Clean synthesis of silver nanoparticles (AgNPs) on polyamide fabrics by Verbascum thapsus L. (mullein) extract: characterization, colorimetric, antibacterial, and colorfastness studies.

The production of antibacterial colored textiles using nanomaterials (NMs) has become an ideal goal from both a research and industrial perspective. In this study, the clean synthesis and characterization of silver nanoparticles (AgNPs) on polyamide fabrics were performed using mullein extract for the first time. Natural dyes were extracted from mullein leaves using an ultrasonic method, with an optimal amount of 15 g/L. The synthesized AgNPs in different ratios of mullein extract and Ag ions were analyzed (using UV-visible spectroscopy) and dynamic light scattering (DLS). It was found that AgNPs synthesized with a ratio of 1:4 of mullein extract: to Ag ions had a diameter of 85 nm. The active site groups of the synthesized AgNPs were characterized using Fourier transform infrared spectroscopy (FT-IR). Nylon fabrics dyed with different ratios of mullein extract and Ag ions exhibited acceptable color strength values (K/S) of 3.36. Furthermore, the reduction in bacterial growth for dyed fabrics improved with an increase in the ratio of Ag ions, with a 100% reduction observed for a sample dyed with mullein extract: Ag ions at a ratio of 1:4. Overall, this method offers a simple, low-cost, and compatible process with environment without the consumption of any chemicals to producing nylon with acceptable antibacterial and dyeing properties.

Wool dyeing using Ziziphus bark extract as a natural dye: studies on the dyeing, antibacterial, and antioxidant characteristics.

Considering the growing importance of natural colorants and sustainable products, the research on application of natural dyes has been focused on new color resources, identification, and standardization of natural dyes. Hence, the extraction of natural colorants available in Ziziphus bark was performed by ultrasound technique and its application on the wool yarn to produce the antioxidant and antibacterial fibers. The optimal conditions for the extraction process were as follows: ethanol/water (1/2 v/v) as solvent, concentration of Ziziphus dye 14 g/L, pH 9, temperature 50 °C, time 30 min, and L.R ratio 50:1. Moreover, the effect of important variables for application of Ziziphus dye on the wool yarn was investigated and optimized temperature 100 °C, concentration of Ziziphus dye 50% o.w.f., time for dyeing 60 min and pH 8, and L.R 30:1. The reduction values of Gram-negative and Gram-positive bacteria on dyed samples at optimized condition were 85% and 76%, respectively. Moreover, the antioxidant property of dyed sample was 78%. The color variations on the wool yarn were produced with diverse metal mordants, and color fastness properties were measured. Ziziphus dye not only can be used as an origin for a natural dye, but also provided the antibacterial and antioxidant agent on the wool yarn, which can be a step towards the fabrication of green products.

Using a Dendritic Sensor as a Feasible Method for Detection of Copper in Water Samples.

Due to the severe dangers of copper on human health, development of identification and measurement copper methods in aquatic environments as well as prevention transfer methods of these substances to water resources have received much attention. Among of this expansion, rapid, simple, safe, sensitive and economically viable detection methods are more considerable. In this paper, the sensor activity of the poly(amidoamine) dendrimer containing eight methoxy groups modified with naphthalimide fluorescent derivative is studied. The sensor potential of dendrimer-naphthalimide fluorescence was evaluated in various solvents with different polarities, and results indicated that the detection of cuprum cations (Cu2+) is possible at low concentration. Also, the fluorescence properties of dendrimer-naphthalimide system are measured in the presence of diverse metal cations. In light of above, from the obtaining results, it can be concluded that dendritic sensor can be used as a feasible method to detect of copper in water samples in low concentrations.

Application of Achillea millefolium extract as a reducing agent for synthesis of silver nanoparticles (AgNPs) on the cotton: antibacterial, antioxidant and dyeing studies.

The phyto-synthesis of silver nanoparticles and cotton dyeing with natural colorants can reduce the environmental impact of the process considerably. In this study, the extraction of natural colorants from Achillea millefolium petals was optimized by ultrasound technique. The AMP extract was applied for synthesis of silver nanoparticles (Ag NPs) on the cotton fabrics. The dyeing, antibacterial and antioxidant characteristics of cotton samples were investigated to optimize the process and evaluate its efficiency. The AMP extract had good substantivity towards cotton fabrics and the presence of tannic acid, as an environmentally-friendly mordant, further improved the absorption of AMP dye. The antibacterial and antioxidant activities of the dyed samples with AMP extract of were 50%and 60%, respectively. The addition of TA and Ag enhanced the antibacterial and antioxidant activities on the cotton samples to over 99%.

Eco-Friendly Procedure for Rendering the Antibacterial and Antioxidant of Cotton Fabrics via Phyto-Synthesized AgNPs With Malva sylvestris (MS) Natural Colorant.

There is a growing interest for producing multifunctional cellulose fabrics using green and sustainable technology. In this study, we explored an eco-friendly procedure for dyeing cotton fabrics with Malva sylvestris (MS) as a natural colorant and rendering antibacterial cotton fabric by the silver nanoparticles. MS colorants were extracted from dried petals in water using the ultrasound technique, cotton fabrics were dyed with the extracted MS colorant at 100°C for 90 min. The colorimetric data and colorfastness properties were investigated in the absence and presence of tannic acid (TA) as a bio-mordant. Results indicated that MS dye had a high potential for reducing the silver nitrate, so that the silver particle size distribution on cotton fabric was obtained 50-80 nm, and TA had a positive effect on the MS extract and reduced Ag on the cotton. Furthermore, the reduction of bacterial growth of the dyed cotton considerably (up to 99%) improved by AgNPs. The wash-, and light-fastness properties of samples dyed with MS were enhanced from moderate to good-very good by mordanting.

Inorganic nanoparticles and natural dyes for production of antimicrobial and antioxidant wool fiber.

Ag/Cu2O/ZnO nanoparticles (NPs) were synthesized in situ on wool yarns. The wool yarns were subsequently dyed with the roots and stems of berberis vulgaris. The antibacterial, antioxidant, and dyeing properties of the treated wool yarns were studied. Scanning electron microscopy (SEM), differential scanning calorimeters (DSC), and weight gain (%) analyses were employed for the characterization of the treated samples. The results indicated that the highest color strength (K/S) was obtained at a dye concentration of 50% over the weight of fiber (o.w.f.), temperature 100 °C, time 60 min, and pH 5. Moreover, the antioxidant and antimicrobial activities of the treated samples with NPs, and dyed with roots and stems of berberis vulgaris were excellent (about 100%). The treated samples with Ag NPs and dyed with the natural dyes showed very high antimicrobial activity (> 84%) after 10 repeated washing cycles. Finally, the colorfastness properties of the dyed and treated wool samples against washing and light irradiation were studied. It was concluded that the roots and stems of berberis vulgaris could be considered as suitable natural colorants for dyeing of wool yarns with acceptable colorfastness properties, excellent antimicrobial and antioxidant activities.

Grafting of chitosan-acrylamide hybrid on the wool: Characterization, reactive dyeing, antioxidant and antibacterial studies.

This study presents a new approach to enhance reactive dye uptake and functional finishing of wool yarns via simple grafting with synthesized chitosan-acrylamide (Ch-Ac) hybrid. To this, Ch-Ac was synthesized and characterized with fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. Then, Ch-Ac was grafted on wool, characterized with FTIR, SEM, and weight gain analysis and dyeability with two commercial reactive dyes. Results showed that Ch-Ac treated wool could be dyed at lower temperatures (ca. 40 °C), times (ca. 30 min), and amount of reactive dye (2% owf) as compared to raw wool. Also, deeper shades not obtainable in conventional dyeing could be attained using Ch-Ac treated wool. In addition, Ch-Ac treatment imparted very good radical scavenging and excellent antibacterial activity against gram-negative (E. coli) and gram-positive (S. aureus) bacteria. Color fastness results confirmed that Ch-Ac treatment had no adverse effect on durability of dyes against washing, light, rubbing and perspiration. The results of this study clearly indicated that Ch-Ac can be used in eco-friendly functional finishing of wool with enhanced reactive dye uptake, minimized residual dye in wastewater, saving in consumption of chemicals, energy, and time of dyeing.

Functionalization of poly(amidoamine) dendrimer-based nano-architectures using a naphthalimide derivative and their fluorescent, dyeing and antimicrobial properties on wool fibers.

Novel naphthalimide-poly(amidoamine) dendrimer fluorescent dyes were synthesized, and their structures were identified and confirmed using different characterization methods such as Fourier transform infrared, (1) H NMR, (13) C NMR, differential scanning calorimetry, elemental analysis and UV-vis spectroscopy. The spectrophotometric studies demonstrated absorption maxima (λmax ) and extinction coefficient (εmax ) values in the ranges of 429-438 nm and 25,635-88,618 L/mol/cm, respectively. The dyeing, fastness and antimicrobial properties of dyed wool fibers were examined. Colorimetric measurements demonstrated a greenish-yellow hue with remarkable fluorescence intensity on dyed wool. Although the fastness properties of naphthalimide dye on wool fibers were poor/moderate, color fastness was appreciably improved through modification of the dye using dendrimers. The results revealed that the newly synthesized dyes are potent antimicrobial agents on wool fibers. Overall, it was deduced that poly(amidoamine) (PAMAM) dendrimers could be exploited as a promising tool in tailoring the different properties of naphthalimide dyes, being suitable for dyeing and antimicrobial finishing agents for wool fibers. Copyright © 2015 John Wiley & Sons, Ltd.