Green synthesis of copper oxide nanoparticles CuO NPs from Eucalyptus Globoulus leaf extract: Adsorption and design of experiments

The study is concerned with synthesizing copper oxide nanoparticles with leaf extract Eucalyptus Globoulus. The results of scanning electron microscopy (SEM) and dynamic light scattering (DLS) revealed that the green synthesized copper oxide nanoparticles are spherical and have a mean particle size of 88 nm, with a negative zeta potential of ?16.9 mV. The XRD graph showed the crystalline and monoclinic phases of CuO nanoparticles. The average crystalline size around 85.80 nm was observed by the Debye–Scherrer formula. The adsorption characteristics of the nano-adsorbents were investigated using methyl orange, and the adsorption efficiency at room temperature attained 95 mg/g. Copper oxide nanoparticles (CuO NPs) adsorb methyl orange dye most effectively at pH 4.5 when the dye is applied in quantities of 0.04 g/50 mL. Box–Behnken design (BBD) in response surface methodology (RSM) was used to optimize various process parameters, such as pH solution (X₁: 2 – 11), adsorbing dose (X₂: 0.01 – 0.08 g/L), [MO] dye concentration (X₃: 10 – 80 mg/L). Overall, the adjusted coefficient of determination (R²) value of 0.99 demonstrated that the used model was quite appropriate, and the chosen RSM was effective in optimization the decolorization conditions of MO.     

Fabrication of magnetite nanoparticles (Fe3O4-NPs) for catalytic pyrolysis of nutshells biomass

The fabrication of nanoparticles has been perused as a topic of critical importance in the present decades. Biosynthesis of nanoparticles employs plants extract instead of harmful chemicals. These plant extracts act as reducing and capping agents which is the most appropriate and eco-friendly method among all the preparative routs. In present study, the magnetite nanoparticles (Fe₃O₄-NPs) were fabricated using rapid, single step and benign biosynthetic rout by reduction of ferric nitrate nonahydrate solution with Ferocactus echidne aqueous extract containing ascorbic acid as a main reducing and capping agent. The structural and morphological properties of prepared iron oxide nanoparticles were investigated by Powder X-ray diffraction and scanning electron microscopy. The size of the synthesized nanoparticles was approximately 15 ± 2 nm as determined by Scherrer equation. The biosynthetically fabricated nanoparticles were employed as catalyst for pyrolysis of nutshells to produce biofuel. Catalytic pyrolysis of biomass yields biofuel as an alternative source of energy and chemical feed stock. Effect of temperature, heating rate, and amount of catalyst were investigated on conversion percentage and product yields. Aniline point, carbon residue, and cetane number of prepared bio-oil were also determined.     

Facile synthesis and antibacterial activity of silver nanoparticles-modified graphene oxide hybrid material: the assessment,utilization, and anti-virus potentiality

The present work reported the one-pot preparation of silver nanoparticles doped with graphene oxide (Ag@GO), using glucose as an eco-friendly reducing agent. The effects of synthesis conditions on the introduction of AgNPs onto graphene oxide sheets were confirmed by modern analytical techniques and antibacterial assays. Results showed that the Ag@GO-4 sample prepared with glucose:AgNO₃:GO mass ratio of 1:1:1 at 60 °C for 60 min exhibited an appropriate one for further studies with AgNPs sizing of 16.66 ± 3.73 nm. The Ag@GO-4 effectively inhibited the development of S. enterica, P. aeruginosa, and S. aureus with the 50 % inhibitory concentration at 14.5, 0.9, and 6.8 μg/mL, respectively. The simultaneous effects of Ag@GO concentration, pH, interaction time, annealing temperature, and bacterial density on the antibacterial activity of Ag@GO-4 were also investigated by Plackett-Burman and Box-Behnken design. The optimal values deducing for Ag@GO-4 concentration, pH, and bacterial density were 40 μg/mL, 5.5, and 5.1 × 10⁶ CFU/mL, respectively, which could impressively reach 99.99 % of S. enterica elimination in practice. The interaction time and annealing temperature implied a negligible effect on the antibacterial activity of Ag@GO-4. All results of the present study affirmed the future use of Ag@GO not only as an efficient antibacterial agent but also potentially as a novel anti-virus method of treatment.     

Size and stability modulation of ionic liquid functionalized gold nanoparticles synthesized using Elaeis guineensis (oil palm) kernel extract

Bio-synthesis approach for gold nanoparticles (AuNPs) has received tremendous attention as an efficient and eco-friendly process. However, kinetic growth and colloidal stability of AuNPs synthesized by this process remained challenging. In this study, Elaeis guineensis (oil palm) kernel (OPK) extract prepared in an ionic liquid (IL)[EMIM][OAc] (1-ethyl-3-methylimidazolium acetate) was employed to control and tune the size and morphology of AuNPs. Synthesized AuNPs were characterized using UV-vis spectrophotometer, dynamic light scattering (DLS) and transmission electron microscopy (TEM) to observe any changes in absorbance, surface charge and particle size, respectively. IL mediated AuNPs were examined for 120 days and found well dispersed and stable at room temperature. UV-vis analysis demonstrated that volume of extract played an important role to control the stability of AuNPs. After 120 days, only 8.86% reduction from maximum absorbance was observed using 2 mL of volume of extract, which was elevated to 47.64% in case of 0.3 mL. TEM analysis was performed periodically after day 1, day 30, day 60, day 90 and day 120 and minor increase in the size was observed. Insignificant change in zeta potential value after 120 days supported enhanced stability of IL mediated AuNPs. Crystalline nature of AuNPs was confirmed by X-ray diffraction (XRD) pattern. The particles size and zeta potential of AuNPs was measured as 8.72 nm and −18.7 mV, respectively. However, the absence of [EMIM][OAc] from OPK extract resulted into larger particles size (9.64 nm), low zeta potential value (−13.9 mV) and enhanced aggregation of particles. Finally, experimental data were used to predict the theoretical and the experimental settling time for AuNPs to evaluate colloidal stability.     

Preparation and biological evaluation of radiolabeled-folate embedded superparamagnetic nanoparticles in wild-type rats

In this study, superparamagnetic iron oxide nanoparticles (SPION) embedded by folic acid (SPION-folate) were prepared by a modified co-precipitation method. The structure, size, morphology, magnetic property and relaxivity of the SPION-folate were characterized systematically by means of XRD, VSM, HRSEM and TEM and the interaction between folate and iron oxide (Fe₃O₄) was characterized by FT-IR. The particle size was shown to be ≈5–10 nm. To ensure biocompatibility, the interaction of these SPION with mouse connective tissue cells (adhesive) was investigated using an MTT assay. Consequently, gallium-67 labeled nanoparticles ([⁶⁷Ga]-SPION-folate) were prepared using ⁶⁷Ga with a high labeling efficiency (over 96%, RTLC method) and they also showed an excellent stability at room temperature for at least 2 days and were evaluated for their biodistribution in normal rats up to 24 h compared with free Ga³⁺ cation and [⁶⁷Ga]-SPION biodistribution. The biodistribution of the tracer among 3 other folate tracers were compared, showing lower liver uptake and higher blood circulation after 24 h leading to better bioavailability. The bone:muscle, kidney:muscle, lung:muscle, stomach:muscle ratios were 9.3, 9.32, 7.6 and 5.83 respectively. The developed folate-containing nano-system can be an interesting folate receptor tracer, capable of better cell membrane permeability while possessing paramagnetic properties for thermotherapy.     

Facile Biogenic Synthesis and Characterization of Seven Metal-Based Nanoparticles Conjugated with Phytochemical Bioactives Using Fragaria ananassa Leaf Extract

In this investigation, for the first time, we used Fragaria ananassa (strawberry) leaf extract as a source of natural reducing, capping or stabilizing agents to develop an eco-friendly, cost-effective and safe process for the biosynthesis of metal-based nanoparticles including silver, copper, iron, zinc and magnesium oxide. Calcinated and non-calcinated zinc oxide nanoparticles also synthesized during a method different from our previous study. To confirm the successful formation of nanoparticles, different characterization techniques applied. UV-Vis spectroscopy, X-ray Diffraction (XRD) spectroscopy, Field Emission Scanning Electron Microscopy (FESEM) coupled with Energy Dispersive X-ray Spectroscopy (EDS), Photon Cross-Correlation Spectroscopy (PCCS) and Fourier Transformed Infrared Spectroscopy (FT-IR) were used to study the unique structure and properties of biosynthesized nanoparticles. The results show the successful formation of metal-based particles in the range of nanometer, confirmed by different characterization techniques. Finally, the presented approach has been demonstrated to be effective in the biosynthesis of metal and metal oxide nanoparticles.     

Iron hydroxide nanoparticles coated with poly(ethylene glycol)-poly(aspartic acid) block copolymer as novel magnetic resonance contrast agents for in vivo cancer imaging

PEG-coated β-FeOOH nanoparticles were prepared through electrostatic complex formation of iron oxide nanoparticles with poly(ethylene glycol)-poly(aspartic acid) block copolymer [PEG-P(Asp)] in distilled water. By dynamic light scattering (DLS) measurement, the nanopaticle size was determined to be 70 nm with narrow distribution. The FT-IR and zeta potential experimental results proved that PEG-PAsp molecules bound to the surface of the iron oxide nanoparticles via the coordination between the carboxylic acid residues in the PAsp segment of the block copolymer and the surface Fe of the β-FeOOH nanoparticles. The PEG-coated nanoparticles revealed excellent solubility and stability in aqueous solution as well as in physiological saline. In vivo MRI experiments on tumor-bearing mice demonstrated that the PEG-coated nanoparticles prepared by the current approach achieved an appreciable accumulation into solid tumor, suggesting their potential utility as tumor-selective MRI contrast agents.     

Nanotheranostic fabrication of iron oxide for rapid photocatalytic degradation of organic dyes and antifungal potential

This research work includes the fabrication of iron oxide nanoparticles (Fe₂O₃ NPs) by green construction approach using Wisteria sinensis leaves extract. Due to its eco-friendly approach, the synthesis of iron oxide NPs (Fe₂O₃ NPs) using various plant sources, such as plant parts, and microbial cells have gained a lot of attention in recent years. Cost-effectiveness and ease of availability make Wisteria sinensis leaves extract a potential candidate for the construction of iron oxide NPs. The various key features like biocompatibility, non-toxicity capping, and stabilizing agents present in biological sources are advantageous for usage in a variety of applications. The phytoconstituents present in the leaf extract of Wisteria sinensis serve as reducing and stabilizing agents. The biologically fabricated (Fe₂O₃ NPs) were analyzed using FT-IR, XRD, UV–vis spectroscopy, and SEM. In the present work, the antioxidant and photocatalytic dye degradation efficiency of Fe₂O₃ NPs has been studied. The dye degradation efficiency of methylene blue dye was found to be 87% at 180 min upon exposure to sunlight. The capacity of Fe₂O₃ NPs to scavenge 2,2-diphenyl-1-picrylhydrazyl hydrate free radicals (DPPH) was examined using a UV–Vis spectrophotometer. The study compared the radical scavenging activity (RSA) of Fe₂O₃ nanoparticles (NPs) with that of the standard antioxidant ascorbic acid. The results demonstrated that Fe₂O₃ NPs have a greater ability to scavenge radicals than ascorbic acid. The half-maximal inhibitory concentration (IC50) of Fe₂O₃ NPs was observed to range from 0.12 to 0.17. Furthermore, Fe₂O₃ NPs displayed the highest antifungal activity, with an inhibition zone of 26.8 mm against F. oxysporum. These findings suggest that the biologically synthesized Fe₂O₃ NPs possess potent antimicrobial and dye degradation properties.     

Biosynthesis,characterization, biological and photo catalytic investigations of Elsholtzia blanda and chitosan mediated copper oxide nanoparticles

Bio synthesis of nanoparticles using plant parts has gained considerable attention, given the fact that the method is green, environment friendly, cheaper, simple and involves no hazardous substances. The present study involves the green synthesis of copper oxide nanoparticles (CuO NPs) using chitosan and the aqueous leaf extract of Elsholtzia blanda, an aromatic medicinal herb. The synthesized E.blanda-chitosan mediated copper oxide nanoparticles (CPCE) and E. blanda mediated copper oxide nanoparticles (PCE) were subjected to different characterization techniques, Ultraviolet–visible (UV–Vis), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive X-ray Analysis (EDAX), High Resolution Transmission Electron Microscopy (HRTEM) and Selected Area Electron Diffraction (SAED). The absorbance peaks in UV–Vis spectroscopy at 286 nm and 278 nm for CPCE and PCE respectively indicated the formation of nanoparticles. TEM and SEM employed for studying the surface morphology showed rod-like and spherical morphology bearing average size of 47.71 nm for CPCE and 36.07 nm for PCE. The antibacterial activities of the prepared nanoparticles were tested against Enterococcus faecalis, Staphylococcus aureus, Escherichia coli and Salmonella typhi by agar well diffusion method. The results indicate that CuO NPs possess effective antibacterial potential against all tested bacteria with a maximum zone of inhibition of 18 mm for Enterococcus faecalis. Antioxidant studies revealed the highest DPPH scavenging activity of 89% at 25 μg/mL concentration of the nanoparticles. The percentage of the photo catalytic degradation of Congo red was found to be 95% after 10 h.     

Preparation and characterization of submicron hybrid magnetic latex particles

Micrometer magnetic hybrid particles are of great interest in biomedical field, and various morphologies have been prepared via encapsulation processes. Regarding submicron, only few processes have been investigated and the most recent one leading to highly magnetic submicron magnetic hybrid particles is based on oil in water magnetic emulsion (MES) transformation. The encapsulation of magnetic iron oxide nanoparticles forming oil in water MES was investigated using different styrene/cross‐linker divinylbenzene volume ratio in the presence of potassium persulfate initiator. The encapsulation performed in this work is basically conducted by using well‐defined oil in water MES as a seed in radical emulsion polymerization. The chemical composition, morphology, iron oxide content, magnetic properties, electrokinetic properties, particle size, and size distribution of the prepared magnetic hybrid particles were examined using various techniques. The desired perfect magnetic core and polymer shell morphology were successfully obtained, and the final magnetic hybrid particles are superparamagnetic in nature and exhibit high iron oxide content (64 wt %). Copyright © 2015 John Wiley & Sons, Ltd.     

Analysis of an Emulsification Process Using Fractional Experimental Design

ABSTRACT

Soy oil-in-water emulsions (30% oil) with soy lecithin as emulsifier (4%) were prepared using a stirred vessel under batch conditions. The effects of 7 process variables (impeller-to-tank diameter ratio, temperature, agitation speed, mode of cooling and also pre-emulsification mixing rate, pre-emulsification mixing time and resting time before emulsification) were studied according to a fractional factorial design 2^7?3. The droplet size distributions of the emulsions were measured and the kinetics of destabilization were monitored during 3 months. In the experimental domain, the mixing rate was found to be the most significant variable affecting both the size distribution and the stability. It was followed by the temperature, and the impeller-to-tank ratio depending on the Sauter mean diameter or the half-life time of the emulsions. Interaction of the temperature with the agitation speed and with the impeller-to-tank diameter ratio was also observed.     

Green synthesis and characterization of Fe doped ZnO nanoparticles and their interaction with bovine serum albumin

Herein we report an eco-friendly and cost efficient synthesis of Fe doped ZnO (TPFZO) nanoparticles using the extract of Thespesia polpulanea flowers as a stabilizing agent. The synthesized NPs have been characterized by XRD, FT-IR, UV-DRS, SEM, EDAX and TEM studies. The synthesized NPs were found to have the crystallite size in the range of 30–60 ​nm. The calculated band gap energies for ZO and TPFZO nanoparticles were 3.00 ​eV and 1.97 ​eV respectively. The size distribution of the ZO and TPFZO obtained from TEM were observed to be lying in the range 50–120 ​nm and 4–22 ​nm respectively. The interaction of TPFZO NPs with bovine serum albumin (BSA) has been studied using fluorescence and absorption titration methods. The results indicated that the nanoparticles quenched the BSA fluorescence at 340 ​nm via static quenching mode having a bimolecular quenching rate constant value of 6.21 ​× ​10¹³ Lmol⁻¹s⁻¹.     

Analysis of hydrocarbon contamination with membrane-assisted solvent extraction: Comparison of agitation and sonication methods

Membrane-assisted solvent extraction (MASE) coupled to large volume injection was applied to the determination of (gasoline-type) hydrocarbon contamination in water samples. Hexane was used as acceptor phase. 50 μL extract was injected in the programmed temperature vaporizer injector using combined split–splitless evaporation. The extraction conditions were optimized both for MASE with agitation and for MASE with sonication. In the course of optimization the effect of extraction time, extraction temperature, agitation speed, solvent volume, pH, ionic strength and the addition of methanol were tested. Over 75% recovery was accomplished in the range of diesel oil hydrocarbons (n-C₉–n-C₂₄). The developed method was validated. Linearity, accuracy and precision were tested. The method showed excellent linearity between 1 and 1000 μg L^?1 for n-alkanes and between 0.05 and 50 mg L^?1 for gasoline. The method was tested with comprehensive GC × GC as well and found to be non-discriminative to all major compounds of diesel oil.     

In vivo biodistribution,antioxidant and hemolysis tendency of superparamagnetic iron oxide nanoparticles – Potential anticancer agents

Ferromagnetic and superparamagnetic oxide nanoparticles are of particular attention because of their possible use in various fields ranging from bio-nanotechnology to spintronics. Detailed magnetic, dielectric and impedance investigations are crucial for the above-mentioned applications. This study deals with the exploration of various iron oxide phases under as-synthesized conditions by sol–gel method. pH of the sols is varied in the range of 1 to 11. X-ray diffraction (XRD) analysis indicate amorphous behavior for nanoparticles synthesized using pH 1 and 3. Nanoparticles synthesized using pH 2 and 4–6 exhibit hematite phase of iron oxide. Whereas structural transition to maghemite phase is observed for pH 7–8. Nanoparticles synthesized using high pH values, i.e. 9–11, exhibit structural transition towards magnetite phase of iron oxide. Hematite nanoparticles exhibit superparamagnetic and ferromagnetic hysteresis curves with saturation magnetization of ～ 24 emu/g and ～ 13–17 emu/g at pH 2 and pH 4–6, respectively. Maghemite nanoparticles exhibit superparamagnetic (pH 7) and ferromagnetic (pH 8) response with saturation magnetization of ～ 69 and ～ 42 emu/g, respectively. Fe₃O₄ nanoparticles exhibit superparamagnetic (pH 9–10) and ferromagnetic (pH 11) behavior with saturation magnetization of ～ 88, 87 and 52 emu/g, respectively. High grain boundary resistance contributed towards high dielectric constant of ～ 99, 109 and 154 (log f = 5.0) at pH 2, 7 and 9. Detailed impedance values indicate dominant role of grain boundaries in the conductivity of iron oxide nanoparticles. Superparamagnetic iron oxide (pH 9) exhibits strong antioxidant activity along with a very weak hemolytic response. The findings of cell lysis reveal that synthesized nanoparticles have a potential to combat dangerous cancer cells. Drug efficacy results show that after 120 min the encapsulation efficacy reaches a peak of ～ 83 % using curcumin, a naturally existing drug. In vivo biodistribution of nanoparticles was studied in Rabbit model. Synthesized nanoparticles are labelled using Technetium-99 m. Whereas, labeling efficacy and stability was examined using =nstant thin layer chromatography (ITLC) process. In vitro and in vivo results suggest potential anti-cancer applications of as-synthesized superparamagnetic nanoparticles.     

In-vitro hemolytic activity and free radical scavenging by sol-gel synthesized Fe3O4 stabilized ZrO2 nanoparticles

Zirconia ceramics have attained much consideration owing to the amazing mechanical strength and white color. These properties provide an opportunity for the use in biomedical applications. In the present study, an application oriented sol-gel route was adapted for synthesis of zirconia nanoparticles. ZrOCl₂·8H₂O was used as a precursor, iron oxide (Fe₃O₄) nanoparticles (pH 2 & pH 9) as a stabilizer and de-ionized water was used as a solvent. Sol-gel synthesized iron oxide stabilized zirconia nanoparticles were prepared by varying concentrations of iron oxide nanoparticles in the range of 2–10 wt%. X-ray diffraction results showed mixed phases at all wt% with acidic pH value, while pure tetragonal phase of zirconia was observed for stabilization with 6 wt% basic iron oxide. Maximum value of dielectric constant (~80 at log f = 4) and minimum value of tangent loss (~0.66 at log f = 4) were observed for zirconia stabilized with basic 6 wt% iron oxide. Maximum value of hardness (1410 ± 10 HV) along with high fracture toughness were observed with optimized stabilization. Very weak hemolytic activity and maximum scavenging (~76) antioxidant activity was observed under optimized conditions. Thus, it can be suggested that optimized nanoparticles, i.e. tetragonal zirconia stabilized with 6 wt% of basic Fe₃O₄, can be further useful for therapeutical and pharmaceutical applications.     

Biosynthesis of Au nanoparticles using olive leaf extract: 1st Nano Updates

The biological synthesis of gold nanoparticles (AuNPs) of various shapes (triangle, hexagonal, and spherical) using hot water olive leaf extracts as reducing agent is reported. The size and the shape of Au nanoparticles are modulated by varying the ratio of metal salt and extract in the reaction medium. Only 20 min were required for the conversion into gold nanoparticles at room temperature, suggesting a reaction rate higher or comparable to those of nanoparticles synthesis by chemical methods. The variation of the pH of the reaction medium gives AuNPs nanoparticles of different shapes. The nanoparticles obtained are characterized by UV–Vis spectroscopy, photoluminescence, transmission electron microscopy (TEM), X-ray diffraction (XRD), FTIR spectroscopy and thermogravimetric analysis. The TEM images showed that a mixture of shapes (triangular, hexagonal and spherical) structures was formed at lower leaf broth concentration and high pH, while smaller spherical shapes were obtained at higher leaf broth concentration and low pH.     

Green biosynthesis,characterization, and cytotoxic effect of magnetic iron nanoparticles using Brassica Oleracea var capitata sub var rubra (red cabbage) aqueous peel extract

The green method of nanoparticle synthesis, which is an environment and living-friendly method, is an updated subject that has appeared as an alternative to conventional methods such as physical and chemical synthesis. In this presented study, the green synthesis of magnetic iron oxide nanoparticles (IONPs) from iron (III) chloride by using Brassica oleracea var. capitata sub.var. rubra aqueous peel extract has been reported. The prepared IONPs were characterized with fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV-VIS), zeta potential, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The cytotoxic effects of IONPs on MCF-7 breast cancer cell line were studied by MTT assay, and migrative effect of its were carried out by the wound healing assay. It was found that the mean particle size of IONPs was 675 ± 25 nm, and the polydispersity index was 0.265 PDI. It was also determined that these nanoparticles had an anti-proliferative impact on the MCF-7 breast cancer cell line depending on the dosage. Characterization results support the successful synthesis of nanoparticles, and the dose-dependent cytotoxic effects of nanoparticles on MCF-7 cells also make it a potential chemotherapeutic agent for breast cancer treatment.     

Biogenic synthesis of silver nanoparticles using Echium vulgare: Characterisation,quantitative analysis of bioactive compounds,antioxidant activity and catalytic degradation

Nanotechnology has a great significance owing to its large variety of applications. Silver nanoparticles (AgNPs@Ev) were produced using water extract of Echium vulgare aerial part by a simple, nontoxic, eco-friendly method. The spectroscopic study identified the structure of AgNPs@Ev. The absorption was detected as 460 nm by UV/Vis spectrophotometer. TEM analysis presented the morphology of nanostructures and particle size was calculated as 9.55 nm. XRD pattern showed the structure to be face-centered cubic unit cell. EDS analysis verified the presence of elemental silver. DLS and zeta potential analyses were executed by Zetasizer. The stability of nanostructures was revealed by the zeta potential analysis (−3.1 mV). The degradation performance of AgNPs@Ev on methylene blue was evaluated by UV/Vis spectrophotometer and 64% of methylene blue was degraded after 40 h. Quantitative analysis of natural compounds was performed by HPLC and isoquercitrin (1.32 mg/g extract), naringin (1.15 mg/g extract) were detected as major products. Antioxidant activity of extract and nanoparticles were achieved. AgNPs@Ev exhibited excellent DPPH, ABTS, and FRAP activities (IC₅₀, 6.8 μg/mL), (IC₅₀, 2.3 μg/mL), (5.3 μmol/g sample) respectively.     

Investigation of tannery liming waste water using green synthesised iron oxide nano particles

ABSTRACT

The present study aimed that non-toxic, less expensive, easily available, safer to environment and previously unreported Eclipta prostrata leaf extract is used for the green synthesis of iron oxide nano particles. The iron oxide nanoparticles (NPs) were characterised by UV–visible, Fourier Transform Infrared Spectroscopy (FTIR), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Tannery effluents treated by photodegradation process and the removal efficiency of chemical oxygen demand (COD), biological oxygen demand (BOD) and sulphide were analysed. The maximum removal efficiency correlated with operating parameters was explained using response surface methodology with Boxmen Beckmen design.     

Study the effect of HLB of surfactant on particle size distribution of hematite nanoparticles prepared via the reverse microemulsion

Hematite nanoparticles have been synthesized via reverse microemulsion route at room temperature. The microemulsion system, contained water, chloroform, 1-butanol, and surfactant, was combined with iron nitrate solution to result iron oxide nanoparticles precipitation. Three technical surfactants, with different structures and HLB (hydrophile–lipophile balance) values were employed and the effects of the HLB values on the hematite particle size were investigated. The prepared particles were evaluated by BET, XRD and TEM techniques. These results showed that the iron oxide particle size and particle size distribution increased with increasing surfactant HLB values.