scholarly journals A Study On Dispersion Stability Of Nickel Nanoparticles Synthesized By Wire Explosion In Liquid Media

2015 ◽  
Vol 60 (2) ◽  
pp. 1379-1382 ◽  
Author(s):  
C.K. Kim ◽  
G.-J. Lee ◽  
M.K. Lee ◽  
C.K. Rhee
Keyword(s):  
Nickel Nanoparticles ◽  
Spherical Shape ◽  
Physical Method ◽  
Average Diameter ◽  
Dispersion Stability ◽  
Wire Explosion ◽  
Transmission Electron ◽  
One Step ◽  
Polymer Surfactant ◽  
Microscopy Images

Abstract In this study, nickel nanoparticles were synthesized in ethanol using portable pulsed wire evaporation, which is a one-step physical method. From transmission electron microscopy images, it was found that the Ni nanoparticles exhibited a spherical shape with an average diameter of 7.3 nm. To prevent aggregation of the nickel nanoparticles, a polymer surfactant was added into the ethanol before the synthesis of nickel nanoparticles, and adsorbed on the freshly synthesized nickel nanoparticles during the wire explosion. The dispersion stability of the prepared nickel nanofluids was investigated by zeta-potential analyzer and Turbiscan optical analyzer. As a result, the optimum concentration of polymer surfactant to be added was suggested for the maximized dispersion stability of the nickel nanofluids.

Gold Nanoparticles Supported on SrTiO3 by Solution Plasma Sputter Deposition for Enhancing UV- and Visible-light Photocatalytic Efficiency

2013 ◽  
Vol 1509 ◽  
Author(s):  
Gasidit Panomsuwan ◽  
Nobuyuki Zettsu ◽  
Nagahiro Saito
Keyword(s):  
Visible Light ◽  
Au Nanoparticles ◽  
Spherical Shape ◽  
Average Diameter ◽  
Sputter Deposition ◽  
Transmission Electron ◽  
One Step ◽  
Blue Solution ◽  
Photocatalytic Applications ◽  
Visible Light Photocatalytic

ABSTRACTGold (Au) nanoparticles were synthesized and deposited on the perovskite SrTiO3 (STO) via a one-step solution plasma sputter deposition (SPSD) without any reducing reagents at ambient condition. Good dispersion of the Au nanoparticles deposited on the STO surface was clearly observed. The synthesized Au nanoparticles were well-crystallized with a spherical shape and preferably exhibited multiply twinned structure. An average diameter of Au nanoparicles was estimated to be 6.1 ± 1.4 nm by transmission electron microscopy. Enhanced photocatalytic activity was found for the Au-STO when compared to the pure STO, as investigated from the degradation of methylene blue solution under ultraviolet and visible light irradiation. The SPSD seems to be a rapid and facile approach to prepare the Au nanoparticles supported on the metal oxide for photocatalytic applications.

Antifungal Effectiveness of Nanosilver Colloid against Rose Powdery Mildew in Greenhouses

2008 ◽  
Vol 135 ◽  
pp. 15-18 ◽  
Author(s):  
Hae Sic Kim ◽  
Hyun Suk Kang ◽  
Gyo Jin Chu ◽  
Hong Sik Byun
Keyword(s):  
Electron Microscopy ◽  
Powdery Mildew ◽  
Colloidal Solution ◽  
Physical Method ◽  
Average Diameter ◽  
Optical Microscope ◽  
Size Analysis ◽  
Large Area ◽  
Transmission Electron ◽  
Antifungal Effects

The antifungal effectiveness against rose powdery mildew using antimicrobial nanosilver colloidal solution was investigated. Double-capsulized nanosilver was prepared by chemical reaction of silver ion with aid of physical method, reducing agent and stabilizers. The average diameter of nanosilver was about 1.5 nm. They were highly stable and very well dispersive in aqueous solution. The Transmission electron microscopy and UV-vis spectrometer were used for measurements of size analysis and their stability, respectively. The nanosilver colloidal solution of concentration of 5000 ppm was diluted in 10 ppm of 500 kg and sprayed at large area of 3306 m2polluted by rose powdery mildew. The white rose powdery mildew fade out above 95 % after 2 days and was not recurred for a week. The antifungal effects were observed by an optical microscope and photographs.

scholarly journals A novel nano zero-valent iron@chitosan for effective removal of Microcystin-LR: Kinetics and adsorption mechanism

2018 ◽  
Vol 53 ◽  
pp. 04004 ◽  
Author(s):  
Xiaofan Yang ◽  
Xueyu Wei ◽  
Xiaoping Xu ◽  
Zhigang Liu
Keyword(s):  
Low Cost ◽  
Spherical Shape ◽  
Step Method ◽  
Variable Parameters ◽  
Transmission Electron ◽  
Effective Removal ◽  
Initial Ph ◽  
Nano Zero Valent Iron ◽  
One Step ◽  
Kinetics Of

Microcystin-LR (MC-LR) is one of the most notorious toxins liberated from cyanobacteria in drinking water sources. In this study, a skillful method access to new nanozero-valent iron @chitosan (nZVIMC) was synthesized by a facile one step method. The as-prepared nZVIMC was employed as an adsorbent for the effective removal MC-LR from aqueous solution. Transmission electron microscopy (TEM) demonstrates that nZVIMC is in quasi-spherical shape with size of around 50 nm, effect of variable parameters such as pH, contact time, initial concentration of MC-LR and adsorption properties of nZVIMC on MC-LR was further investigated. Scanning electron microscope (SEM) reveals that the particles are nearly spherical in shape with agglomeration. The results indicated that good adsorption performance was achieved at an initial pH of 5. The adsorption kinetics of nZVIMC was better fitted by pseudo-secondorder kinetics. The adsorption isotherm data was fitted well to Langmuir isotherm and then to Freundlich model, with an adsorption capacity of 68.9 mg/g at 300K. Thus, we believe that nZVIMC can be used as a low cost material for efficient removal of MC-LR from water.

Fabrication and Electrical Characterization of Metal-Silicide Nanocrystals for Nano Floating Gate Nonvolatile Memory

2009 ◽  
Vol 1160 ◽  
Author(s):  
Seung Jong Han ◽  
Ki Bong Seo ◽  
Dong Uk Lee ◽  
Eun Kyu Kim ◽  
Se-Mam Oh ◽  
...  
Keyword(s):  
Nonvolatile Memory ◽  
Electrical Characterization ◽  
Spherical Shape ◽  
Average Diameter ◽  
Floating Gate ◽  
Flat Band ◽  
Hysteresis Curve ◽  
Flat Band Voltage ◽  
Transmission Electron ◽  
Floating Gate Memory

AbstractWe have fabricated the nano-floating gate memory with the TiSi2 and WSi2 nanocrystals embedded in the dielectrics. The TiSi2 and WSi2 nanocrystals were created by using sputtering and rapidly thermal annealing system, and then their morphologies were investigated by transmission electron microscopy. These nanocrystals have a spherical shape with an average diameter of 2-5 nm. The electrical properties of the nano-floating gate memory with TiSi2 and WSi2 nanocrystals were characterized by capacitance-voltage (C-V) hysteresis curve, memory speed and retention. The flat-band voltage shifts of the TiSi2 and WSi2 nanocrystals capacitors obtained appeared up to 4.23 V and 4.37 V, respectively. Their flat-band voltage shifts were maintained up to 1.6 V and 1 V after 1 hr.

scholarly journals BIODEGRADABLE GELATIN DECORATED Fe3O4 NANOPARTICLES FOR PACLITAXEL DELIVERY

2018 ◽  
Vol 55 (1B) ◽  
pp. 7 ◽  
Author(s):  
Dai Hai Nguyen
Keyword(s):  
Fe3o4 Nanoparticles ◽  
Drug Loading ◽  
Spherical Shape ◽  
Average Diameter ◽  
Precipitation Method ◽  
Loop Analysis ◽  
Transmission Electron ◽  
Potential Applications ◽  
Size And Morphology ◽  
Co Precipitation

The objective of this study is to prepare biodegradable iron oxide nanoparticles with gelatin (GEL) for paclitaxel (PTX) delivery. In detail, Fe3O4 nanoparticles were prepared and then coated them with GEL (Fe3O4@GEL) conjugate by co–precipitation method. Furthermore, the formation of Fe3O4@GEL was demonstrated by Fourier transform infrared (FT–IR) and powder X–ray diffraction (XRD). The superparamagnetic property of Fe3O4@GEL was also showed by hysteresis loop analysis, the saturation magnetization reached 20.36 emu.g–1. In addition, size and morphology of Fe3O4@GEL nanoparticles were determined by transmission electron microscopy (TEM). The results indicated that Fe3O4@GEL nanoparticles were spherical shape with average diameter of 10 nm. Especially, PTX was effectively loaded into the coated magnetic nanoparticles, 86.7 ± 3.2 % for drug loading efficiency and slowly released up to 5 days. These results suggest that the potential applications of Fe3O4@GEL nanoparticles in the development of stable drug delivery systems for cancer therapy.

PREPARATION AND CHARACTERIZATION OF AMINO-MODIFIED Fe3O4 MAGNETIC NANOCOMPOSITE PARTICLES BY ONE-STEP GLYCOTHERMAL METHOD

2013 ◽  
Vol 27 (19) ◽  
pp. 1341002 ◽  
Author(s):  
YUHONG ZHANG ◽  
BIAO YAN ◽  
TAIGANG SHI
Keyword(s):  
Iron Oxide ◽  
Average Diameter ◽  
Magnetic Nanocomposite ◽  
Spherical Particles ◽  
X Ray Diffraction ◽  
Nanocomposite Particles ◽  
Glycothermal Method ◽  
Transmission Electron ◽  
One Step

Amino-modified Fe 3 O 4 magnetic nanocomposite particles were prepared by one-step glycothermal method. The shape and morphology of Fe 3 O 4 particles change when a small amount of water is added as a co-solvent in the glycothermal method. The morphology and structure of the sample were characterized and measured by transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. TEM images show that the morphology of the samples is from irregular polyhedron to spherical particles. Average diameter of particles is approximately 70/40/10 nm and more evenly distributed. XRD results show that the samples are cubic spinel structure. FTIR results show that a chemical bonds combination exists between the amino and iron oxide, nano-iron oxide are modified by the amino.

scholarly journals Nanocrystallization of Anthocyanin Extract from Red-Fleshed Apple ′QN-5′ Improved Its Antioxidant Effect through Enhanced Stability and Activity under Stressful Conditions

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1421 ◽  
Author(s):  
Xiang Zhang ◽  
Heqiang Huo ◽  
Xiaohong Sun ◽  
Jun Zhu ◽  
Hongyi Dai ◽  
...  
Keyword(s):  
Storage Time ◽  
Spherical Shape ◽  
Average Diameter ◽  
Anthocyanin Content ◽  
Capacity Loss ◽  
Transmission Electron ◽  
Scavenging Capacity ◽  
Alkaline Conditions ◽  
Regular Spherical Shape ◽  
Scavenging Rates

Red-flesh apples are known as functional fruits because of their rich anthocyanin. The anthocyanin content of the red flesh apple cultivar ′QN-5′ we bred can reach 361 mg·kg−1 (FW), and showed higher scavenging capacity to DPPH radicals, hydroxyl radicals, and superoxide anion radicals, with scavenging rates of 80.0%, 54.0%, and 43.3%, respectively. We used this particular anthocyanin-rich ′QN-5′ apple as material to examine how nanocrystallization affects the antixodiant effect of anthocyanin. The anthocyanin extract was encapsulated with biocompatible zein to form zein-anthocyanin nanoparticles (ZANPs). Transmission electron microscopy (TEM) scanning showed that ZANPs had a regular spherical shape with an average diameter size of 50–60nm. When the ratio of the zein and the anthocyanin was 1:0.5, the results suggested that the encapsulation efficiency (EE) of the ZANPs could reach as high as 92.8%, and that scavenging rate for DPPH radicals was increased from 87.1% to 97.2% compared to the non-nanocrystallized anthocyanin extract. Interestingly, treatment under alkaline conditions (pH 9.0), high temperature (90 °C), and a storage time of 7 days could decrease the scavenging capacity of the ZANPs for DPPH radicals, but this scavenging capacity loss for ZANPs was significantly lower than that observed in the non-nanocrystallized anthocyanin, suggesting the higher stability of ZANPs is caused by encapsulation. These results would provide a theoretical basis for the application of the anthocyanin in scavenging free radicals under stress conditions.

Controlled Growth of ZnO Nanocrystals on the Surface of SiO2 Spheres

2009 ◽  
Vol 151 ◽  
pp. 264-268 ◽  
Author(s):  
Yuliya V. Yermolayeva ◽  
Yuriy N. Savin ◽  
Alexander V. Tolmachev
Keyword(s):  
Average Diameter ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zno Nanocrystals ◽  
Transmission Electron ◽  
Zno Particles ◽  
One Step ◽  
Shell Particles ◽  
Sio2 Spheres

The “islands” of ZnO nanocrystals on amorphous monodisperse 200 nm SiO2 spheres (core-shell particles) were obtained by simple one-step technique based on low-temperature crystallization from liquid phase. The influence of starting reagents types and concentration of zinc ions in the reaction mixture on the morphology of ZnO shells obtained was studied. Crystalline structure of ZnO nanocrystals obtained was proofed by the X-ray diffraction data. The average diameter of ZnO nanocrystals on SiO2 spheres is 10 nm according to X-ray diffraction (XRD) and transmission electron microscopy (TEM) data. It was shown that SiO2/ZnO particles obtained have high luminescence characteristics. Photoluminescence spectra of core-shell SiO2/ZnO particles show two emission peaks centred at 386 nm and 570 nm. Core-shell SiO2/ZnO particles obtained are perspective for active photonic crystals creation for UV-spectral region.

Evaluation of the Dispersion Stability of Nanocarbons Using Zeta Potential in Distilled Water

2019 ◽  
Vol 26 ◽  
pp. 8-19
Author(s):  
Jamal M.A. Alsharef ◽  
Mohd Raihan Taha ◽  
Ramez A. Al-Mansob ◽  
Panbarasi Govindasamy
Keyword(s):  
Electron Microscopy ◽  
Zeta Potential ◽  
Carbon Nanofiber ◽  
Physical Method ◽  
Potential Method ◽  
Dispersion Stability ◽  
Chemical Agent ◽  
Distilled Water ◽  
Ultrasonic Dispersion ◽  
Transmission Electron

Nanocarbons (NCs) have exceptional mechanical, electrical, and thermal properties as compared to conventional carbon fibers. In previous studies, chemical agent has been used to disperse NCs in the colloid. The main objective of this study is to investigate the dispersion stability of NCs in distilled water and measurement the Zeta Potential value after using ultrasonic dispersion method (physics method). Two types of NCs were used in this study, carbon nanotube (CNT), and Carbon nanofiber (CNF) with different amounts and sonication time of 2 to 12 minutes. The field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) is utilised to inspect the efficiency of the dispersion methodology. The result has shown the significate dispersion of NCs. It was found that the Zeta Potential was 57.5 mV, and 50.9 mV for CNT, and CNF respectively after one month of sonication process. Moreover, the result indicates that the solution is in good stability according to ASTM standard D418-82. Thus, this physical method used in this study can be further considered as a potential method for NCs dispersion when mixed with a different application. Keywords: Nanocarbons, Dispersion, Zeta Potential, Sonication, Nanomaterials

scholarly journals Carbon supported manganese(IV)–cobalt(II/III) oxides nanoparticles for high-performance electrochemical supercapacitors

Chemija ◽  
2020 ◽  
Vol 31 (2) ◽  
Author(s):  
Jolita Jablonskienė ◽  
Dijana Šimkūnaitė ◽  
Jūratė Vaičiūnienė ◽  
Giedrius Stalnionis ◽  
Audrius Drabavičius ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
High Performance ◽  
Optical Emission ◽  
Spherical Shape ◽  
High Specific Capacitance ◽  
Inductively Coupled ◽  
Transmission Electron ◽  
One Step ◽  
Shape Of Nanoparticles

The carbon supported manganese(IV)–cobalt (II/III) oxides nanoparticles labelled as MnO2–Co3O4/C nanocomposites have been prepared by a simple one-step microwave-assisted heating method using different precursor materials. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and inductively coupled plasma optical emission spectroscopy (ICP-OES) have been used for the characterization of morphology, structure and composition of the synthesized nanocomposites, whereas the electrochemical performance of the prepared nanocomposites has been evaluated by using cyclic voltammetry (CV). It was determined that the use of different precursor materials for the synthesis of the carbon supported MnO2 and Co3O4 nanocomposites results in a different morphology of the prepared substances. A high specific capacitance (Cs) of 658.8 F g−1 at a scan rate of 10 mV s−1 in a 1 M Na2SO4 solution has been obtained for the MnO2–Co3O4/C-2 nanocomposite that has a spherical shape of nanoparticles. Moreover, it significantly outperforms the MnO2–Co3O4/C-1 nanocomposite that has a lamellar shape of nanoparticles.

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