Polyvinylidene Fluoride (PVDF) nanofibers were electrospun by Nanospider equipment with wire electrodes. The parameters which would influence the fiber diameter were investigated in terms of solution concentration, cartridge speed (feed rate of solution), voltage, electrode distance, rotating wire speed, winding speed and slit diameter. The morphology and diameter of fibers were observed by scanning electron microscope. The results revealed that the solution concentration had significant influence on both fiber morphology and fiber diameter; the cartridge speed, voltage, electrode distance and slit diameter had slight effect on fiber diameter since the standard deviations were large; the rotating wire speed and the winding speed had insignificant influence on fiber diameter.

Air permeability is a very important property influencing the performance of clothing comfort and technical textiles particularly in applications for protective products, including airbags, parachutes, and tents. Several analytical models for predicting air permeability have been made by considering porosity and pore diameter or porous area. However, the connection between fabric structure and air permeability with analytical models has not been well reported as yet. In this work, the diameter of cotton yarn was predicted by considering yarn count, twist, and packing density. Subsequently, the pore area and equivalent pore diameter of fabric were predicted after finding the warp and the weft densities of fabric. The predicted values had very good agreement with the experimental results in yarn diameter and other structural parameters of fabric. The air permeability of fabrics was measured and several well-known analytical models for predicting air permeability were compared. The results revealed that the Hagen–Poiseuille equation had much better prediction than other models and also had good agreement with the experimental results, especially when it was applied for tight fabrics at low pressure drop (≤60 Pa). The Hagen–Poiseuille equation could be improved by considering the Reynolds number, interfiber interstices, and the deformation of pores under higher pressure drop.

COVID-19, classified as SARS-CoV-2, is causing an ongoing global pandemic. The pandemic has resulted in the loss of lives and has caused economic hardships. Most of the devices used to protect against the transmission of the novel COVID-19 disease are related to textile structures. Hence, the challenge for textile professionals is to design and develop suitable textile structures with multiple functionalities for capturing viruses, passivating them, and, at the same time, having no adverse effects on humans during the complete period of use. In addition to manufacturing efficient, biocompatible, and cost-effective protective face masks, it is also necessary to inform the public about the benefits and risks of protective face mask materials. The purpose of this article is to address the concerns of efficiency and efficacy of face masks by primarily reviewing the literature of research conducted at the Technical University of Liberec. The main focus is on the presentation of problems related to the specification of aims of face mask applications, mechanisms of capture, durability, and modes of sterilization. The recommendations, instead of conclusions, are addressed to the whole textile society because they should be leading players in the design, creation, and proper treatment of face masks due to their familiarity with the complex behavior of textile structures and targeted changes of structural hierarchy starting from polymeric chains (nano-level) and ending in planar textile structures (millimeter level) due to action by mechanical, physical and chemical fields. This becomes extremely critical to saving hundreds of thousands of lives from COVID-19.

Two types of microencapsulated phase change materials (ENPCMs) were synthesized by polymerization. The core material of ENPCM was n-octadecane and the shell materials were polymethyl methacrylate-butyl acrylate and polymethyl methacrylate-butyl acrylate-hydroxyethyl methacrylate. Subsequently, the synthesized ENPCMs were applied onto bamboo fabric by the dip and dry method. The properties of ENPCMs were analyzed in terms of surface morphology, size distribution and latent heat; the treated bamboo fabrics were evaluated in terms of surface morphology, hydrophilicity, washing fastness and heat storage capacity. The results showed that polymethyl methacrylate-butyl acrylate/n-octadecane (PMBO) microcapsules had an irregular shape, while polymethyl methacrylate-butyl acrylate-hydroxyethyl methacrylate/n-octadecane (PMBHO) microcapsules were spherical, and the mean diameters of both microcapsules were less than 1 µm. The latent heat of phase change material (PCM) microcapsules was almost the same at a thermal storage capacity of 110 J/g. There were many more and more even PMBHO microcapsules deposited on bamboo fabric than that of PMBO microcapsules deposited on bamboo fabric. Bamboo fabrics treated by both microcapsules were hydrophilic, and the hydrophilicity of fabric treated by PMBHO microcapsules was even better. The ratio of PCM microcapsules to bamboo fabric was about 1:4, and the latent heat of treated bamboo fabrics was about 20 J/g. Moreover, the treated bamboo fabrics exhibited excellent washing fastness due to the strong binding strength between the highly hydrophilic microcapsules and bamboo fibers. Approximately 72% of PCM microcapsules were retained on the fabric after 15 washing cycles.

High thermostability of phase change materials is the critical factor for producing phase change thermoregulated fiber (PCTF) by melt spinning. To achieve the production of PCTF from melt spinning, a composite phase change material with high thermostability was developed, and a sheath-core structure of PCTF was also developed from bicomponent melt spinning. The sheath layer was polyamide 6, and the core layer was made from a composite of polyethylene and paraffin. The PCTF was characterized by scanning electron microscopy (SEM), thermal analysis (TG), Fourier Transform Infra-Red (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and fiber strength tester. The results showed that the core material had a very high thermostability at a volatilization temperature of 235 °C, the PCTF had an endothermic and exothermic process in the temperature range of 20–30 °C, and the maximum latent heat of the PCTF reached 20.11 J/g. The tenacity of the PCTF gradually decreased and then reached a stable state with the increase of temperature from −25 °C to 80 °C. The PCTF had a tenacity of 343.59 MPa at 0 °C, and of 254.63 MPa at 25 °C, which fully meets the application requirements of fiber in textiles.