Nanotechnology

The demand for commercial nanoparticles are on the increase due to their wider applications in many fields, the biological synthesis provides a cost-effective, more stable materials using eco-environmental friendly routes to reduce health risk and hazardous waste into the environment. Nanoparticles are products of a rapidly growing technology which is widely applied in many fields. The use of toxic organic solvents and strong reducing agents are not environmental friendly which results in producing hazardous wastes that poses serious threat on the environment. The aim of this study is to synthesize zinc oxide nanoparticles (ZnO NPs) and composite ZnO nanoparticles (CZnO NPs) using cassava leaf extract. Chemical precipitation method was used to synthesize ZnO NPs and CZnO NPs. Both nanoparticle samples were characterized using analytical techniques such as Fourier Transform Infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF) and Thermogravimetric analysis (TGA). The XRD results revealed the 6 mineral phases in cassava leave, 7 mineral phases in composite ZnO NPs and 7 mineral phases in ZnO NPs. SEM morphology revealed large, rough, irregular shaped particle sizes which looks like particle agglomeration. The FTIR results showed the broad band at 3276.33 cm-1, 2046.31 cm-1, 1606.48 cm-1, 1158.2 cm-1, 868.47 cm-1 stretching which indicate O-H, C=O, C-O, and ZnO stretch respectively. The TGA results showed thermal stability of 100 g of ZnO samples up to over 300 oC before decreasing. In conclusion, the ZnO NPs and its composite ZnO NPs were successfully synthesized and exhibited close similar qualities.

Environmental friendly ? – Fe2O3nanoparticles were successfully synthesized via a facile and cost effective chemical precipitation method with the extraction of Nyctanthesarbortristis for the first time. Also it is undergone at room temperature for super capacitor applications and that was observed through electrochemical studies. The prepared samples were characterized by powder X-ray diffraction (XRD), Field emission Scanning electron microscopy (FE-SEM) and UV visible spectroscopic studies. The powder X-ray diffraction study revealed the formation of ? - Fe2O3 in the case of annealed sample. Microscopic images displays that the ? – Fe2O3 nanoparticles were highly agglomerated in nature with the dimension of the order of 2 - 3 ?m. Cyclic voltammetry and simultaneous galvanostatic charge/discharge studies were performed in order to find out the suitability of the material for Supercapacitor applications. The electrochemical results explores that the annealed sample (? – Fe2O3) had improved performance due to its structural with superiority nature. Moreover, the capacitance retention of the ? - Fe2O3 based electrode shows highly stable performance and also its suitability as a lasting electrode material for Super capacitor applications.

Sample pretreatment methods, such as separation / preconcentration prior to the determination of metal ions have developed rapidly due to the increasing need for accurate and precise measurements at extremely low levels of ions in diverse matrices. The development of new sorbents and their application in preconcentration methods for determination of trace analytes is subject of great interest. This review summarizes and discusses several analytical methods involving the preparation and use of new solid phase extractant. A literature survey of the last ten years offering a critical review of these new sorbents available for use in trace analyte enrichment is provided.

In recent time, copper nanoparticles (Cu-NPs) are versatile nanomaterials that find wide array of utilizations in biomedicine, molecular biology, dentistry, dye degradation, catalysis, among others. The aim of this study is to assess the quality of Cu-NPs synthesized from copper tailings and reagent grade copper salt. Chemical reduction method was used to synthesize Cu NPs from copper tailings and reagent grade copper salt using sodium tetrahydroborate (NaBH4) as the reducing agent. The synthesized copper nanoparticles were characterized using different analytical techniques such as: quantitative X-ray Diffraction (XRD), scanning electron microscopy (SEM), X-Fluorescence spectroscopy (XRF), Brunauer-Emmett-Teller (BET), Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric analysis (TGA). The results of XRD identified three major mineral phases tenorite Syn, garnet and quartz in tailing (87.3%, 7.8%, and 4.9%) and reagent grade salt (90%, 6%, and 4%) respectively and confirmed the formation of face-centered cubic (FCC) metallic copper. SEM revealed irregular shape particle morphology with rough surface and particle of 31.3 nm for Cu tailings and 37.6 nm for Reagent Cu nanoparticles. XRF revealed high elemental composition of copper in both synthesized nanoparticles from tailings and reagent salt with 85.15% and 85.98% respectively, BET surface area are 342.11 m2/g and 464.95 m2/g for Cu tailings and reagent salts respectively, and FTIR revealed the specific functional groups O-H, C=O, C-O and Cu-O stretching for both tailings and reagent grade Cu-NPs. However, this type of study has not been reported in an accredited journal. Thermogravimetric analysis (TGA) confirms the thermal stability of these Cu-NPs up to 325 °C. In conclusion, synthesized TCu-NPs and and RCu-NPs were pure, highly crystalline, nano-sized and the quality of the nanoparticles from tailings was slightly lesser than the reagent grade salt due to the presence of impurities. KEYWORDS: Copper tailing, reagent grade copper salt, chemical reduction, copper nanoparticles, characterization

Phase-stabilized Y?O?–ZrO? nanocomposite were successfully synthesized in two different ratios (60% Y2O3-ZrO2 & 40% Y2O3-ZrO2) and systematically characterized to evaluate their potential for photocatalytic degradation applications. X-ray diffraction (XRD) analysis confirmed the formation of a stabilized cubic/tetragonal zirconia phase with fine crystallite size, indicating the effective incorporation of Y?O? into the ZrO? lattice. FTIR spectra revealed the characteristic metal–oxygen vibrational modes associated with Y–O and Zr–O bonding, further supporting the structural stability of the nanomaterials. UV–Visible absorption studies showed a strong absorption edge in the UV region with a reduced band gap, demonstrating enhanced photo-response suitable for photocatalysis. SEM analysis illustrated the formation of uniformly distributed nanosized particles with controlled morphology, which facilitates efficient charge separation during photocatalytic reactions. The photocatalytic studies confirmed that the Y?O?-ZrO? nanocomposite exhibit superior degradation efficiency toward organic pollutants under UV irradiation, attributed to their improved structural stability, optical activity, and surface morphology. These findings highlight the potential of Y?O?–ZrO? nanostructures as promising photocatalysts for environmental remediation applications.

 In this research to estimate of the forming energy of Zn-Ferrite were used of the isothermal reaction by using Avrami equation and Avrami Ozawa for Non-Isothermal reaction in use Flow Injection Synthesis reactor, whether as Isothermal or non-isothermal. According the methods above can be obtainedthe formation energy of Zn-Ferrite. In this research have be done four time isothermal experiments at the temperature 60 0C,70 0C and 80 0C respectively. The sampling of experiment data have be done effectively using pH data logger where both pH and temperature were written in SD card memory automaticallyin form Excel format. As a result the formation enthalpy (?H) 4.2 kcal / mol with entropy (S) 12.6 cal / mol deg and 3:14 density gr / cc,respectively

Smooth and adhesive nanocrystalline diamond (NCD) and microcrystalline diamond (MCD) coatings have been achieved on a chemically etched cemented tungsten carbide (WC-6%Co) substrates, using hot filament chemical vapor deposition (HFCVD) technique. Structural and micro-structural characteristics of these coatings were compared using X-ray diffraction (XRD), Raman spectroscopy and Scanning electron microscopy (SEM) techniques. The parameters affecting the integrity of these coating-substrate systems were studied and mathematical analysis was carried out for calculating the force of de-lamination and load bearing capacity.

This research will examine synthesis of single-wall carbon nanohorns (SWCNHs) by dielectrophoresis (DEP). This will involve electrokinetic synthesis method which will produce a SWCNHs sensor. In dielectrophoresis (DEP), the carbon particles will be subjected to a non-uniform electric field and thus a force will be exerted on the particles. The materials are dielectrically polarized with electrokinetic motion in non-uniform electric fields. The region of higher electric field will attract the nanoparticles due to positive DEP force. The carbon nanoparticles are then trapped in the electrode gap and thus form an electrical connection to the external measuring circuit. This method provides a fast, simple and low cost fabrication of nanomaterial-based sensors based on a bottom-up approach.

Enhancement of photocatalytic activity of titania in the visible region and stabilization of anatase phase are significant from the view point of water pollution abatement, since this will enable solar light mediated processes to be scaled up to meet industrial requirements. Recent research has focused on designing nano titania based catalytic systems due to the large surface areas and improved photogeneration of oxidant-reductant species that the nano particles offer. There are several methods for the synthesis of nanoTiO2. Compared to bare TiO2, metal ion doped TiO2 is advantageous, as the doped metal ion alters the band gap and surface adsorption properties. Iron, zinc, cadmium, lanthanum, cerium, cobalt and nickel ions doped TiO2 have been reported in the literature for photocatalytic application. In this context, the present study aims at the co-doping of nano titania with a transition metal ion and a rare earth metal ion. Copper and Samarium ions have been chosen for this purpose as this co-doping has not been reported in the literature so far. In this paper we have synthesized Cu and Sm ions co-doped nano titania prepared by the sol-gel method. This catalyst was characterized by FTIR, XRD, TGA, SEM and UV- visible to analyze the band gap chatacteristics and the effect of calcination on the photodegradation of 4CP

This paper presents two polyester/vinylester blended nanocomposites in which first, blend filled with nanoclay and the second blend filled with nanoiron particles separately and both were reinforced with aramid fibers. Commercially available nanoclay used as it easily for the composite preparation, whereas nanoiron was synthesized using two compounds Fecl3 6H2o and Fecl24H2o under the presence of ammonium using chemical reduction method. The effects of water immersion on mechanical properties as flexural strength, interlaminar shear strength and impact energy of ironnano and nanoclay filled and unfilled quasi-isotropic aramid fibers reinforced polyester/vinylester blended nanocomposites were investigated. Interlaminar shear strength and flexural strength were obtained with the variation of immersion time (0, 95, 155, 195 and 245 days) and weight percent of filler contents viz. (0, 3, 5, and 6wt. %). Impact energy was measured for dry and wet (after conditioning of 245 days) samples as a function of the variation of filler content. Flexural strength, interlaminar shear strength and impact energy increase with increasing filler content in polymer HFRP (hybrid fiber reinforced Plastics) blended nanocomposites. Immersion in water results in a significant increase of flexural strength, interlaminar shears strength and impact energy, increasing with immersion time. Ironnano particles containing HFRP nanocomposites show higher values of flexural strength, interlaminar shear strength and impact energy than those of nanoclay filled and unfilled HFRP blended nanocomposites as ironnano particle settles around the fibers, thus increasing the toughness.