Optimization of green biosynthesized visible light active CuO/ZnO nano-photocatalysts for the degradation of organic methylene blue dye.

Herein, CuO/ZnO nanocomposites at different ratios were successfully synthesized through a green biosynthesis approach. This was performed by harnessing the fungal-secreted enzymes and proteins during the sol-gel process for nanocomposites seed growth. All fabricated nanoparticles/nanocomposites were characterized using Fourier Transform Infra-Red (FT-IR) Spectroscopy, X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM-EDX) and X-ray Photoelectron Spectroscopy (XPS) analyses. The photocatalytic degradation efficacy of the synthesized nanocomposites was evaluated using a cationic methylene blue (MB) dye as a model of reaction. Results obtained from the FT-IR and EDX analyses revealed that CuO-NPs, ZnO-NPs, CuO/ZnO50/50, CuO/ZnO80/20, and CuO/ZnO20/80 were successfully prepared by harnessing the biomass filtrate of Penicillium corylophilum As-1. Furthermore, XRD and TEM revealed the variation in the particle size of the nanocomposites (10-55 nm) with the ratio of the nanoparticles. Notably, the size of the nanocomposites was proportionally increased with an increasing ratio of ZnO-NPs. XPS analysis affirmed the presence of both Cu and Zn in the nanocomposites with varying binding energies compared with individual nanoparticles. Furthermore, a high photo-degradation efficacy was achieved by increasing the ratio of ZnO-NPs in the nanocomposite formulation, and 97% of organic MB dye was removed after 85 min of irradiation using the CuO/ZnO20/80 nanocomposite.

Effect of cellulose nanocrystals on scaffolds comprising chitosan, alginate and hydroxyapatite for bone tissue engineering.

In this study, chitosan/alginate/hydroxyapatite/nanocrystalline cellulose scaffolds were successfully fabricated by the using of freeze-drying method, followed by dicationic crosslinking using CaCl2. The chemical structure and morphology along with mechanical properties of the formed scaffolds respecting to various CNC contents were studied by Fourier-transform infrared spectroscopy (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and mechanical compression test. Chemical interaction and electrostatic attraction between chitosan (CS) and alginate with various CNC ratios were affirmed by FTIR spectroscopy. Results depicted that, scaffolds containing CNC exhibited remarkable improvement in both swelling ratio up to 110% compared without CNC (63%) and compressive strength when compared with other scaffolds. In addition, the average pore size increased, dramatically, with increasing of CNC up to 230 µm. Porosity was also obeyed the sequence and attainted a maximum value at 93.6%. The growth and cell attachment of fibroblast cells of the selected scaffold were examined prolonging to the cell viability by using Alamar Blue (AB) and then confirmed using SEM. The results indicated that the scaffold comprising CNC has a promising cell growth and cell adherence, and thus expected to have a potent possibility for applications in bone tissue culture.

In-situ green myco-synthesis of silver nanoparticles onto cotton fabrics for broad spectrum antimicrobial activity.

In the realm of green synthesis of metals nanoparticles for medical textile application, silver nanoparticles (AgNPs) were biosynthesized in situ cotton fabrics for the first time by using fungi for rendering cotton fabrics antimicrobial activity with abroad range towards different pathogenic organisms. Herein, five different isolated fungi from medicinal plants were identified and optimized their growth media prior examined their ability to reduce Ag+ ions to AgNPs in-situ cotton fabrics along with ex-situ method. Synthesis of AgNPs were characterized by making use of instruments e.g. UV-vis spectroscopy, Transmission Electron Microscopy (TEM), Selected Area Electron Diffraction (SAED), Scanning Electron Microscopy (SEM), and Fourier Transform Infrared (FTIR). Whereas antimicrobial activities of the resultant cotton fabrics were investigated against Gram positive (S. aureus ATCC29213), Gram negative (E. coli ATCC 25922), Yeast (C. albicans ATCC10321) and, fungi (A. niger NRC 53). Results revealed the successful biosynthesis of AgNPs using different fungus strains whether in-situ cotton fabrics or ex-situ manner. The size of the resultant AgNPs by ex-situ method were varied (5-20 nm). The antimicrobial activity of the in-situ treated cotton samples exhibited different behaviors towards both pathogenic bacteria and fungi. This manner opens up a new way to discover the ability of nanobiotechnology to provide world with substitutional aids mimic to synthetic materials.

Green approach for one-pot synthesis of silver nanorod using cellulose nanocrystal and their cytotoxicity and antibacterial assessment.

Herein, this research addresses an innovative approach for one-pot synthesis of highly stabilized silver nanorods in powder form at concentration as high as feasible to be proposed in large-scale production via cellulose nanocrystals (CNC). For the first time, CNC without any surface modification in the presence of alkali is acting as both reducing and stabilizing agent for assembling of Ag nanorods. Extraction of CNC from cotton is carried out as per to acid hydrolysis technique. Thorough assessments of Ag nanorods formation, structural and morphological characteristics of Ag nanorods were investigated by making use of UV-vis spectroscopy, TEM, DLS, AFM and X-ray diffraction (XRD) analysis. Also, the antibacterial activity and cytotoxicity of Ag nanorod were investigated. Research outputs signify that, Ag nanorods has been successfully prepared through an effectively approach by virtue of the textural feature of CNC as a mediator. Results revealed the great tendency of CNC toward reducing and stabilizing the as formed Ag nanorods even at high concentration. Results also demonstrated that Ag nanorods have not merely remarkably antibacterial activity towards Gram-positive and Gram-negative bacteria, but safe for using in human life, which exhibited no effect on eukaryotic cells.

Sono-chemical synthesis of cellulose nanocrystals from wood sawdust using Acid hydrolysis.

Cellulose nanocrystal (CNC) is a unique material obtained from naturally occurring cellulose fibers. Owing to their mechanical, optical, chemical, and rheological properties, CNC gained significant interest. Herein, we investigate the potential of commercially non-recyclable wood waste, in particular, sawdust as a new resource for CNC. Isolation of CNC from sawdust was conducted as per acid hydrolysis which induced by ultrasonication technique. Thus, sawdust after being alkali delignified prior sodium chlorite bleaching, was subjected to sulfuric acid with concentration of 65% (w/w) at 60°C for 60min. After complete reaction, CNC were collected by centrifugation followed by dialyzing against water and finally dried via using lyophilization technique. The CNC yield attained values of 15% from purified sawdust. Acid hydrolysis mechanism exactly referred that, the amorphous regions along with thinner as well as shorter crystallites spreaded throughout the cellulose structure are digested by the acid leaving CNC suspension. The latter was freeze-dried to produce CNC powder. A thorough investigation pertaining to nanostructural characteristics of CNC was performed. These characteristics were monitored using TEM, SEM, AFM, XRD and FTIR spectra for following the changes in functionality. Based on the results obtained, the combination of sonication and chemical treatment was great effective in extraction of CNC with the average dimensions (diameter×length) of 35.2±7.4nm×238.7±81.2nm as confirmed from TEM. Whilst, the XRD study confirmed the crystal structure of CNC is obeyed cellulose type I with crystallinity index ∼90%. Cellulose nanocrystals are nominated as the best candidate within the range studied in the area of reinforcement by virtue of their salient textural features.

Laminating of chemically modified silan based nanosols for advanced functionalization of cotton textiles.

As per to silver nanoparticles/silicon dioxide nanoparticles (SiO2@AgNPs) properties (e.g., conductivity, reactant, adsorption, detachment and antimicrobial), many researchers were focused on its preparation technique. A core/shell of silicon dioxide and silver nanoparticles (SiO2@AgNPs) has been prepared by facile route. The as synthesized core/shell nanoparticles were chemically modified with two different silan compounds, nominated, vinyltriethoxysilan (VTEOS) and (3-aminopropyl)trimethoxysilan (APTEOS). World class facilities such as XRD, FT-IR, TEM, Particle size, DLS, SEM techniques were utilized for the nanoparticles characterization. The nanoparticulate system comprises SiO2@AgNPs, SiO2@AgNPs/APTEOS were applied to cotton fabric using butantetracarboxylic acid (BTCA) as across-linking agent. While UV irradiation by photo initiator was used as crosslinking agent for SiO2@AgNPs/VTEOS on cotton fabrics. The Treated cotton fabrics were evaluated for their surface morphology and heat transfer ability as well as antibacterial activity. The obtained data prove that the core/shell was successfully prepared, with AgNPs in core. In addition, both silan compounds (APTEOS, VTEOS) were successfully reacted with the outer shell SiO2. The results declared also that the treated fabrics exhibit a good antibacterial activity as well as good thermal properties.

Antidiabetic assessment; in vivo study of gold and core-shell silver-gold nanoparticles on streptozotocin-induced diabetic rats.

Recently, we have published a pioneering work on green biosynthesis and complete characterization of gold and core shell silver-gold nanoparticles (AuNPs and Ag@AuNPs). Herein, the so obtained nanoparticles are assessed for their antidiabetic activity in streptozotocin-induced diabetic rats. Thus, sixty-four male albino rats were divided into eight groups: control untreated; diabetic rats; diabetic rats received standard drug; diabetic rats received carrier only; diabetic rats received 0.5ml AuNPs; diabetic rats received 1ml AuNPs; diabetic rats received 0.5ml Ag@AuNPs and diabetic rats received 1ml Ag@AuNPs for twenty-one days. Results revealed that diabetic rats treated with AuNPs or Ag@AuNPs restored normal glucose level. In particular, Ag@AuNPs was found to significantly induce a reduction in blood glucose and restore both the high serum insulin level and glucokinase activity compared to the control normal rats. The results obtained disclose the effectual role of Ag@AuNPs in reducing the lipid profile, an anti-inflammatory effect in diabetic rats assessed using inflammatory markers IL-α and C-reactive protein (CRP). Histopathological examination of diabetic rats signifies distortion in the arrangement of cells around the central vein, inflammatory cells, pyknotic and apoptotic nuclei. Kidney of diabetic rat appears with vacuolation and pyknotic nuclei of some tubules. On the other hand, the liver of diabetic rat treated with Ag@AuNPs displayed normal hepatic cells with only few necrosis of hepatocytes. Ag@AuNPs restored the increased number of caspase-3 stained cells in the liver and kidney tissue in diabetic rats. In conclusion, Ag@AuNPs was observed to improve diabetic condition by limiting prolonged inflammation, suppressing oxidative stress and elevating the antioxidant defense system in diabetic rats which subsequently evoke the potential impact of AuNPs as a cost effective therapeutic cure in diabetic treatments and its complications.

Advancement in conductive cotton fabrics through in situ polymerization of polypyrrole-nanocellulose composites.

Current research was undertaking with a view to innovate a new approach for development of conductive - coated textile materials through coating cotton fabrics with nanocellulose/polypyrrole composites. The study was designed in order to have a clear understanding of the role of nanocellulose as well as modified composite thereof under investigation. It is anticipated that incorporation of nanocellulose in the pyrrole/cotton fabrics/FeCl3/H2O system would form an integral part of the composites with mechanical, electrical or both properties. Three different nanocellulosic substrates are involved in the oxidation polymerization reaction of polypyrrole (Ppy) in presence of cotton fabrics. Polymerization was subsequently carried out by admixing at various ratios of FeCl3 and pyrrole viz. Ppy1, Ppy2 and pp3. The conductive, mechanical and thermal properties of cotton fabrics coated independently with different nanocellulose/polypyrrole were investigated. FTIR, TGA, XRD, SEM and EDX were also used for further characterization. Results signify that, the conductivity of cotton fabrics increases exponentially with increasing the dose of pyrrole and oxidant irrespective of nanocellulose substrate used. While, the mechanical properties of cotton fabrics are not significantly affected by the oxidant treatment.

Solid state synthesis of starch-capped silver nanoparticles.

The present research addresses the establishment of a technique which is solely devoted to environmentally friendly one-pot green synthesis of dry highly stable powdered silver nanoparticles (AgNPs) using starch as both reductant and stabilizing agent in the presence of sodium hydroxide. It is believed that the sodium hydroxide can improve the reduction potential of starch. Thus when the alkali treated starch is submitted to addition of silver nitrate (AgNO3), the alkali treated starch induces the well-established dual role of starch; reduction of silver ions (Ag(+)) to AgNPs and capping the as-formed AgNPs to prevent them from further growth and agglomeration. Beside assessment of AgNPs formation, structural and morphological characteristics of AgNPs are investigated by making use of UV-vis spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential, FT-IR and X-ray diffraction (XRD) analysis. Research outputs signify (a) the absorbance around 410-420nm in the UV-vis spectra of AgNPs appears most, probably owing to the presence of nanosized silver particles and the intensity of this peak increases by increasing AgNO3 concentration; (b) that highly stable AgNPs with well-dispersed particle are successfully prepared using the present research-based innovation; (c) that the size of AgNPs does not exceed 30nm with sphere-like morphology even at the highest Ag(+) concentration employed during synthesis operation; (d) that the XRD and FT-IR confirm the successful preparation of pure AgNPs without noticeable impurities; (d) and that the one-pot synthesis of powdered AgNPs in large scale is clean and easily operated and easily transportation which may be applied as per demands of industries such as textile and painting industry.

Durable antibacterial and UV protections of in situ synthesized zinc oxide nanoparticles onto cotton fabrics.

Herein we represent a new discovery based on amine material called hexamethyltriethylene tetramine (HMTETA). We have observed that when an aqueous solution of Zn(NO3)·6H2O was added to aqueous solution of HMTETA followed by shaking for a time, the colorless solution was converted to milky color under the alkaline medium provided by HMTETA prior to formation of uniform zinc oxide nanoparticles (ZnO NPs). The latter are in situ formed within the cotton fabrics without the support of capping or other stabilizing agents. Obviously, then, the new made of formation of ZnO NPs speaks of a single-stage process where cotton fabric is immersed in a prepared solution of the new precursors through which binding of ZnO NPs into the textile fabrics takes place. Textile fabrics are, indeed, used as a template, which is capable of maintaining the size and surface distribution of the as-synthesized nanoparticles in a uniform domain. It is also likely that nanoparticles is confined inside the fibril and microfibrils of the cotton fibers. World-class facilities have been employed to follow up the synthesis of ZnO NPs, their characterization and their application to confer, in particular, high durable antibacterial and UV protective function on cotton fabrics.

Radically new cellulose nanocomposite hydrogels: Temperature and pH responsive characters.

Innovation produced for synthesis of radically new stimuli-responsive hydrogels were described. The innovation is based on inclusion of cellulose nanowhiskers (CNW)-polyacrylamide (PAAm) copolymer in poly N-isopropyl acrylamide (PNIPAm) semi interpenetrating network (IPN) hydrogel. After being prepared as per free radical polymerization of AAm onto CNW, the as prepared copolymer was incorporated in a polymerization system, which comprises NIPAm monomer, bismethylene acrylamide (BMA) crosslinker, K2S2O8 initiator and TEMED accelerator, to yield CNW-PAAm-PNIPAm nanocomposite hydrogels. The latter address pH-responsive hydrogel as well as temperature-responsive. Hydrogels exhibit the highest equilibrium swelling ratio (ESR) in acidic medium (pH 4). Meanwhile they perform good swelling behavior and hydrophilicity at a temperature of 32°C. These hydrogels carry the characteristic features of CNW-PAAm copolymer as conducted from FTIR and TGA. The hydrogels are homogenous and well-proportioned network structure with highly connected irregular pores with a large size ranging from 30 to 100nm as concluded from SEM.

Thermal responsive hydrogels based on semi interpenetrating network of poly(NIPAm) and cellulose nanowhiskers.

A hybrid hydrogel nanocomposite was developed based on semi interpenetrating network that was formed as a result of concurrent free radical polymerization of N-isopropylacrylamide (NIPAm) and methylenebis acrylamide (MBA) crosslinker along with cellulose nanowhiskers (CNWs). CNWs were synthesized through sulfuric acid hydrolysis and used in preparation of semi interpenetrating network (IPN). CNWs have considered as reinforcement materials for poly(NIPAm) because CNWs were distributed as strengthening entities in Poly(NIPAm). N-isopropylacrylamide was polymerized in presence of methylenebis acrylamide crosslinking agent using K2S2O8 as initiator at 700 C for 1h. The resulting hydrogel's structure, morphology, thermal sensitive property and swelling behavior were investigated. It was found that introducing CNWs into Poly(NIPAm) causes a huge increase in the value of equilibrium swelling ratio (ESR) as compared with the pure PNIPAm. The ESR ranges from 21.6g/g to 5 g/g as the swelling temperature changes from 310 °C to 340 °C; hence, the hydrogel exhibits a good responsive temperature at about 320 °C.

Bio-synthesis and applications of silver nanoparticles onto cotton fabrics.

Recently, biosynthesis of metal nanoparticles has drawn considerable attention due to environment-ecofriendly and sustainable methods. Herein, fungus Fusarium solani was selected as candidate for biosynthesis of silver nanoparticles (AgNPs). Factors affecting the biomass concentration, pH of the reaction medium, AgNO(3) concentration and the ratio of AgNO(3) to biomass concentration on the production of AgNPs were extensively studied. Optimum conditions for biosynthesis of AgNPs could be attained using biomass of F. solani (10 g/100ml); AgNO(3) (0.078 g/100 ml); pH, 12; temperature, 25 °C and duration, 24h. Under these conditions, the maximum concentration of well stabilized AgNPs obtained was 2000 ppm with a mean diameter range of 8-15 nm. Such solution is unequivocally feasible for industrial applications. A diluted solution containing 50 ppm AgNPs was applied to cotton fabrics which imparts antibacterial activity to the fabric with 97% and 91% reduction of Staphylococcus aureus and Escherichia coli, respectively.