PAN nanocomposite fibers were notably increased compared with the pure PAN nanofibers, contributing to the improved thermal stability properties. It was also observed from MCC analyses that the decreased peak of heat release rate (PHRR) of the PAN nanocomposite fibers reduced the flammability properties. The loadings of Fe-OMT increased the tensile strength of PAN nanocomposite fibers, but the elongation at break of PAN nanocomposite fibers was lower than that of the PAN nanofibers.

In this paper, magnetron sputtering was applied to deposit nano-structured silver films on the surfaces of polylactic acid (PLA) nonwovens, which were used in medical dressings. The influence of the coating thickness of the nano-structured sliver films on the antibacterial property of the nonwovens was studied. The antibacterial properties of the medical dressings were measured by shake flask test. The surface morphology of nano-structured silver films and the grain sizes of silver agglomerates were analyzed by atomic force microscope (AFM). Energy dispersive X-ray (EDX) was employed to analyze the surface elemental compositions. The study revealed that the antibacterial properties were improved as the film thickness increased. AFM images of the coated samples indicated that as the sputtering time prolonged, the film thickness was increased, the film became compacter, and the specific area of the film was also increased. Thus, the release rate of silver ions increased, leading to the improved antibacterial property. It was found that the reduction percentage of both tested bacteria-Staphylococcus aureus and Escherichia coli reached 100 % as the coating thickness exceeded 1 nm.