Citric Acid Modified Kaolin and Its Application in Polyamide Wet Coating

The ink absorption of polyamide-coated polyamide textile products containing kaolin is poor. Citric acid was used to modify kaolin, and the adsorptive performance of rhodamine B was studied. The modified kaolin with the best adsorptive ability was selected. The results showed that kaolin modified with a 2.0 M citric acid solution was strongly adsorptive. During the interaction between citric acid and kaolin, H+ acts on the surface and interlayer of kaolin, and on Al3+ and Si4+ in the kaolin. This results in an increase in the specific surface area and a smaller particle size. After using modified kaolin in the polyamide wet coating, the ink-absorption of polyamide-coated polyamide fabrics improved and the resulting pH value met Oeko-Tex Standard 100 requirements for textile use.

Study of the Change of the Specialists' Isolative Garment Properties Against the Effects of Peroxide Decontamination Mixture

The influence of the peroxide decontamination mixture on the barrier polymeric material used for the construction of the anti-gas protective garment OPCH-05 has been study. This kind of mixture is used with the help of the decontamination vehicle ACHR-90 and its EDS mixture. The both soldiers and operators of the ACHR-90 or the EDS mixture can be in a direct contact with spattering decontamination mixture that can cause significant damages of the anti-gas protective garment OPCH-05. For evaluation of protective properties and their potential changes the MIKROTEST method and methodology has been used. This paper is another publication which deals with the influences of decontamination mixtures introduced in the Czech Armed Forces Chemical Corps armament on the barrier material composed of the butyl-rubber polymeric mixture in combination with the polyamide textile.

Ambulatory Evaluation of ECG Signals Obtained Using Washable Textile-Based Electrodes Made with Chemically Modified PEDOT:PSS

A development of washable PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) polyamide textile-based electrodes is an interesting alternative to the traditional Ag/AgCl disposable electrodes, usually used in clinical practice, helping to improve medical assessment and treatment before apparition or progress of patients’ cardiovascular symptoms. This study was conducted in order to determine whether physical properties of PEDOT:PSS had a significant impact on the coated electrode’s electrocardiogram (ECG) signal quality, particularly after 50 washing cycles in a domestic laundry machine. Tests performed, included the comparison of two PEDOT:PSS solutions, in term of viscosity with emphasis on wetting tests, including surface tension and contact angle measurements. In addition, polyamide textile fabrics were used as substrate to make thirty electrodes and to characterize the amount of PEDOT:PSS absorbed as a function of time. The results showed that surface tension of PEDOT:PSS had a significant impact on the wetting of polyamide textile fabric and consequently on the absorbed amount. In fact, lower values of surface tension of the solution lead to low values contact angles between PEDOT:PSS and textile fabric (good wettability). Before washing, no significant difference has been observed among signal-to-noise ratios measured (SNR) for coated electrodes by the two PEDOT:PSS solutions. However, after 50 washing cycles, SNR decreased strongly for electrodes coated by the solution that had low viscosity, since it contained less solid contents. That was confirmed by scanning electron microscopy images (SEM) and also by analyzing the color change of electrodes based on the calculation of CIELAB color space coordinates. Moreover, spectral power density of recorded ECG signals has been computed and presented. All cardiac waves were still visible in the ECG signals after 50 washing cycles. Furthermore, an experienced cardiologist considered that all the ECG signals acquired were acceptable. Accordingly, our newly developed polyamide textile-based electrodes seem to be suitable for long-term monitoring. The study also provided new insights into the better choice of PEDOT:PSS formulation as a function of a specific process in order to manufacture cheaper electrodes faster.

Multifunctional finishing treatments applied on textiles for protection of emergency personnel

The paper presents the results of the researches carried out for obtaining multifunctional textile materials with multiple effects, by means of superior finishing techniques, using functional chemicals in the form of aqueous dispersions. It has been studied the possibility of combining treatment with dispersions with photocatalytic and antibacterial effects with a hydrophobic/oleophobic treatment that simultaneously provides both sustainable photocatalytic and antibacterial effect as well as hydrophobic/oleophobic effect within satisfactory limits for all these effects. The results of the laboratory evaluations performed on 50% cotton and 50% functionalised HT polyamide textile fabrics showed that hydrophobization treatment with fluoropolymer dispersions can be combined with the treatment with titanium dioxide photocalatytic dispersions or silver chloride and titanium dioxide dispersions to obtain multiple photocatalytic, antibacterial and hydrophobic/ oleophobic effects without diminishing the functionalization effects that would have been achieved by individual treatments