Plant-Assisted Synthesis of Ag-Based Nanoparticles on Cotton: Antimicrobial and Cytotoxicity Studies.

The syntheses of Ag-based nanoparticles (NPs) with the assistance of plant extracts have been shown to be environmentally benign and cost-effective alternatives to conventional chemical syntheses. This study discusses the application of Paliurus spina-christi, Juglans regia, Humulus lupulus, and Sambucus nigra leaf extracts for in situ synthesis of Ag-based NPs on cotton fabric modified with citric acid. The presence of NPs with an average size ranging from 57 to 99 nm on the fiber surface was confirmed by FESEM. XPS analysis indicated that metallic (Ag0) and/or ionic silver (Ag2O and AgO) appeared on the surface of the modified cotton. The chemical composition, size, shape, and amounts of synthesized NPs were strongly dependent on the applied plant extract. All fabricated nanocomposites exhibited excellent antifungal activity against yeast Candida albicans. Antibacterial activity was significantly stronger against Gram-positive bacteria Staphylococcus aureus than Gram-negative bacteria Escherichia coli. In addition, 99% of silver was retained on the samples after 24 h of contact with physiological saline solution, implying a high stability of nanoparticles. Cytotoxic activity towards HaCaT and MRC5 cells was only observed for the sample synthetized in the presence of H. lupulus extract. Excellent antimicrobial activity and non-cytotoxicity make the developed composites efficient candidates for medicinal applications.

Eco-friendly dyeing of polyamide and polyamide-elastane knits with living bacterial cultures of two Streptomyces sp. strains.

Given the environmental burden of textile industry, especially of dyeing processes and the volume of synthetic dyes and surfactants, the intensive development of the greener approaches is under way. Herein, an environmentaly-friendly dyeing of polyamide (PA) and PA/Elastane (PA/EA) knits using live bacterial approach in water environment, completely eliminating usage of textile auxiliaries is described. A total of 12 pigment-producing Streptomyces strains were isolated and purified from soil and rizoshere or bark of smoke tree Cotinus coggygria samples. The antibacterial, antifungal and cytotoxic effects of crude bacterial extracts were tested. Antimicrobial effect was obtained by the majority of extracts but only two streptomycetes extracts, 11-5 and BPS51, showed moderate cytotoxicity against HaCaT human cell line. This was the reason to select 11-5 and BPS51 strains for the dyeing of the textile materials. Excellent properties of dyeing wool, silk and PA are achieved initially using live cultures, and the bioprocess is optimized on commercial PA and PA/EA knits used for stockings production. Satisfactory coloration of both knits is achieved with dynamic conditions (culture shaking at 180 rpm over 5-14 days at 30 ºC) giving the best coloration results, except in the case of the PA sample dyed with a bacterial strain 11-5. The prolongation of dyeing time leads to higher color yields independently of fabric and bacteria strain. Although the color differences between the samples before and after washing are observed, washing fastness after three washing cycles can be considered as satisfactory.

Antibacterial Bio-Nanocomposite Textile Material Produced from Natural Resources.

Growing demand for sustainable and green technologies has turned industries and research toward the more efficient utilization of natural and renewable resources. In an effort to tackle this issue, we developed an antibacterial textile nanocomposite material based on cotton and peat fibers with immobilized Cu-based nanostructures. In order to overcome poor wettability and affinity for Cu2+-ions, the substrate was activated by corona discharge and coated with the biopolymer chitosan before the in situ synthesis of nanostructures. Field emission scanning electron microscopy (FESEM) images show that the application of gallic or ascorbic acid as green reducing agents resulted in the formation of Cu-based nanosheets and mostly spherical nanoparticles, respectively. X-ray photoelectron spectroscopy (XPS) analysis revealed that the formed nanostructures consisted of Cu2O and CuO. A higher-concentration precursor solution led to higher copper content in the nanocomposites, independent of the reducing agent and chitosan deacetylation degree. Most of the synthesized nanocomposites provided maximum reduction of the bacteria Escherichia coli and Staphylococcus aureus. A combined modification using chitosan with a higher deacetylation degree, a 1 mM solution of CuSO4 solution, and gallic acid resulted in an optimal textile nanocomposite with strong antibacterial activity and moderate Cu2+-ion release in physiological solutions. Finally, the Cu-based nanostructures partially suppressed the biodegradation of the textile nanocomposite in soil.

Antibacterial activity of Cu-based nanoparticles synthesized on the cotton fabrics modified with polycarboxylic acids.

The fabrication of antimicrobial textile nanocomposite by in situ synthesis of Cu-based nanoparticles on cotton fabrics modified with different polycarboxylic acids was discussed in this study. In order to evaluate the influence of carboxyl group content on Cu2+-ions adsorption, their subsequent reduction with sodium borohydride and formation of Cu-based nanoparticles, cotton fabrics were modified with succinic, citric and 1,2,3,4-butanetetracarboxylic acids. It was shown that the larger the number of carboxyl groups in applied acid, the larger the content of free carboxyl groups on the fibers and consequently, the larger the Cu2+-ions uptake and total amounts of Cu-based nanoparticles. On the basis of the XPS and XRD measurements, it was suggested that synthesized nanoparticles were mixture of Cu2O and CuO. Fabricated nanocomposites provided maximum reduction of Gram-negative bacterium E. coli and Gram-positive bacterium S. aureus and controlled release of Cu2+-ions in physiological saline solution which are necessary prerequisites for infection prevention.

Biodegradation of cotton and cotton/polyester fabrics impregnated with Ag/TiO2 nanoparticles in soil.

This study discusses the biodegradation behavior of cotton and cotton/PET fabrics impregnated with Ag/TiO2 nanoparticles in soil. Biodegradation behavior was evaluated by standard test method ASTM 5988-03 based on determination of percentage conversions of carbon content to CO2 as well as by soil burial test and enzymatic hydrolysis with cellulase where the extent of biodegradation was estimated by the calculation of fabric weight loss. The morphological and chemical changes of fibers during biodegradation process were analyzed by SEM and FTIR spectroscopy, respectively. The results obtained by all applied methods suggested that Ag/TiO2 nanoparticles hindered the biodegradation of investigated cotton and cotton/PET fabrics. Soil burial test indicated faster biodegradation of the impregnated blend compared to impregnated cotton fabric which is attributed to smaller amount of fabricated Ag nanoparticles on the blend proved by AAS measurement. Similar trend was established by enzymatic hydrolysis of cotton fibers. Severe damage of cotton fibers in both fabrics due to biodegradation process was confirmed by SEM. However, the cotton fiber damage occurred to a lesser extent in the samples that were impregnated with Ag/TiO2 nanoparticles. PET fibers remained intact which was also indicated by FTIR analysis.

Impregnation of cotton fabric with silver nanoparticles synthesized by dextran isolated from bacterial species Leuconostoc mesenteroides T3.

This study was aimed to highlight the possibility of cotton fabric impregnation with silver nanoparticles synthesized by dextran isolated from Leuconostoc mesenteroides T3 in order to obtain antimicrobial properties. The fabrication of dextran was proved by FTIR spectroscopy. Particle sizes of synthesized dextran and silver nanoparticles were measured by dynamic light scattering method. The presence of silver nanoparticles on the surface of cotton fabric was confirmed by scanning electron microscopy, X-ray diffraction measurements and reflectance spectrophotometry. Antimicrobial activity of cotton fabric impregnated with silver nanoparticles was tested against bacteria Escherichia coli and Staphylococcus aureus, and fungus Candida albicans. The results indicated that synthesized silver nanoparticles can provide satisfactory antimicrobial activity. However, maximum reduction (99.9%) of all tested microorganisms can be obtained only when 1.0mmolL(-1) colloid consisting of silver nanoparticles is applied.

Sonophotocatalytic degradation of dye C.I. Acid Orange 7 by TiO2 and Ag nanoparticles immobilized on corona pretreated polypropylene non-woven fabric.

This study discusses the possibility of using corona pre-treated polypropylene (PP) non-woven fabric as a support for immobilization of colloidal TiO2 and Ag nanoparticles in order to remove dye C.I. Acid Orange 7 from aqueous solution. Dye removal efficiency by sonocatalysis, photocatalysis and sonophotocatalysis was evaluated on corona pre-treated fabric loaded with TiO2 nanoparticles, corona pre-treated fabric double loaded with TiO2 nanoparticles and corona pre-treated fabrics loaded with TiO2 nanoparticles before and after deposition of Ag nanoparticles. In addition, the stability of PP non-woven fabric during these processes was investigated. The substrates were characterized by SEM, EDX and AAS analyses. The change of the dye concentration was evaluated by UV-VIS spectrophotometry. Unlike sonocatalysis and photocatalysis, complete dye removal from both solution and non-woven fabric was obtained already after 240-270 min of sonophotocatalysis. Corona pre-treated PP non-woven fabric loaded with Ag nanoparticles prior to deposition of TiO2 nanoparticles provided excellent degradation efficiency and superior reusability. Sonophotocatalytic degradation of dye in the presence of all investigated samples was the most prominent in acidic conditions. Although this nanocomposite system ensured fast discoloration of dye solution, TOC values of water measured after sonophotocatalysis were not satisfactory because of PP degradation. Therefore, it is suggested to include TOC evaluation in each case study where different supports for TiO2 nanoparticles are used since these nanoparticles may guarantee the dye removal from solution but the stability of support could be problematic causing even more serious environmental impact.

Improved properties of oxygen and argon RF plasma-activated polyester fabrics loaded with TiO2 nanoparticles.

The potentials of low-pressure capacitively coupled RF oxygen and argon plasmas for the activation of polyester fibers surface that can enhance the deposition of colloidal TiO(2) nanoparticles were discussed. SEM and XPS analysis confirmed the plasma-induced morphological and chemical changes on the surface of polyester fibers. Oxygen and argon plasma pretreated polyester fabrics loaded with TiO(2) nanoparticles provided maximum reduction of Gram-negative bacteria E. coli and UV blocking. The self-cleaning effects tested on blueberry juice stains and photodegradation of methylene blue in aqueous solution proved excellent photocatalytic activity of TiO(2) nanoparticles deposited onto fiber surface. Although both plasmas significantly contributed to overall improvement of properties of such nanocomposite textile material, oxygen plasma treatment, in particular, enhanced the deposition of colloidal TiO(2) nanoparticles and thus ensured superior effects.

Characterization and quantitative analysis of surfactants in textile wastewater by liquid chromatography/quadrupole-time-of-flight mass spectrometry.

A method based on the application of ultra-performance liquid chromatography (UPLC) coupled to hybrid quadrupole-time-of-flight mass spectrometry (QqTOF-MS) with an electrospray (ESI) interface has been developed for the screening and confirmation of several anionic and non-ionic surfactants: linear alkylbenzenesulfonates (LAS), alkylsulfate (AS), alkylethersulfate (AES), dihexyl sulfosuccinate (DHSS), alcohol ethoxylates (AEOs), coconut diethanolamide (CDEA), nonylphenol ethoxylates (NPEOs), and their degradation products (nonylphenol carboxylate (NPEC), octylphenol carboxylate (OPEC), 4-nonylphenol (NP), 4-octylphenol (OP) and NPEO sulfate (NPEO-SO4). The developed methodology permits reliable quantification combined with a high accuracy confirmation based on the accurate mass of the (de)protonated molecules in the TOFMS mode. For further confirmation of the identity of the detected compounds the QqTOF mode was used. Accurate masses of product ions obtained by performing collision-induced dissociation (CID) of the (de)protonated molecules of parent compounds were matched with the ions obtained for a standard solution. The method was applied for the quantitative analysis and high accuracy confirmation of surfactants in complex mixtures in effluents from the textile industry. Positive identification of the target compounds was based on accurate mass measurement of the base peak, at least one product ion and the LC retention time of the analyte compared with that of a standard. The most frequently surfactants found in these textile effluents were NPEO and NPEO-SO4 in concentrations ranging from 0.93 to 5.68 mg/L for NPEO and 0.06 to 4.30 mg/L for NPEO-SO4. AEOs were also identified.

Efficiency of recycled wool-based nonwoven material for the removal of oils from water.

The aim of this study was to highlight the potential use of recycled wool-based nonwoven material for the removal of diesel fuel, crude, base, vegetable and motor oil from water. Sorption capacity of the material in water and in oil without water, oil retention, sorbent reusability and buoyancy in static and dynamic conditions were investigated. The results show high sorption capacity of recycled wool for different kinds of oil. This sorbent also exhibited excellent buoyancy after 24h of sorption as well as a good reusability since the decrease in sorption capacity did not exceed 50% of the initial value after five sorption cycles in oil without water.

Recycled wool-based nonwoven material as an oil sorbent.

The aim of this study was to highlight the possibility of using recycled wool-based nonwoven material as a sorbent in an oil spill cleanup. This material sorbed higher amounts of base oil SN 150 than diesel or crude oil from the surface of a demineralized or artificial seawater bath. Superficial modification of material with the biopolymer chitosan and low-temperature air plasma led to a slight decrease of sorption capacity. Loose fibers of the same origin as nonwoven material have significantly higher sorption capacities than investigated nonwoven material. White light scanning interferometry analysis of the fibers suggested that roughness of the wool fiber surface has an important role in oil sorption. The laboratory experiments demonstrated that this material is reusable. Recycled wool-based nonwoven material showed good sorption properties and adequate reusability, indicating that a material based on natural fibers could be a viable alternative to commercially available synthetic materials that have poor biodegradability.