Showing papers in "journal of nanostructure in chemistry in 2018"
TL;DR: Graphene- and graphene oxide-based nanomaterials have gained broad interests in research because of their unique physiochemical properties and their substantial use in medicine and biology.
Abstract: Graphene- and graphene oxide-based nanomaterials have gained broad interests in research because of their unique physiochemical properties. The 2D allotropic structure allows it to be used in various biological fields. The biomedical applications of graphene and its composite include its use in gene and small molecular drug delivery. It is further used for biofunctionalization of protein, in anticancer therapy, as an antimicrobial agent for bone and teeth implantation. The biocompatibility of the newly synthesized nanomaterials allows its substantial use in medicine and biology. The current review summarizes the chemical structure and biological application of graphene in various fields.
326 citations
TL;DR: An overview of the plant-mediated synthesis of metal nanoparticles, possible compounds, and mechanisms that might be responsible for the reduction process as well as the potential pharmacological applications, currently available nanopharmaceutical products and their marketing status are discussed in this paper.
Abstract: Green chemistry approaches for the synthesis of metallic nanoparticles have become a new and promising field of research in recent years. Synthesis of metal nanoparticles [like gold (Au), silver (Ag), lead (Pb), platinum (Pt), copper (Cu), iron (Fe), cadmium (Cd), and other metal oxides such as titanium oxide (TiO), zinc oxide (ZnO), etc.] by various chemical and physical approaches as well as the biological approaches mediated by number of microorganisms have been actively found. Plant-mediated synthesis approaches are found to be more reliable and economic route to synthesize these metal nanoparticles. Owing to the biodiversity of plant biomasses, the actual mechanism by which the plant constituents have contributed to the synthetic process is yet to be fully known. Although the feasibility of controlling, the size and shape of nanoparticles by variation in reaction conditions have been demonstrated in many studies. Conventionally, nanoparticles are synthesized by chemicals and physicochemical methods using several chemicals which later on become accountable for various risk due to their general toxicity, so that solving the objective biological approaches is coming up to fill these gaps. The plant-mediated synthesis process undergoes highly controlled approaches for making them suitable for metal nanoparticle synthesis. In addition, biological synthesis of metallic nanoparticles is inexpensive, one-step, and eco-friendly method. In addition, the plant-mediated nanoparticles are used as potential pharmaceutical agents for various diseases such as malaria, HIV, cancer, hepatitis, and other diseases. Including this some other relevant information regarding nanopharmaceutical products, companies that are involve in the manufacturing and commercialization process and their clinical trial status are also discussed. This review article gives an overview of the plant-mediated synthesis of metal nanoparticles, possible compounds, and mechanisms that might be responsible for the reduction process as well as the potential pharmacological applications, currently available nanopharmaceutical products and their marketing status.
249 citations
TL;DR: A brief overview on the emerging role of fungi in the synthesis of metal nanoparticles, possible mechanisms and their potential bio-prospective applications is provided.
Abstract: Nanotechnology mainly involves the fabrication, manipulation, and utilization of materials in nano size (materials having size less than a micron to that of individual atoms). However, nanoparticles can be synthesized by several chemical and physical approaches; now, it is also possible to integrate the use of biological entities. In recent years, mycogenesis of nanoparticles is considered as a prominent way where fungi can be used for the production of nanostructures with desirable shape and size intracellularly or extracellularly. Several researchers have reported that NADH-dependent nitrate reductase enzyme plays an important role in transformation of metal ions into metal nanoparticles. The size and shape of the nanoparticles depend on the microorganism utilized and experimental condition employed during synthesis process. Nanoparticles synthesized from microbes are safe, environmental benign and have several applications in agriculture, textile, medicine, drug delivery, biochemical sensors and allied areas. Future challenges may include large-scale production, enhancement of stability, reduced time to obtain desirable shape and size and their possible applications in several fields. In this review paper, we provide a brief overview on the emerging role of fungi in the synthesis of metal nanoparticles, possible mechanisms and their potential bio-prospective applications.
156 citations
TL;DR: In this paper, an eco-friendly, biosynthesis of silver nanoparticles (AgNPs) using stem bark extract of Diospyros montana was reported, which was confirmed by visual observation as color change.
Abstract: The present study reports an eco-friendly, biosynthesis of silver nanoparticles (AgNPs) using stem bark extract of Diospyros montana. Initially, the synthesis of AgNPs was confirmed by visual observation as color change. Further, the morphology of the biosynthesized nanoparticles, average size and presence of elemental silver were characterized by UV–Visible spectroscopy, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray and dynamic light scattering spectrometer. Qualitative phytochemical screening and FTIR spectral peaks supported the role of phytochemicals in bark extract for the metal reduction, stabilization and capping of silver nanoparticles. XRD studies demonstrated that crystalline nature and their average size of nanoparticles was 28 nm as determined by Scherrer’s formula. The antioxidant ability of AgNPs and plant extract was analyzed using DPPH and Hydrogen peroxide assay. The percentage of DPPH and H2O2 activity was increased with increasing concentration of AgNPs. In vitro antibacterial effect of various concentration of AgNPs was investigated against both Gram positive (B.subtilis and S.aureus) and Gram negative (E.coli and K.aerogenes) bacterial strains. The result shows that biosynthesized AgNPs have significant antibacterial activity.
120 citations
TL;DR: A facile, eco-friendly synthesis of zinc oxide nanoparticles (ZnO NPs) employing Bauhinia tomentosa leaf extract as bioreducing agent was reported in this paper.
Abstract: A facile, eco-friendly synthesis of zinc oxide nanoparticles (ZnO NPs) employing Bauhinia tomentosa leaf extract as bioreducing agent was reported. The green-synthesized ZnO NPs were characterized by UV–Vis, TEM, EDX, XRD, and FTIR analyses. The formation of ZnO NPs was confirmed by the appearance of characteristic SPR peak at 370 nm due to the collective oscillation of electrons in the conduction band in UV–Vis spectra. The hexagonal morphology exhibiting nanosized ZnO was observed from the TEM and XRD analyses. The chemical bonds present in the as-synthesized ZnO NPs were identified by FTIR analysis. ZnO NPs showed a significant antibacterial activity against Gram-negative bacteria P. aeruginosa and E. coli than Gram-positive bacteria. Results of this study demonstrated that B. tomentosa leaf extract containing phytochemicals such as alkaloids, terpenoids, flavonoids, tannins, carbohydrates, and sterols possess bioreducing property for ZnO synthesis and the obtained ZnO NPs could be employed effectively as a better bactericidal agent for biological applications.
94 citations
TL;DR: A 360° view point on the nanomaterials which are used for solar energy harnessing with respect to environmental and energy application and the future scope of nanommaterials for real-world applications is provided.
Abstract: The nanostructured materials offer various advantages as they provide more flexible space for ease reconstruction, as their nanosize expands the limits and results in confinement effect, enhanced mechanical stability, and large surface area, and make them suitable for photocatalytic activities. The advancement in synthesis techniques provides the freedom to alter its physical properties as per the demand. This article provides a 360° view point on the nanomaterials which are used for solar energy harnessing with respect to environmental and energy application. The discussion emphasizes on various synthesis methods of nanostructured materials, their mechanistic features, usage in demanding applications such as photosplitting of water for hydrogen production, artificial photosynthesis, and water and wastewater treatment with an endnote highlighting the future scope of nanomaterials for real-world applications.
86 citations
TL;DR: In this article, the synthesis of zinc oxide nanoparticles using plant extracts has been investigated and shown to be a cost-effective and efficient method of biological synthesis of NPs and it could be an appropriate replacement to typical chemical methods for synthesizing NPs.
Abstract: Due to distinguishing characteristics of nanoparticles (NPs) in terms of size, shape, chemical composition, transmittal and different applications, nanotechnology is considered as an interesting domain of research. Application of metallic NPs is important because of the diminution of dimensions and thus the unique thermal, optical and electronic properties. This research attempts to explore the synthesis of zinc oxide NPs. Zinc oxide NPs have been synthesized using cherry extract under different pH, temperature and concentration and then optimum conditions for the synthesis of them were determined. For further investigations, UV–Vis spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier infrared transformation spectroscopy (FTIR) were used. The solution containing zinc oxide NPs showed a major absorbance of 378 nm which confirmed the synthesis of zinc oxide NPs, and spherical morphology of NPs was observed in SEM images. Zinc oxide NP sizes were 6.5 and 20.18 nm which are obtained by UV–Vis spectra and XRD spectrum, respectively. Also, based on the FTIR spectra of the extract obtained before and after the synthesis, the existence of the reducing agents in herbal extract was confirmed. According to this study, the biological synthesis of NPs using plant extracts can be considered as a cost-effective and efficient method of biological synthesis of NPs and it could be an appropriate replacement to typical chemical methods for the synthesis of NPs.
79 citations
TL;DR: In this article, carboxymethylated gum kondagogu (CMGK) was used as capping and reducing agent by microwave irradiation method to synthesize eco-friendly silver nanoparticles.
Abstract: Eco-friendly silver nanoparticles (AgNPs) were synthesized using a carboxymethylated gum kondagogu (CMGK) as capping and reducing agent by microwave irradiation method. Synthesized AgNPs were analyzed by TEM, showed spherical in shape with an average particle size distribution of 9 ± 2 nm. XRD results showed that the cubic-structured AgNPs with crystallite size of 8.6 nm. The synthesized CMGK capped AgNPs was tested for catalytic activity using hexacyanoferrate(III) in the presence of NaBH4 and the impacts of catalyst dose and temperature were examined. The synthesized AgNPs demonstrated a huge antibacterial action on both Gram-positive and negative groups of microorganisms with inhibition zone of 23, 25 and 28 mm, respectively, for Bacillus subtilis, Bacillus cereus and Escherichia coli, they showed moderate antibacterial action (zone of inhibition 15 mm) with Pseudomonas aeruginosa. In addition, the ability of the AgNPs scavenging activity with different concentrations was studied using the DPPH radical scavenging.
77 citations
TL;DR: In this paper, a nano copper ferrite, CuFe2O4 (CF) is synthesized by one pot energy saving solution combustion synthesis, which is characterized by powder X-ray diffraction, Fourier transform infra-red spectroscopy, scanning electron microscopy, transmission electron microscope, and UV-Vis spectrography.
Abstract: In the present investigation nano copper ferrite, CuFe2O4 (CF) is synthesized by one pot energy saving solution combustion synthesis. The combustion derived copper ferrite nanoadsorbent is characterized by powder X-ray diffraction, Fourier transform infra-red spectroscopy, scanning electron microscopy, transmission electron microscopy and UV–Vis spectroscopy. The magnetic behavior is studied by Vibrating sample magnetometer measurements and the results shows it’s a soft ferromagnet with low saturation magnetization and coercive effect. CF nanopowder is used as good magnetically separable nanoadsorbent. Adsorption property is evaluated by the removal of malachite green, a dye which is widely used by many industries, from its aqueous solution. Various parameters like contact time (5–30 min), adsorbent loading (0–45 mg) are investigated systematically by batch experiments. Adsorption isotherms and kinetic studies also conducted which shows that the adsorption follows pseudo second order mechanism. The experimental data fitted well with the Langmuir isotherm (R
2 = 0.978), yielding a maximum adsorption capacity of 22 mg/g. The optimum adsorbent dose was found to be 40 mg/L and stirring time experiment reveals that 85% of decolourization was observed for 30 min of stirring at neutral pH which is much more efficient than those reported in literature.
72 citations
TL;DR: In this paper, a photocatalytic degradation of eosine blue (EB) dye by cobalt oxide nanocatalyst was carried out, and the optimum conditions for the removal of the EB dye were initial concentration 40 mg/L, photocatalyst dose 0.8 g/L and pH 7.5.
Abstract: The present work deals with the synthesis of cobalt oxide, and Fe2+- and Ni2+-doped cobalt oxide nanoparticles as a catalyst. The study is investigating the different factors in obtaining cobalt oxide, and Fe2+- and Ni2+-doped cobalt oxide nanoparticles. Photocatalytic degradation studies are carried out for water-soluble eosine blue (EB) dye using cobalt oxide, and Fe2+- and Ni2+-doped cobalt oxide nanoparticles in aqueous solution. Different parameters such as initial dye concentration, dose of catalyst, contact time and pH have been studied to optimize reaction conditions. It is observed that photocatalytic degradation is a more effective and faster mode of removing EB dye by cobalt oxide, and Fe2+- and Ni2+-doped cobalt oxide nanoparticles than work done before. The optimum conditions for the removal of the EB dye are initial concentration 40 mg/L, photocatalyst dose 0.8 g/L, and pH 7.5. The EDS technique gives the elemental composition of synthesised cobalt oxide, and Fe2+- and Ni2+-doped cobalt oxide nanoparticles. The TEM and XRD studies are carried for morphological feature characteristics of synthesized cobalt oxide, and Fe2+- and Ni2+-doped cobalt oxide nanoparticles. Pseudo-first-order kinetic has been investigated for both pure and doped cobalt oxide catalysts. Almost 95% dye degradation has been observed for doped cobalt oxide nanoparticles. Graphical abstract for photocatalytic degradation of eosine blue dye by cobalt oxide nanocatalyst.
65 citations
TL;DR: Ginger and garlic extracts were used for the preparation of water and ethanolic extracts and their antioxidant and antibacterial activities were evaluated using TEM and UV-Vis spectroscopic analysis as mentioned in this paper.
Abstract: Ginger and garlic plants were used for the preparation of water and ethanolic extracts. The silver, copper, iron and zinc nanoparticles were eco-friendly synthesized using ginger and garlic extracts and their antioxidant and antibacterial activities were evaluated. The growth of nanoparticles was complemented with characterization using TEM and UV–Vis spectroscopic analysis. Transmission electron microscopy revealed the presence of mono-dispersed metals nanoparticles and silver nanoparticles of ginger have the smallest particle size around 10.10–18.33 nm. The investigated samples were evaluated as antibacterial agents against Staphylococcus aureus, Klebsiella pneumoniae, Candida albicans, Bacillus subtilis, Erwinia carotovora and Proteus vulgaris and as antifungal agents against C. albicans. The results of antimicrobial tests indicate that these nanoparticles possess significant activities compared to the results obtained by antibiotic standard. In addition, the total polyphenols, fractionation of phenols, flavonoids by high-performance liquid chromatography systems and antioxidant activity were evaluated. Comparison of the DPPH and ABTS antioxidant results.
TL;DR: In this paper, the authors discussed the magnetic Fe3O4/LDHs nanocomposites synthesis and applications in the photo catalysis, drug delivery and environmental remediation.
Abstract: In view of the previous work on magnetic Fe3O4 nanoparticles-based layered double hydroxides (magnetic Fe3O4/LDHs) as novel photocatalyst, research on this group of composites became one of the most attractive topics of nowadays. The magnetic Fe3O4/LDHs materials are often utilized for environmental remediation and photocatalysis. Hybrids of layered double hydroxides (LDHs) and Fe3O4 MNPs are efficient nanocomposites due to their flexible properties and the excess of composition available for modification. So, critically reviews on the hybrid of the work magnetic Fe3O4/LDHs composite are the first report that efficient nanocomposites because of their flexible properties, energy and time used for separation, reduced consumption of additional materials can result in significant environmental and economic benefits. “The electrostatic interaction between the positively charged LDHs nanocomposites and negatively charged Fe3O4 MNPs is adequate to make the formation of stable self-assembly of the two components”. This review article discussed the magnetic Fe3O4/LDHs nanocomposites synthesis and applications in the photo catalysis, drug delivery and environmental remediation.
TL;DR: In this paper, the chitosan-copper oxide (Chi-CuO) biopolymer nanocomposites were synthesized by a simple green chemistry method using ascorbic acid as a reducing and capping agent.
Abstract: The chitosan–copper oxide (Chi–CuO) biopolymer nanocomposites were synthesized by a simple green chemistry method using ascorbic acid as a reducing and capping agent. The intense peak around 300 nm was observed in the UV–visible spectrum indicating the formation of CuO nanoparticles. The prepared Chi–CuO nanocomposites were characterized using energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD), and Fourier transform-infrared spectroscopy (FT-IR). SEM and XRD pattern showed cubic shape for Chi–CuO nanocomposites with average crystalline size of 17 nm, as calculated using Debye–Scherrer’s formula. The FT-IR spectral studies showed the Cu–O bond formation with chitosan to form nanocomposites. Synthesized nanocomposites showed significant anti-microbial activity against Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli and Penicillium notatum, assayed using the agar well diffusion method. It also showed sporicidal activity against B. subtilis and exhibited effective biofilm-inhibitory activity against B. subtilis (69%/100 μg/mL) and P. aeruginosa (63%/100 μg/mL).
TL;DR: In this paper, NiFe2O4/hydroxyapatite/graphene quantum dots were synthesized as nano-adsorbent to remove cadmium (Cd2+) from aqueous solution.
Abstract: In this study, NiFe2O4/hydroxyapatite/graphene quantum dots (NiFe2O4/HAP/GQDs) as nano-adsorbent to remove cadmium (Cd2+) from aqueous solution were synthesized. This nano-adsorbent was depicted by some techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR). Adsorption studies were conducted to investigate the effect of contact time, pH, adsorbent dosage and initial cadmium ion concentration on removal efficiency. To determine the most fitting kinetic model, the suitability of pseudo-first-order and pseudo-second-order models was compared. The adsorption isotherm was described well by the Langmuir isotherm and maximum equilibrium uptake capacity (qe) was 344.83 mg g−1. Studies revealed that adsorption process is not a physical process and formation of complexes (bidentate and monodentate complexes) between—COO− and—OH functional groups on the surface of NiFe2O4/HAP/GQDs and Cd2+ ions may occur. In addition, the adsorbent can simply be removed by an ordinary filtration process.
TL;DR: In this paper, MWCNT-COOH-cellulose-MgO NP nanocomposite was used for the removal of methylene 姫blue (MB) dye from aqueous solution.
Abstract: In this work, MWCNT–COOH–cellulose nanocomposite was prepared with MWCNT–COOH, SOCl2 as leaving group and cellulose as an adsorbent (A1); MgO nanoparticles have been successfully coated on the surface of nanocomposite by directly adding to A1 (MWCNT–COOH–cellulose–MgO; A2), magnesium nitrate was added to A1 and MgO nanoparticles were achieved by coating indirectly on the surfaces (MWCNT–COOH–cellulose–MgO; A3). These nanocomposites (A1, A2, and A3) were used for the removal of methylene
blue (MB) dye from aqueous solution. For characterization of adsorbent surfaces, the FT-IR, TEM, SEM, and XRD analysis were used. The effects of initial concentration of MB dye, contact time, and temperature on the adsorption were studied. According to the results, 55 min was selected as the optimum contact time for the removal process. The equilibrium data of adsorption were well fitted and the Langmuir (type III) model had the best agreement because it possesses high value of linear regression, high value R2, and least value of average relative error, ARE (%). Parameters of thermodynamics including enthalpy (∆H°), entropy (∆S°), and Gibbs energy (∆G°) were calculated. Kinetic data had best agreement with pseudo-second-order model. Schematic synthesis of MWCNT–COOH–cellulose–MgO NP nanocomposite as adsorbent
TL;DR: In this paper, a green synthesis of metallic nanoparticles by means of renewable bioresources has emerged as a new trend in current nanotechnology research with improved environmental safety in the current research.
Abstract: Green synthesis of metallic nanoparticles by means of renewable bioresources has emerged as a new trend in current nanotechnology research with improved environmental safety In the current study, monodispersed gold nanoparticles (AuNPs) with excellent stability were prepared in a completely green and cost effective manner using aqueous extract of marine macroalgae-Padina tetrastromatica The influence of reaction conditions such as the quantity of seaweed extract, temperature, precursor metal ion concentration, reaction time and pH on the biosynthesis of nanoparticle was evaluated spectroscopically and also with the help of high resolution transmission electron microscopy (HR-TEM) These physicochemical parameters not only affected the rate of formation but also the size and morphology of resultant nanoparticles Optimum conditions resulted in the generation of nearly spherical AuNPs having an average particle size of 114 nm The high crystallinity of the biogenic AuNPs was confirmed from characteristic diffraction peaks in XRD profile, clear lattice fringes in the HR-TEM image and bright circular spots in the SAED pattern The presence of metallic gold was evidenced from EDAX profile FTIR study revealed the role of secondary metabolites in the bioreduction as well as stabilization of AuNPs The study also highlights the spectroscopic investigation on the catalytic efficacy of the biosynthesized AuNPs in the reduction reactions of hazardous organic dyes, eosin yellow and Congo red using sodium borohydride, which have a pseudo-first order kinetics Thus, the biosynthesized metal nanoparticles using renewable marine resources like seaweeds act as promising materials for the application in environmental protection
TL;DR: In this paper, the photocatalytic activity of nanoparticles prepared via GCR and CCR showed 96 and 83% sunlight degradation of Malachite green (MG) dye, respectively.
Abstract: CuFe2O4 nanoparticles (CNPs) with cubic and tetragonal spinel structures were synthesized by Jatropha oil-assisted green combustion route (GCR) and urea-assisted chemical combustion route (CCR) and well-characterized. The photocatalytic activity of CNPs prepared via GCR and CCR showed 96 and 83% sunlight degradation of Malachite green (MG) dye, respectively. Electrochemical properties of CNPs were studied by means of Cyclic Voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The current research work pledges to provide some novel insights into the design of material for multifunctional long-term applications for environmental clean-up.
TL;DR: In this article, a combination of gamma irradiation, methanol and TiO2 nanoparticles under different pH values was used to achieve an efficient treatment process of effluents containing 1mM copper (Cu2+) and cadmium (Cd2+) ions.
Abstract: Heavy metal pollution has become one of the most serious environmental problems. The aim of this study was to achieve an efficient treatment process of effluents containing 1 mM copper (Cu2+) and cadmium (Cd2+) ions using a combination of gamma irradiation, methanol and TiO2 nanoparticles under different pH values. The results showed that in acidic conditions, removal of Cu2+ and Cd2+ ions by physical adsorption was less than 15% and adsorption of Cd2+ was more than that of Cu2+. In the same condition, the Cu2+ removal percentage by irradiation was greater than that of Cd2+. In basic solutions, due to precipitation of Cd and Cu hydroxides, it was not possible to carry out adsorption experiments on Cd2+ and Cu2+ ions removal by TiO2 and gamma irradiation. Cu2+ and Cd2+ ions removal processes under different conditions could be depicted by the first order kinetics model. The combined application of TiO2 and methanol enhanced Cu2+ and Cd2+ ions removal at all pH levels examined. However, using the combination of TiO2 and methanol at acidic solutions facilitated completely removal of Cu2+ and Cd2+ ions. So that, only using 50 kGy irradiation dose with combination of TiO2 nanoparticles and methanol led to the removal of 99% of coexisting Cu2+ and Cd2+ ions from the acidic wastewater.
TL;DR: In this paper, a simple, cheap, eco-friendly synthesis of the silver nanoparticles (S-AgNPs) using Symphytum officinale leaf extract was demonstrated.
Abstract: The present study demonstrated the simple, cheap, eco-friendly synthesis of the silver nanoparticles (S-AgNPs) using Symphytum officinale leaf extract. The biosynthesized S-AgNPs were characterized by UV–Vis, FE-TEM, elemental mapping, EDX, zeta potential, XRD, SAED, and FT-IR. The characterization results revealed the irregular shape and relatively stable nature of synthesized S-AgNPs. The average particle size was determined to be 87.46 nm. The zeta potential shows the negative surface charge (− 25.5 mV) of S-AgNPs. After characterization, we investigated the anti-aging effect of S-AgNPs in HaCaT keratinocyte cells. HaCaT keratinocyte cells were treated with S-AgNPs at concentrations 1, 10, 100 μg mL−1 after UVB or non-UVB irradiation. The S-AgNPs significantly inhibited the production of matrix metalloproteinase-1 and IL-6 but increased the expression of procollagen type 1. The data suggest that S-AgNPs have photoprotective properties and may have potential to be used as an agent against photoaging.
TL;DR: In this paper, 10-day-cultured BC pellicles were immersed in various citric acid solutions (as bridging agent) and cured at 160°C for 5min.
Abstract: Bacterial cellulose (BC) is a three-dimensional interconnected network of biosynthesized nanofibers. Its rehydration potential would be reduced significantly after its first drying, as a result of entanglement and jamming of cellulose polymer chains. Consequently, its versatility would be also reduced to some limited applications in which repeated water absorbance potential is not of great importance. This study aims to prevent the drawback of carboxylic bridging/cross-linking between cellulose polymer chains. Ten-day-cultured BC pellicles were immersed in various citric acid solutions (as bridging agent) and cured at 160 °C for 5 min. The formation of bridges was confirmed using attenuated total reflection–fourier transform infrared spectroscopy. Scanning electron microscope images showed that there is a different porosity bridged/cross-linked BC specimens (XBC). According to Brunauer–Emmett–Teller analysis, the surface area of XBC (20 w/v % with catalyst) got 87.5 times larger than that of the unbridged/pristine BC (PBC). X-ray diffraction patterns showed no change of crystallinity of XBC in comparison with PBS. The thickness and wettability of XBC samples were 137 and 3.27 times more than PBC samples orderly. Furthermore, the water swelling rate increased significantly for XBC in comparison with PBC. Meanwhile, treated samples had lower elongation and strength than normal BC. The conclusion is that XBC could conserve its repeated absorbency potential after the presented process.
TL;DR: In this paper, a novel S-doped Fe2O3/C nanocomposite was synthesized via a one-pot hydrothermal method and was used for the first time as an efficient adsorbent for Congo red dye (CR) removal from water solution.
Abstract: Novel S-doped Fe2O3/C nanocomposite was synthesized via a one-pot hydrothermal method and was used for the first time as an efficient adsorbent for Congo red dye (CR) removal from water solution. The obtained catalyst was characterized by various methods including Fourier transform infrared spectroscopy, energy dispersive X-ray spectrometry, vibration sample magnetometry, X-ray diffraction and field emission scanning electron microscopy. To improve the adsorption performance, some important parameters affecting dye removal were optimized such as adsorbent dosage, contact time, solution pH, initial dye concentration and ionic strength. At the optimum conditions, the maximum capacity of adsorption for this nanocomposite was 270.2 mg g−1, which is better than other magnetic adsorbents for CR removal. The results of adsorption isotherm were matched with Langmuir model. Kinetic tests show that adsorption experimental data were best fitted by pseudo-first-order model.
TL;DR: In this article, super-paramagnetic iron-oxide nanoparticles (SPIONs) were synthesized using environmentally accepted green synthesis process where Azadirachta indica leaf extract was used as one of the reducing agents along with basic metal precursors used in chemical processes.
Abstract: Super-paramagnetic iron-oxide nanoparticles (SPIONs) have been exploited from a very long time and are researched profoundly due to their unique properties In this study, SPIONs were synthesized using environmentally accepted green synthesis process where Azadirachta indica leaf extract was used as one of the reducing agents along with basic metal precursors used in chemical processes The synthesized SPIONs were characterised using microscopic analysis (SEM, TEM, and AFM), spectroscopic analysis (FT-IR, UV–Vis, XRD, Raman, and zeta potential), and magnetometry (SQUID) The SPIONs were then tested for its application in the removal of heavy metals from tannery waste water and also X-ray imaging
TL;DR: In this article, the aqueous extract of Tarragon, as a reducing agent, was used to synthesize silver-montmorillonite (MMT) nanocomposite (Ag-MMT-NPs) in the batch method.
Abstract: The aqueous extract of Tarragon, as a reducing agent, was used to synthesize silver–montmorillonite (MMT) nanocomposite (Ag–MMT-NPs) in the batch method. The leaf extract and metal solution concentrations were optimized to improve Ag–MMT-NPs synthesis in 48 h. For characterizing the nanocomposite, powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), and UV–Vis spectroscopy were performed. The peak was observed at 437 nm on the UV–Vis spectrum, showing the surface plasmon resonance of Ag–MMT-NPs. Using XRD analysis, the crystalline nature and purity of Ag–MMT-NPs were confirmed. FTIR was used to evaluate specific functional groups, causing a reduction in silver nitrate during Ag–MMT-NPs formation. According to TEM, the average particle size was 25.12 nm in AgNPs. The nanocomposite showed antibacterial properties against Gram-negative and Gram-positive bacteria (Escherichia coli and Staphylococcus aureus).
TL;DR: In this paper, aqueous extract of the bark of Terminalia arjuna was utilized to synthesize T.Arjuna-conjugated palladium nanoparticles (TA-PdNPs) from palladium chloride.
Abstract: Synthesis of metal nanoparticles from the metal salts by reduction with plant extracts in water, without any additional stabilizing or capping agents is a green and eco-friendly method. In the present work, aqueous extract of the bark of Terminalia arjuna was utilized to synthesize T. arjuna-conjugated palladium nanoparticles (TA-PdNPs) from palladium chloride. The dark brown colour indicating the formation of TA-PdNPs appeared within 3 h without heating but, on heating colour appeared almost instantly. The synthesized TA-PdNPs are characterized by UV spectroscopy, HRTEM and XRD studies. The TA-PdNPs were utilized as efficient catalyst for Heck and Suzuki type C–C coupling reactions and degradation of organic dyes in aqueous medium at room temperature.
TL;DR: In this article, facile, rapid biosynthesis and characterization of silver-montmorillonite (MMT) nanocomposite is carried out at ambient temperature by using water extract of Satureja hortensis (L) as reducing agent and MMT as interlamellar space for controlling the size of Ag-NPs.
Abstract: In this project, facile, rapid biosynthesis and characterization of silver–montmorillonite (MMT) nanocomposite is carried out at ambient temperature. Silver nanoparticles (Ag-NPs) were prepared by water extract of the plant [Satureja hortensis (L)] as the reducing agent and MMT as interlamellar space for controlling the size of Ag-NPs. MMT was sonicated in the aqueous AgNO3 solution and Ag+ ions were reduced to Ag° using water extract of Satureja hortensis (L). The nanocomposite was evaluated using ultraviolet–visible spectroscopy (UV–Vis), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). TEM study showed the formations of nanocomposite using water extract of Satureja hortensis L in the range of 4.88–26.70 nm and an average particles size of 15.79 nm. In addition, XRD studies indicated that the particles have a face centred cubic (FCC) structure. The nanocomposite showed antibacterial effects against bacteria.
TL;DR: In this paper, the effect of calcination temperature on the structure and performance of mesoporous CaO/TiO2-ZrO2 catalyst fabricated by sol-gel method used in the esterification reaction was assessed.
Abstract: In the present study, the effect of calcination temperature on the structure and performance of mesoporous CaO/TiO2–ZrO2 catalyst fabricated by sol–gel method used in the esterification reaction was assessed. Then, CaO/TiO2 catalyst was also synthesized via the same method to evaluate the effect of zirconia cations on its properties and activity. The samples were characterized by X-ray Diffraction (XRD), Fourier transmittance infra-red (FT-IR), Brunauer–Emmett–Teller (BET)–Barrett-Joyner-Halenda (BJH), scanning electron microscope (SEM) and transmission electron microscopy (TEM) analyses. Moreover, Hammett indicator method was utilized to assess the acidity and basicity of the samples. It was found that zirconium was clearly incorporated in CaO/TiO2 lattice and transformed that from amorphous phase to crystalline structure. In addition, the basicity and acidity of CaO/TiO2 was clearly increased by zirconia loading. Evaluation of the samples’ activity presented that CaO/TiO2 catalyst exhibit no activity in the esterification reaction, while all CaO/TiO2–ZrO2 catalysts showed high ability to convert oleic acid to its ester. Moreover, the catalyst calcined at 400 °C showed the highest activity in the esterification reaction with desirable properties such as high crystallinity, acidity, basicity and surface area along with well-distribution of particle size and pore size. The best catalyst converted around 90% of oleic acid to ester at optimized conditions of 150 °C, 12:1 molar ratio of methanol/oleic acid, 3 wt% of catalyst for 4 h of reaction time. Moreover, the sample was successfully used for five runs without significant reduction in activity that makes it a suitable choice as a catalyst for industrial applications.
TL;DR: In this article, a simple and low-cost procedure for synthesis of graphene nanosheets (GNSs) is derived from aqueous suspension of graphene oxide (GO), and structural and morphological characterization indicates the absence of oxygenbearing groups from graphene oxide.
Abstract: To address the environmental concerns, a relatively simple, innovative and low-cost procedure has been suggested for synthesis of graphene nanosheets (GNSs). The procedure utilized here for synthesizing GNSs is derived from aqueous suspension of graphene oxide (GO). Ficus carica (FC) is known to be remarkable antioxidant. It is regarded as suitable biocompatible alternative to hazardous and toxic chemicals. This method ensures non-hazardous nature of the deoxygenating agent (FC) as well as their oxidized outcomes. Structural and morphological characterization indicates the absence of oxygen-bearing groups from graphene oxide. Characterization was done by standard techniques such as X-ray crystallography, FTIR, RAMAN, DLS, and UV–Vis spectrophotometry. Morphological investigation of resulting material was also undertaken through standard techniques by FESEM, TEM, HRTEM with SAED pattern. Thermal stability of FC derived graphene was also investigated. The investigation may initiate new routes for preparing GNSs at large scale facilitating a better research and commercial utilization.
TL;DR: In this article, boron trifluoride supported on coconut shell nano-particles (nano-BF2O-coc) was prepared from nano-crystalline coconut shell through mechanical method using ultrasonication.
Abstract: In this paper, boron trifluoride supported on coconut shell nano-particles (nano-BF2O-coc) was prepared from nano-crystalline coconut shell through mechanical method using ultrasonication. The resultant was utilized to obtain nano-crystalline BF3 supported on coconut shell nano-particles (nano-BF2O-coc). The novel nanostructure has been characterized using Fourier transform infrared spectroscopy, transmission electron microscopy, field-emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy (EDX) techniques. The catalytic activity of the solid acid catalyst has been successfully examined in a one-pot, three-component condensation reaction of barbituric acid, ethyl cyanoacetate or malononitrile, and aldehydes in refluxing ethanol to furnish pyrano[2,3-d]pyrimidine derivatives.
TL;DR: In this article, a facile method for the production of Antibacterial and Antistatic polyurethane coatings was investigated using copper modified ZnO nanoparticles-polyaniline nanofibers (PANI-CuZnO) ternary nanocomposite.
Abstract: In this study, a facile method for the production of Antibacterial and Antistatic polyurethane coatings was investigated using copper modified ZnO nanoparticles–polyaniline nanofibers (PANI–CuZnO) ternary nanocomposite. PANI–CuZnO ternary nanocomposite was synthesized through two steps. First, copper-modified ZnO nanoparticles were produced through the hydrolysis method using acetate precursors, and then they were mixed with polyaniline nanofibers, which were synthesized by seeding method. The obtained nanocomposite was characterized by FTIR, XRD, and FESEM techniques. Results of evaluating the antibacterial action of the polyurethane coatings with the content of ternary nanocomposite showed that the obtained coatings have a proper antibacterial action against Gram-positive and Gram-negative bacteria. In addition, measuring the coatings’ surface electrical resistance revealed that addition of the ternary nanocomposite to the polyurethane coatings’ matrix causes the surface electrical resistance of the coatings significantly decreases and reaches 8 × 107 Ω/sq. Thereby, they could be categorized as an antistatic coating. Moreover, the addition of PANI–CuZnO enhanced adhesion strength and scratch resistance of the final polyurethane coatings.
TL;DR: In this paper, the effect of the presence of four surfactants, namely cocamidopropyl betaine (CAPB), decylglycoside (DG), cetyltrimethyl ammonium chloride (CTAC) and ammonium lauryl ether sulfate (ALES), on Ni-SiO2 composite was investigated.
Abstract: This article presents a method for the electrochemical preparation of a coating of nickel–silica nanocomposites on a carbon steel substrate. The incorporation of hydrophilic silica particles into the Ni composite coating during co-electrodeposition is so difficult due to the small size and the hydrophilicity of SiO2 particle, generally less than 2 v% of silica is incorporated into the composite at different current densities, agitation speeds and silica concentrations. The effect of the presence of four surfactants, namely cocamidopropyl betaine (CAPB), decylglycoside (DG), cetyltrimethyl ammonium chloride (CTAC) and ammonium lauryl ether sulfate (ALES), on overcoming this problem was investigated in this research, and the surfactants were found to greatly influence the surface charge of silica, silica incorporation percentage and the microstructure of the composite. In fact, upon increasing the internal stresses, the products prepared in the presence of CAPB and DG were found to crack to some degree. CTAC was found to lead to entrapment mode silica co-deposition in the Ni coating. Furthermore, the addition of ALES into an electrolyte bath negatively supercharged silica surfaces and increased silica dispersion, which led to a dramatic increase in the silica incorporation percentages to around 14 v%. The results showed that Ni–SiO2 composites prepared in the presence of ALES had better corrosion resistance, hardness and wear properties.