Simultaneous in situ synthesis of nano silver and wool fiber fineness enhancement using sulphur based reducing agents

Fine and high-performance protein fibers from meat goat hairs via manipulation of keratin alignment and crosslinkages

We have converted waste coarse and short hairs of meat goats to high-value, fine, long, and elastic protein fibers via manipulation of keratin alignment and crosslinkages. The shortage of non-petroleum-based fibers has become one of the most prominent concerns. However, few technologies could convert such coarse hairs to fine and flexible fibers for textile uses due to limitations in extensions of fibers, less than 100% of their initial length, and poor flexibility retention of extended fibers, less than 20% of breaking elongation. Limited stretchability and flexibility retention of hair fibers mainly resulted from the difficulty in recovery of crosslinkages in stretched fibers. Here, we used a series of dithiols via multiple cycles of reduction, drawing, and oxidation to produce fine and flexible fibers from coarse and short wool for the first time. Dithiols with long backbones ensured sufficient crosslinkages in proteins after high ratios of drawings. Besides, long crosslinkages brought by dithiols secured sufficient movement between protein molecules and prevented of rupturing chains of protein molecules. As a result, short and coarse hairs of meat goats were turned into long and fine fibers, 350% of their original lengths and 54% of their original diameters, with excellent performance properties, with retentions of 170% of tenacity, and 50% of breaking elongation compared to original hairs. Also, a set of models developed to quantify the effects of extensions of fibers and structures of crosslinkers on the mechanical properties of fibers guides scientists and engineers on property improvement of materials via controlled crosslinkings.

Sustainability insights into the synthesis of engineered nanomaterials - Problem formulation and considerations

Engineered nanomaterials (ENMs) have been introduced into the market for a wide range of applications. As per the literature review, the fabrication of new generations of ENMs is starting to comply with environmental, economic, and social criteria in addition to technical aspects to meet sustainability criteria. At this stage, identification of the appropriate criteria for the synthesis of ENMs is critical because the technologies already developed at the lab scales are being currently transferred to pilot and full scales. Hence, the development of scientific-based methodologies to identify, screen, and prioritize the involved criteria is highly necessary. In the present manuscript, a fuzzy-Delphi methodology is adopted to identify the main criteria and sub-criteria encompassing the sustainable fabrication of ENMs, and to explore the "degree of consensus" among the experts on the relative importance of the mentioned criteria. The "health and safety risks" respecting the equipment and the materials, solvent used, and availability of "green experts" were identified as the most critical criteria. Furthermore, although all the criteria were identified as being important, some criteria, such as "solvent" and "raw materials cost", raised a lower degree of consensus, indicating that various "degrees of uncertainties" still exist regarding the level of importance of the studied criteria.

Biosynthesis of reusable and recyclable CuO@Magnetite@Hen Bone NCs and its antioxidant and antibacterial activities: a highly stable magnetically nanocatalyst for excellent reduction of organic dyes and adsorption of polycyclic aromatic hydrocarbons

For the first time, through a fast, eco-friendly and economic method, the aqueous extract of the leaf of Euphorbia corollate was used to the green synthesis of the highly stable CuO@Magnetite@Hen Bone nanocomposites (NCs) as a potent antioxidant and antibacterial agent against Pseudomonas aureus, Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae pathogenic bacteria. The biosynthesised NCs were identified using the scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy, elemental mapping, X-ray diffraction (XRD), Fourier transforms infrared spectroscopy and UV-vis analytical techniques. Also, the radical scavenging activity using (2,2-diphenyl-1-picrylhydrazyl) method was used to evaluate the antioxidant activity of the NCs. The stability of nanocatalyst was monitored using the XRD and SEM analyses after 30 days from its synthesis. Furthermore, its excellent catalytic activity, recycling stability, and high substrate applicability were demonstrated to the adsorption of the polycyclic aromatic hydrocarbons of the light crude oil from Shiwashok oil fields and destruction of methylene blue and methyl orange as harmful organic dyes at ambient temperature using UV-vis spectroscopy. Moreover, the green CuO@Magnetite@Hen Bone NCs were recovered and reused several times without considerable loss of its catalytic activity.

Facile and environmental benign in situ synthesis of silver nanoparticles for multifunctionalization of wool fibers

In this manuscript, we report the simple method to multifunctional wool fiber surfaces. The multifunctional wool fibers were devised with brilliant coloration, antimicrobial activity, and UV-protection property. These multifunctional properties were progressed by in situ assemble of silver nanoparticles (Ag NPs) into the wool fiber surface using green cleaner one-pot route. The proteins existing in the wool fibers acted being a redox active bio-template, facilitating the reduction of Ag⁺ to Ag⁰, with simultaneous binding of the produced Ag NPs both on the surface and within the center of the wool fibers. The entire results showed that the Ag NP in situ-incorporated wool fibers can be used as colorant wool fibers effectively, and these colored fibers also exhibit an improvement for multi-functionality properties.

Natural iron ore as a novel substrate for the biosynthesis of bioactive-stable ZnO@CuO@iron ore NCs: a magnetically recyclable and reusable superior nanocatalyst for the degradation of organic dyes, reduction of Cr(vi) and adsorption of crude oil aromatic compounds, including PAHs

For the first time, stable ZnO@CuO@iron ore nanocomposites (NCs) were green synthesized using magnetic iron ore as a natural substrate through an eco-friendly, simple and cost-effective method.

Silver nanomaterials as future colorants and potential antimicrobial agents for natural and synthetic textile materials

Over the past few years, antimicrobial textiles have gained considerable interest for use in different application fields.

A robust super-paramagnetic TiO2:Fe3O4:Ag nanocomposite with enhanced photo and bio activities on polyester fabric via one step sonosynthesis

High intensity ultrasound was used for the synthesis and simultaneous deposition of TiO2:Fe3O4:Ag nanocomposites on polyester surface providing a feasible route for imparting magnetic and enhanced antibacterial and self-cleaning activities with controllable hydrophilicity/hydrophobicity at low temperature. Synergistic impact of sonochemistry and physical effects of ultrasound originating from implosive collapse of bubbles were responsible for the formation and adsorption of nanomaterials on the fabric surface during ultrasound irradiation. The increase in photocatalytic activity of TiO2 was obtained attributing to the co-operation of iron oxide and silver nanoparticles nucleated on TiO2 surface boosting the electron-hole pair separation and prolonging their recombination rate. The process was further optimized in terms of reagents concentrations including Fe(2+)/TiO2 and Ag/TiO2 molar ratios using central composite design in order to achieve the best self-cleaning property of the treated fabric. The magnetic measurements indicated the super-paramagnetic behavior of the treated fabric with saturation magnetization of 4.5 (emu/g). Findings suggest the potential of the proposed facial method in producing an intelligent fabric with durable multi-functional activities that can be suitable for various applications including medical, military, bio-separation, bio-sensors, magneto graphic printing, magnetic screens and magnetic filters.

In Situ Photo Sonosynthesis of Organic/Inorganic Nanocomposites on Wool Fabric Introducing Multifunctional Properties

Here, a novel and efficient process is introduced for producing wool fabric with multifunctional features through facile in situ photosonochemical synthesis of organic/inorganic nanocomposites. The fabric was treated with titanium isopropoxide, silver nitrate and ammonia in a sonobath for 1 h at 75-80°C. The crystal phase of the sono-treated samples was characterized by X-ray diffraction. The uniform distribution of the nanocomposite on the fiber surface was proved by field emission scanning electron microscope, energy dispersive X-ray and mapping patterns. Further, the composition of the nanocomposites was investigated by X-ray photoelectron spectroscopy. The sono-treated wool fabrics illustrated excellent photocatalytic activities toward discoloration of Methylene Blue under sunlight and UV-A irradiation. Also the fabrics indicated reasonable antibacterial/antifungal activities against Staphylococcus aureus, Escherichia coli and Candida albicans. The tensile properties of the sono-treated fabrics enhanced comparing to the untreated and even conventional stirrer-treated fabrics. Moreover, a central composite design based on response surface methodology was used to study the influence of titanium isopropoxide and silver molar ratio on the prepared nanocomposites sonobath. Finally, the optimum molar ratio was reported for the best responses.

Biogenic Strain of Silver and Selenium Nanoparticles by Pseudomonas fluorescens and Cladosporium sp. JAPSK3 Isolated from Coal Mine Samples and Their Antimicrobial Activity

Selenium and silver have unique properties and great potential in the field of physics, chemistry and biology. The bacterial strain Pseudomonas fluorescens was isolated by using Kings'B media and Cladosporium sp. was isolated by using potato dextrose agar for soil sample collected from Andhra Pradesh coal field of Singareni. Rapid formation of stable silver and selenium nanoparticles ( AgNPs ; SeNPs ) were observed on exposure of the microbial culture with solution of silver nitrate and sodium selenite. The nanoparticles were characterized by UV-visible spectroscopy, X-ray diffraction (XRD) and atomic force microscopy (AFM). Further, the biologically synthesized nanoparticles were found to have efficient antimicrobial activity against pathogenic bacteria, thus implying significance of the present study in production of biomedical products. AgNPs synthesized by P. fluorescens showed more antimicrobial activity than Cladosporium sp. As the AgNPs are much smaller in size, they showed effective antimicrobial activity when compared to that of SeNPs which showed less effective antimicrobial activity in both P. fluorescens and Cladosporium sp. The microbes are capable of reducing both AgNPs and SeNPs . The biological synthesis of nanoparticles is useful when compared with other physical and chemical methods as they are eco-friendly.

Sonosynthesis of nano TiO2 on wool using titanium isopropoxide or butoxide in acidic media producing multifunctional fabric

This study presents a novel idea to prepare nanocrystalline structure of TiO2 under ambient pressure at 60-65 °C using in situ sonochemical synthesis by hydrolysis of either titanium isopropoxide or titanium butoxide in an acidic aqueous solution. The nano titanium dioxide coated wool fabrics possess significant antibacterial/antifungal activity and self-cleaning property by discoloring Methylene blue stain under sunlight irradiation. This process has no negative effect on cytotoxicity and tensile strength of the sonotreated fabric even reduces alkaline solubility and photoyellowing and improves hydrophilicity. More titanium isopropoxide or titanium butoxide as a precursor led to higher photocatalytic activities of the treated fabrics. Also introducing more ethanol improved the adsorption of TiO2 on the wool fabric surface leading to enhanced photocatalytic activity. EDS and XRD patterns, SEM images, X-ray mapping confirmed the presence of nano TiO2 particles on the fabric surface. The role of both solvent and precursor concentrations on the various properties of the fabric was investigated and the optimized conditions were obtained using response surface methodology.