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Silver nanoparticles embedded in SiO2 particles of micrometer size are prepared using spray drying. The spray drying is performed with a SiO2 sol (solvent water:ethanol 4 : 1) containing SiO2 and silver particles of nanometer size. During spray drying the SiO2 nanoparticles aggregate to SiO2 microspheres whereas the silver particles exhibit only a small tendency of aggregation and keep their nanometer size. However under special conditions also the formation of crystalline silver rods is observed. The antibacterial activity of the resulting Ag/SiO2 powders is determined against the bacteria Escherichia coli and Bacillus subtilis. Because of this antibacterial acitivity and the fact that the powder of SiO2 microspheres exhibits a good dispersibility, such materials have an immense potential to be used as antimicrobial additive in processes like master batch or fiber production. [ABSTRACT FROM AUTHOR]

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Antimicrobial finished textiles are suitable for a wide range of applications. For instance, they can be advantageous in sportswear, but are also usable for hygienic and medical products. Especially patients suffering from neurodermatitis or diabetes can gain benefits due to a reduced risk for the appearance of secondary infections. An antimicrobial effect can be realized by metal ions from zinc, copper, and silver. An inorganic storage matrix is applied to load the material with these metal ions. Fixation of storage matrices is done by sol-gel-technology. The resulting porous hybrid film allows the ions to diffuse into the surrounding medium. [ABSTRACT FROM AUTHOR]

Microalgae and ground macroalgae can be fixed on fibers and textiles by use of sol-gel coating agents. By this, the biofunctionality of algae can be fixed on textiles and lead to biofunctionalized textiles. Examples for promising application are given in the fields of bioreactors, water treatment and antimicrobial functional textiles. [ABSTRACT FROM AUTHOR]

Common textile materials as cotton or polyester do not possess reliable X-ray absorption properties. This is due to their morphology and chemical composition in particular. Common fibers are built up from organic polymers containing mainly the elements carbon, hydrogen, oxygen and nitrogen. These “light” elements only have low X-ray absorption coefficients. In contrast, inorganic materials composed of “heavy” elements with high atomic numbers, e.g. barium or bismuth, exhibit X-ray absorption coefficients higher by up to two orders of magnitude. To obtain a flexible yarn with high X-ray absorption properties both these materials, the organic polymer and the inorganic X-ray absorber, are combined to an inorganic/organic composite fiber material. Hence, as the organic component cellulose from modified Lyocell-process is used as carrier fiber and blended with inorganic absorber particles of low toxicity and high absorption coefficients, as bariumsulphate, bariumtitanate or bismuthoxide. A content of inorganic absorber particles equally distributed in the whole fiber of up to 20% is achieved. The composite fibers are produced as staple or filament fibers and processed to multifilament or staple fiber yarns. The staple fiber yarns are rotor-spinned to increase the comfort of the subsequent textile material. Several woven fabrics, considering multilayer structure and different warp/weft density, are developed. The energy dependent X-ray shielding properties are determined in dependence on the different yarn compositions, yarn types and structural parameters of the woven fabrics. As a result, a production process of textile materials with comfortable and dedicated X-ray absorption properties is established. It offers a promising opportunity for manufacturing of specialized textiles, working clothes or uniforms applicable for medicine, air craft and security personal, mining as well as for innovative composite materials. [ABSTRACT FROM AUTHOR]

Highlights: [•] Higher silver doping smaller nanoparticles size and weaker agglomeration. [•] Higher silver concentration higher optical absorbance and band gap energy. [•] Small amouts of silver have considerably increased the antimicobial activity. [•] The photocatalytic activity is consistent with the increase of antimicrobial activity. [ABSTRACT FROM AUTHOR]

Abstract: New hybrid nanofibers prepared with chitosan (CTS), containing a total amount of polyethylene oxide (PEO) down to 3.6wt.%, and silica precursors were produced by electrospinning. The solution of modified sol–gel particles contained tetraethoxysilane (TEOS) and the organosilane 3-glycidyloxypropyltriethoxysilane (GPTEOS). This is rending stable solution toward gelation and contributing in covalent bonding with chitosan. The fibers encompass advantages of biocompatible polymer template silicate components to form self-assembled core–shell structure of the polymer CTS/PEO encapsulated by the silica. Potential applicability of this hybrid material to bone tissue engineering was studied examining its cellular compatibility and bioactivity. The nanofiber matrices were proved cytocompatible when seeded with bone-forming 7F2-cells, promoting attachment and proliferation over 7 days. These found to enhance a fast apatite formation by incorporation of Ca2+ ions and subsequent immersion in modified simulated body fluid (m-SBF). The tunable properties of these hybrid nanofibers can find applications as active biomaterials in bone repair and regeneration. [Copyright &y& Elsevier]

Untreated textile effluent may contain toxic organic pollutants that can have negative impacts on the ecosystem. Among the harmful chemicals present in dyeing wastewater, there are two frequently used organic dyes: methylene blue (cationic) and congo red (anionic). The current study presents investigations on a novel two-tier nanocomposite membrane, i.e., a top layer formed of electrosprayed chitosan-graphene oxide and a bottom layer consisting of an ethylene diamine functionalized polyacrylonitrile electrospun nanofiber for the simultaneous removal of the congo red and methylene blue dyes. The fabricated nanocomposite was characterized using FT-IR spectroscopy, scanning electron microscopy, UV-visible spectroscopy, and Drop Shape Analyzer. Isotherm modeling was used to determine the efficiency of dye adsorption for the electrosprayed nanocomposite membrane and the confirmed maximum adsorptive capacities of 182.5 mg/g for congo red and 219.3 mg/g for methylene blue, which fits with the Langmuir isotherm model, suggesting uniform single-layer adsorption. It was also discovered that the adsorbent preferred an acidic pH level for the removal of congo red and a basic pH level for the removal of methylene blue. The gained results can be a first step for the development of new wastewater cleaning techniques.

Textile wastewater accommodates many toxic organic contaminants that could potentially threaten the ecosystem if left untreated. Methylene blue is a toxic, non-biodegradable, cationic dye that is reportedly observed in significant amounts in the textile effluent stream as it is widely used to dye silk and cotton fabrics. Congo red is a carcinogenic anionic dye commonly used in the textile industry. This study reports an investigation of methylene blue and Congo red removal using a chitosan-graphene oxide dip-coated electrospun nanofiber membrane. The fabricated nanocomposite was characterized using Scanning Electron Microscopy (SEM), FT-IR Spectroscopy, Raman Spectroscopy, UV-vis Spectroscopy, Drop Shape Analyzer, and X-ray Diffraction. The isotherm modeling confirmed a maximum adsorptive capacity of 201 mg/g for methylene blue and 152 mg/g for Congo red, which were well fitted with a Langmuir isotherm model indicating homogenous monolayer adsorption.

The article presented concerns the application of fluorescein as a fluorescent material for anti-counterfeiting technology which will allow the labeling and identification of legitimate articles in the textile field. Fluorescein has been applied to polyester fabrics by microwave irradiation technique in the presence of a UV absorber. Thus, its presence in the textile substrate is detectable following an excitation at a specific wavelength belonging to the Ultra-violet zone, which makes this material very effective for tracking and detecting counterfeit articles. Fluorescent samples are characterized morphologically by scanning electron microscopy (SEM) and quantitatively by optical spectroscopy such as reflectance and transmission measurements. The treated samples show under UV light a yellowish green emission with a slight yellow coloration of the polyester fiber. The UV absorber applied to the fluorescent solution improves the light resistance of the treated samples by 25%. Their addition to the bath can also ensure the production of a protective fabric against UV., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Microwave assisted synthesis is a well established method in organic and inorganic chemistry. It is also used in material science to realize novel carbon nanoparticles exhibiting fluorescence properties. The results presented here are related to a microwave driven solvothermal process used for the conversion of amino acid and 1,2-diaminoethane into fluorescent solutions. Arginine, lysine and glycine were used as amino acids. The process temperatures are set in the range of 80° to 140 °C and the maximum process pressure is 4.5 bar. The process duration is set from 5 to 30 minutes. The fluorescence effect is increased with increasing temperature. The prepared aqueous fluorescent solutions can be used as media to induce fluorescence in textile substrates. The current study can be understood as a first proof-of-concept of a very simple microwave-assisted solvothermal synthesis of fluorescent compounds useful for the modification of different substrates.

Silver nanoparticles embedded in SiO2 particles of micrometer size are prepared using spray drying. The spray drying is performed with a SiO2 sol (solvent water:ethanol 4: 1) containing SiO2 and silver particles of nanometer size. During spray drying the SiO2 nanoparticles aggregate to SiO2 microspheres whereas the silver particles exhibit only a small tendency of aggregation and keep their nanometer size. However under special conditions also the formation of crystalline silver rods is observed. The antibacterial activity of the resulting Ag/SiO2 powders is determined against the bacteria Escherichia coli and Bacillus subtilis. Because of this antibacterial acitivity and the fact that the powder of SiO2 microspheres exhibits a good dispersibility, such materials have an immense potential to be used as antimicrobial additive in processes like master batch or fiber production.