scholarly journals Dispersion of Titanium Oxide Nanoparticles in Aqueous Solution with Anionic Stabilizer via Ultrasonic Wave

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Wen-Bin Tsai ◽  
Jui-Yang Kao ◽  
Tzong-Ming Wu ◽  
Wen-Tung Cheng
Keyword(s):  
Zeta Potential ◽  
Ph Value ◽  
Average Particle Size ◽  
Oxide Nanoparticles ◽  
Average Particle ◽  
Electrostatic Repulsion ◽  
Titanium Oxide Nanoparticles ◽  
Transmission Electron ◽  
Electronegativity Effect ◽  
Surface Contact Angle

This paper aims to reveal the effects of odium hexametaphosphate (SHMP) and polyacrylic acid (PAA) on dispersion of TiO2 (P25) nanopowder in de-ionic water through ultrasonic horn. We characterized TiO2 suspension by transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), zeta potential, and surface contact angle instruments. As shown in the results, particularly, it were noticed that (1) the SHMP has better dispersion than PAA due to electronegativity effect, resulting in that the average particle size of the dispersed titanium dioxide in de-ionic water was roughly 92 nm, and (2) the zeta potential of TiO2 suspension with SHMP can be achieved by 54 mV at pH value of 7.7, causing stronger electrostatic repulsion in the suspension solution, compared with PAA.

scholarly journals Rapid Synthesis of Gold Nanoparticles with Ginger Waste using Microwave Irradiation

2019 ◽  
Vol 32 (2) ◽  
pp. 471-476
Author(s):  
G. Bhagavanth Reddy ◽  
B. Rajkumar ◽  
K. Girija Mangatayaru ◽  
T.V.D. Prasad Rao
Keyword(s):  
Gold Nanoparticles ◽  
Zeta Potential ◽  
Microwave Irradiation ◽  
Pathogenic Bacteria ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray ◽  
Transmission Electron ◽  
Uv Visible ◽  
The Stability

In the present investigation, synthesis of gold nanoparticles (AuNPs) was carried out with microwave irradiation of HAuCl4 and the extract of ginger waste. Synthesized AuNPs were characterized by various techniques including UV-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), dynamic light scattering (DLS) and transmission electron microscopy (TEM). The TEM images revealed that the nanoparticles were spherical in shape and the average particle size of the AuNPs was found to be approximately 6 ± 2 nm. The stability of gold nanoparticles was analyzed by zeta potential measurements. A negative zeta potential value of -18.4 mV indicates the stability of the AuNPs. Further, gold nanoparticles exhibited the excellent catalytic activity in reducing 4-nitrophenol to 4-aminophenol in the presence of NaBH4 (reducing agent), and it was found to depend on the amount of AuNPs and temperature. Gold nanoparticles did not show any significant antibacterial activity against the pathogenic bacteria studied.

scholarly journals Homogeneous Precipitation Synthesis and Magnetic Properties of Cobalt Ferrite Nanoparticles

2008 ◽  
Vol 2008 ◽  
pp. 1-4 ◽  
Author(s):  
Zhigang Liu ◽  
Xiaodong Li ◽  
Yonghua Leng ◽  
Jingbao Lian ◽  
Shaohong Liu ◽  
...  
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Cobalt Ferrite ◽  
Ph Value ◽  
Average Particle Size ◽  
Spherical Shape ◽  
Average Particle ◽  
Homogeneous Precipitation ◽  
Transmission Electron ◽  
Reaction Solution

Magnetic nanoparticles (NPs) of cobalt ferrite have been synthesized via a homogeneous precipitation route using hexamethylenetetramine (HMT) as the precipitant. The particle size, crystal structure, and magnetic properties of the synthesized particles were investigated by X-ray diffraction, transmission electron microscopy, and vibrating sample magnetometer. The NPs are of cubic inverse spinel structure and nearly spherical shape. With the increase of oxidation time from 30 to 180 minutes in the reaction solution at90∘C, the average particle size increases from ~30 nm to ~45 nm. The as-synthesized NPs ~30 nm in size show higherMs(61.5 emu/g) and moderate Hc (945 Oe) andMr/Ms(0.45) value compared with the materials synthesized by coprecipitation method using NaOH as precipitate at high pH value.

Microstructure Characterization of Ag Nanoparticles Prepared by Hydrothermal Method

2012 ◽  
Vol 476-478 ◽  
pp. 1138-1141
Author(s):  
Zhi Qiang Wei ◽  
Qiang Wei ◽  
Li Gang Liu ◽  
Hua Yang ◽  
Xiao Juan Wu
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Hydrothermal Method ◽  
Ag Nanoparticles ◽  
Average Particle Size ◽  
Average Particle ◽  
Face Centered Cubic ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Face Centered

Ag nanoparticles were successfully synthesized by hydrothermal method under the polyol system combined with traces of sodium chloride, Silver nitrate(AgNO3) and polyvinylpyrrolidone (PVP) acted as the silver source and dispersant respectively. The samples by this process were characterized via X-ray powder diffraction (XRD), Brunauer–Emmett–Teller (BET) adsorption equation, transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED) to determine the chemical composition, particle size, crystal structure and morphology. The experiment results indicate that the crystal structure of the samples is face centered cubic (FCC) structure as same as the bulk materials, The specific surface area is 24 m2/g, the particle size distribution ranging from10 to 50 nm, with an average particle size about 26 nm obtained by TEM and confirmed by XRD and BET results.

Synthesis and Characterization of Water-Soluble Monolayer-Protected Gold Nanoparticles

2011 ◽  
Vol 415-417 ◽  
pp. 617-620 ◽  
Author(s):  
Yan Su ◽  
Ying Yun Lin ◽  
Yu Li Fu ◽  
Fan Qian ◽  
Xiu Pei Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Gold Nanoparticles ◽  
Average Particle Size ◽  
Water Soluble ◽  
Synthesis And Characterization ◽  
Average Particle ◽  
Transmission Electron

Water-soluble gold nanoparticles (AuNPs) were prepared using 2-mercapto-4-methyl-5- thiazoleacetic acid (MMTA) as a stabilizing agent and sodium borohydride (NaBH4) as a reducing agent. The AuNPs product was analyzed by transmission electron microscopy (TEM), UV-vis absorption spectroscopy and Fourier transform infrared spectroscopy (FTIR). The TEM image shows that the particles were well-dispersed and their average particle size is about 5 nm. The UV-vis absorption and FTIR spectra confirm that the MMTA-AuNPs was stabilized by the carboxylate ions present on the surface of the AuNPs.

Study on the synthesis of antibacterial plastic by using silver nanoparticles doped in zeolite framework

2021 ◽  
Vol 6 (1) ◽  
pp. 32-36
Author(s):  
Anh Quoc Le ◽  
Van Phu Dang ◽  
Ngoc Duy Nguyen ◽  
Kim Lan Nguyen Thi ◽  
Kim Lang Vo Thi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Average Particle Size ◽  
Bactericidal Effect ◽  
Ethanol Solution ◽  
Average Particle ◽  
Γ Irradiation ◽  
Zeolite Framework ◽  
Ion Exchange Reaction ◽  
Transmission Electron

Silver nanoparticles (AgNPs) doped in the zeolite framework (AgNPs/Z) were successfully synthesized by γ-irradiation in ethanol solution of silver ion-zeolite (Ag+/Z) prepared by ion exchange reaction between silver nitrate (AgNO3) and zeolite 4A. The effects of the Ag+ concentration and irradiation dose on the formation of AgNPs/Z were also investigated. AgNPs/Z with the silver content of about 10,000 ppm and the average particle size of AgNPs of about 27 nm was characterized by ultraviolet-visible spectroscopy, powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM). Firstly, AgNPs/Z was added into PP resins for creation of PP-AgNPs/Z masterbatch (Ag content of ~10.000 ppm) and then PP-AgNPs/Z plastics were preapared by mixing masterbatch with PP resins. The antibacterial activity of the PP-AgNPs/Z plastics was investigated against Gram-negative bacteria Escherichia coli (E. coli). The results showed that PP-AgNPs/Z plastic contained 100 ppm of Ag possessed a high antibacterial property, namely the bactericidal effect was more than 96 % on the platic surface. In conclusion, possessing many advantages such as: vigorously antibacterial effect and good dispersion in plastic matrix, AgNPs/Z is promising to be applied as bactericidal agent for plastic industry.

Preparation and Electrochemical Properties of Amorphous Tin-Copper Composite Oxide CuSnO3

2012 ◽  
Vol 535-537 ◽  
pp. 31-35
Author(s):  
Tao Liu ◽  
Rong Bin Du ◽  
Xue Jun Kong
Keyword(s):  
Electrochemical Properties ◽  
Lithium Ion Batteries ◽  
Anode Materials ◽  
Average Particle Size ◽  
Lithium Ion ◽  
Average Particle ◽  
Charge Capacity ◽  
Composite Oxides ◽  
Transmission Electron ◽  
Copper Composite

Composite oxides materials CuSnO3as anode materials for lithium-ion batteries were synthesized by chemical coprecipitation method using SnCl4•5H2O, NH3•H2O and Cu(NO3)2•3H2O as raw materials.The precursor CuSn(OH)6and CuSnO3powders were characterized by thermogravimertric(TG) analysis and differential thermal analysis(DTA), X-ray diffraction(XRD), and transmission electron microscope (TEM). The electrochemical properties of CuSnO3powders as anode materials of lithium ion batteries were investigated comparatively by galvanostatic charge-discharge experiments. The results show the average particle size of amorphous CuSnO3is 70nm. The initial capacity during the first lithium insertion is 1078 mA•h/g and the reversible charge capacity in first cycle is 775 mA•h/g. After 20 cycles, the charge capacity is 640 mA•h/g and this material shows moderate capacity fading with cycling. As a novel anode material for lithium ion batteries, amorphous CuSnO3demonstrates a large capacity and a low insertion potential with respect to Li metal.

scholarly journals A Novel Self-Assembled Epitope Peptide Nanoemulsion Vaccine with Targeting the Nasal Mucosal Epithelial Cell for Reinvigorating CD8+ T cell Immune Activity and Inhibiting Tumor Progression

2020 ◽  
Author(s):  
Hongwu Sun ◽  
Yun Yang ◽  
Shuang Ge ◽  
Zhen Song ◽  
Anni Zhao ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Tumor Vaccine ◽  
Average Particle Size ◽  
Physicochemical Characteristics ◽  
Nasal Administration ◽  
Average Particle ◽  
Epitope Peptide ◽  
Antigen Uptake ◽  
Spherical Surfaces ◽  
Th1 Cytokines

Abstract Synthetic epitope peptide are not suitable for nasal administration due to its weak immunogenic and low delivery efficiency. In this work, we developed a intranasal epitope nanovaccine (I-OVA NE) which can prolong mucosal retention and enhance CTL activity induced by epitopes. I-OVA NE was a nanoemulsion system that assembled with IKVAV-OVA257-264(I-OVA) conjugated peptides.This nanovaccine with I-OVA at a concentration of 4 mg/mL showed the average particle size of 30.37±2.49 nm, zeta potential of -16.67±1.76 mV, and encapsulation rate of 84.07±7.59%. I-OVA NE particles exhibit smooth and spherical surfaces, good dispersibility and no obvious aggregation. Moreover, the physicochemical characteristics (size, PdI and zeta potential) of this vaccine did not significantly change in the condition of mucin exist. I-OVA NE had no significant cytotoxic effects on BEAS-2B cells, and no obvious acute pathological changes were observed on nasal mucosa or lung tissue in the mice after nasal immunization. We found that I-OVA NE prolonged the nasal residence time, promoted the cellular uptake of the epitope peptide and improved the antigen uptake efficiency of BEAS-2B cells, but this effect was significantly decreased after integrin blockade. Importantly, the level of Th1 cytokines and the proportion of epitope-specific CD8+ T cells increased significantly, and thus I-OVA NE protected E.G7/OVA tumor-bearing mice by suppressing tumour growth and provoking anti-tumour immune activation. Overall, these data indicate that I-OVA NE can be an applicable strategy for tumor vaccine design.

Preparation and Antibacterial Performances of Electrocatalytic Zinc Oxide Nanoparticles with Diverse Morphologies

2021 ◽  
Vol 17 (9) ◽  
pp. 1824-1829
Author(s):  
Junlin Li ◽  
Xiangfei Li ◽  
Dong Liang ◽  
Xiaojuan Zhang ◽  
Qing Lin ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Surface Area ◽  
Zinc Oxide Nanoparticles ◽  
Average Particle Size ◽  
Three Dimensional ◽  
Diffusion Method ◽  
Oxide Nanoparticles ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Zno Nps

This study exploits the potential of zinc oxide nanoparticles (ZnO-NPs) with diverse morphologies as catalysts and antibacterial agent. Spherical ZnO-NPs, rod-shaped ZnO-NPs and flower-shaped ZnO-NPs were prepared by microemulsion method, solvent heat method and hydrothermal method, respectively. The structural characterizations of samples were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. XRD results revealed the formation of spherical ZnO-NPs, rod-shaped ZnO-NPs and flower-shaped ZnO-NPs were all wurtzite crystal structure. SEM results showed that spherical ZnO-NPs had an average particle size of 30–40 nm, rod-shaped ZnO-NPs were about 500 nm long and 100 nm wide with obvious hexagonal crystals. Flower-shaped ZnO-NPs had a three-dimensional appearance with obvious petals. Results of electrochemical HER (Hydrogen evolution reaction) experiments revealed that spherical ZnO-NPs exhibited the highest electrocatalytic activity at the lowest potential voltage due to their largest specific surface area. The antibacterial property of ZnO-NPs samples were studied by the optical density method and disc diffusion method. All samples had antibacterial effects against E. coli. and flower-shaped ZnO-NPs showed the best antibacterial activity due to the largest surface area in comparison with spherical ZnO-NPs and rod-shaped ZnO-NPs, which promised the maximum Zn2+ release as bactericide mechanism that registered in the case of different ZnO-NPs morphologies.

Catalytic Reduction of Nitrobenzene Using Silver Nanoparticles Embedded Calcium Alginate Film

2019 ◽  
Vol 19 (11) ◽  
pp. 7487-7492 ◽  
Author(s):  
Supriya ◽  
Jayanta Kumar Basu ◽  
Sonali Sengupta
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Sodium Borohydride ◽  
Calcium Alginate ◽  
Catalytic Reduction ◽  
Average Particle Size ◽  
Catalyst Loading ◽  
Average Particle ◽  
Transmission Electron

Synthesis of silver nanoparticles embedded on calcium alginate film and the catalytic property of this film in the reduction of nitrobenzene with sodium borohydride are demonstrated in this work. Natural polymer alginate acts as effective reducing and stabilizing agent in synthesis of silver nanoparticles. Effect of different parameters on the preparation of silver nanoparticles, such as, temperature, concentration of silver precursor and heating time was investigated. As-prepared silver nanoparticles were characterized by transmission electron microscopy, scanning electron microscopy, UV-Vis spectrometry, and atomic absorption spectrometry. Transmission electron microscopy analysis con-firms the formation of silver nanoparticles with particles size range of 3–19 nm and average particle size was found to be 10±4 nm. Effect of concentration of nitrobenzene and sodium borohydride, catalyst loading and temperature on the catalytic reduction of nitrobenzene was studied. Reusability of catalyst was examined in this reduction reaction and the catalyst shows good activity up to 10th run.

scholarly journals Green Synthesis of Novel Jasmine Bud-Shaped Copper Nanoparticles

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Malathi Sampath ◽  
Ramya Vijayan ◽  
Ezhilarasu Tamilarasu ◽  
Abiraman Tamilselvan ◽  
Balasubramanian Sengottuvelan
Keyword(s):  
Copper Nanoparticles ◽  
Isonicotinic Acid ◽  
Chemical Reduction ◽  
Average Particle Size ◽  
Acid Hydrazide ◽  
Reducing Agent ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Atomic Force ◽  
Transmission Electron

Novel jasmine bud-shaped copper nanoparticles were synthesized by a green chemical reduction method using polyvinylpyrrolidone (PVP) as a capping agent, L-ascorbic acid (AA) as a reducing agent as well as antioxidant agent, isonicotinic acid hydrazide (INH) as a reducing agent, and water as a solvent at 60–70°C (pH-7) in the presence of air. The UV-Vis absorption maximum obtained is 573 nm. The crystal lattice (fcc) structure of Cu Nps was confirmed by X-ray diffraction (XRD). The novel jasmine bud shape was visualized in a transmission electron microscope (TEM). The height of single copper nanobud was 6.41 nm as measured by atomic force microscope (AFM). The average particle size 6.95 nm is obtained by XRD results. Antibacterial activity of the Cu nanobuds was evaluated by testing against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria.

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