scholarly journals Facile Synthesis of Carboxymethyl Cellulose Coated Core/Shell SiO2@Cu Nanoparticles and Their Antifungal Activity against Phytophthora capsici

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 888
Author(s):  
Nguyen Thi Thanh Hai ◽  
Nguyen Duc Cuong ◽  
Nguyen Tran Quyen ◽  
Nguyen Quoc Hien ◽  
Tran Thi Dieu Hien ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Carboxymethyl Cellulose ◽  
Chemical Reduction ◽  
Low Cost ◽  
Phytophthora Capsici ◽  
Reduction Process ◽  
Spherical Shape ◽  
Core Shell ◽  
Cu Nanoparticles ◽  
Average Size

Cu nanoparticles are a potential material for creating novel alternative antimicrobial products due to their unique antibacterial/antifungal properties, stability, dispersion, low cost and abundance as well as being economical and ecofriendly. In this work, carboxymethyl cellulose coated core/shell SiO2@Cu nanoparticles (NPs) were synthesized by a simple and effective chemical reduction process. The initial SiO2 NPs, which were prepared from rice husk ash, were coated by a copper ultrathin film using hydrazine and carboxymethyl cellulose (CMC) as reducing agent and stable agent, respectively. The core/shell SiO2@Cu nanoparticles with an average size of ~19 nm were surrounded by CMC. The results indicated that the SiO2@Cu@CMC suspension was a homogenous morphology with a spherical shape, regular dispersion and good stability. Furthermore, the multicomponent SiO2@Cu@CMC NPs showed good antifungal activity against Phytophthora capsici (P. capsici). The novel Cu NPs-based multicomponent suspension is a key compound in the development of new fungicides for the control of the Phytophthora disease.

Antimicrobial and Cytotoxic Activity of Silver Nanoparticles Stabilized by Natural Biopolymer Arabinogalactan

2020 ◽  
Vol 19 (04) ◽  
pp. 1950029
Author(s):  
A. G. Demchenko ◽  
V. S. Sadykova ◽  
A. V. Lyundup ◽  
N. E. Sedyakina ◽  
T. I. Gromovykh ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antifungal Activity ◽  
Cytotoxic Activity ◽  
Chemical Reduction ◽  
Antitumor Agent ◽  
Escherichia Coli Bacteria ◽  
Trichoderma Citrinoviride ◽  
Average Size ◽  
Antibacterial And Antifungal ◽  
Dose Dependent

Silver nanoparticles were synthesized by chemical reduction of silver nitrate using arabinogalactan polysaccharide as a reducing agent and a stabilizer. The average size of nanoparticles, obtained by analyzing TEM-images, was 10.8[Formula: see text]nm; zeta potential [Formula: see text][Formula: see text]mV. A study of the sol by electron diffraction showed that silver in the sample is in metallic form. The resulting preparation of silver nanoparticles showed both antibacterial and antifungal activity. A pronounced antibacterial activity of silver nanoparticles was demonstrated both in relation to conditionally pathogenic gram-positive (Bacillus subtilis and B. coagulans) and gram-negative (Escherichia coli) bacteria. Silver nanoparticles also possess antifungal activity against macromycete Fomitopsis sp., as well as two strains of micromycetes Trichoderma citrinoviride and Fusarium sporotrichioides. Using the methods of light and fluorescence microscopy, MTT-analysis and Real-time cell analysis, the cytotoxic activity of silver nanoparticles was investigated on HepG2 human hepatocellular carcinoma cells. It was demonstrated that nanoparticles cause a suppression of cell metabolic and proliferative activity, as well as dose-dependent induction of cell death (average relative EC[Formula: see text] value was [Formula: see text]g/ml). The preparation of silver nanoparticles stabilized by arabinogalactan can be used in medicine, as a potential antimicrobial and antitumor agent.

Synthesis of Fine Nickel Powders by Solvothermal Method

2007 ◽  
Vol 334-335 ◽  
pp. 1145-1148 ◽  
Author(s):  
Yin Ye ◽  
Fang Li Yuan ◽  
Li Min Zhou ◽  
Hai Tao Huang
Keyword(s):  
Thermal Stability ◽  
Chemical Reduction ◽  
Spherical Shape ◽  
Butyl Alcohol ◽  
Nickel Powders ◽  
Good Crystallinity ◽  
Average Size ◽  
Solvothermal Conditions ◽  
Thermal Stability Of ◽  
Fine Nickel

Fine nickel powders have been prepared by chemical reduction between nickel acetate and alcohol under solvothermal conditions. The effect of adding surfactant and varying solvent on the particle size of the as-synthesized nickel powders have been explored. SEM, XRD and TG were employed to characterize the size, morphology, crystalline structure and the thermal stability of the as-synthesized nickel powders. It is revealed that the FCC-structured nickel powders are of uniform spherical shape with good crystallinity and thermal stability. Typically, nickel powders with an average size of 300 nm were obtained at 200°C for 8 h using 0.04 mol/L solution of Ni(CH3COO)2·4H2O in n-butyl alcohol under solvothermal conditions.

Using Response Surface Methodology in Synthesis of Ultrafine Copper Nanoparticles by Electrolysis

2016 ◽  
Vol 15 (01n02) ◽  
pp. 1650001 ◽  
Author(s):  
A. Tamilvanan ◽  
K. Balamurugan ◽  
K. Ponappa ◽  
B. Madhan Kumar
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Process Parameters ◽  
Low Cost ◽  
Cu Nanoparticles ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Electrode Gap ◽  
Average Size ◽  
Ultrafine Copper

Electrolysis is a method used for producing copper (Cu) nanoparticles at faster rate and at low cost in ambient conditions. The property of Cu nanoparticles prepared by electrolysis depends on their process parameters. The influence of selected process parameters such as copper sulfate (CuSo4) concentration, electrode gap and electrode potential difference on particle size was investigated. To optimize these parameters response surface methodology (RSM) was used. Cu nanoparticles prepared by electrolysis were characterized by using X-ray diffraction (XRD) and scanning electron microscope (SEM). After reviewing the results of analysis of variance (ANOVA), mathematical equation was created and optimized parameters for producing Cu nanoparticles were determined. The results confirm that the average size of Cu particle at the optimum condition was found to be 17[Formula: see text]nm and they are hexagonal in shape.

Synthesis and Characterization of SiO2@Y2MoO6:Eu3+ Core–Shell Structured Spherical Phosphors by Sol–Gel Process

2016 ◽  
Vol 16 (4) ◽  
pp. 3914-3920 ◽  
Author(s):  
G. Z Li ◽  
F. H Liu ◽  
Z. S Chu ◽  
D. M Wu ◽  
L. B Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Annealing Temperature ◽  
Uv Light ◽  
Sol Gel ◽  
Spherical Shape ◽  
Core Shell ◽  
X Ray ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Average Size

SiO2@Y2MoO6:Eu3+ core–shell phosphors were prepared by the sol–gel process. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectra (EDS), transmission electron microscopy (TEM), photoluminescence (PL) spectra as well as kinetic decays were used to characterize the resulting SiO2@Y2MoO6:Eu3+ core–shell phosphors. The XRD results demonstrated that the Y2MoO6:Eu3+ layers on the SiO2 spheres crystallized after being annealed at 700 °C and the crystallinity increased with raising the annealing temperature. The obtained core–shell phosphors have spherical shape with narrow size distribution (average size ca. 640 nm), non-agglomeration, and smooth surface. The thickness of the Y2MoO6:Eu3+ shells on the SiO2 cores could be easily tailored by varying the number of deposition cycles (70 nm for four deposition cycles). The Eu3+ shows a strong PL emission (dominated by 5D0–7F2 red emission at 614 nm) under the excitation of 347 nm UV light. The PL intensity of Eu3+ increases with increasing the annealing temperature and the number of coating cycles.

Pure Copper Solder Paste with Sub-200 °C Processing Temperature

2011 ◽  
Vol 2011 (1) ◽  
pp. 001033-001039
Author(s):  
Alfred A. Zinn ◽  
Frances Y. Chiu
Keyword(s):  
Thermal Conductivity ◽  
Chemical Reduction ◽  
Low Cost ◽  
Pure Copper ◽  
Advanced Technology ◽  
Melting Point Depression ◽  
Processing Temperature ◽  
Solder Paste ◽  
Cu Nanoparticles ◽  
Tap Density

At the Advanced Technology Center of Lockheed Martin Corporation, we have developed a copper-based electrical interconnect material that can be processed around 200 °C. The material can be dispensed using Gauge 20–30 syringe tips and has shown electrical and thermal conductivity that progresses toward the bulk copper values. The approach is enabled by our controlled fabrication process of Cu nanoparticles, which takes advantage of rapidly increasing melting point depression as the particle size approaches the nanoscale. The readily scalable synthesis of Cu nanoparticles uses a low cost solution-phase chemical reduction approach. XRD, SEM and HRTEM confirm the formation of stable Cu nanoparticles as small as 10 nm and below and the effectiveness of the surfactant mixture to prevent oxidation. We have demonstrated assembly of fully functional LED test boards and built for the first time a fully functional small camera board using all Cu nanoparticle based pastes with a consistency very similar to standard SAC solder paste and a tap density approaching 6 g/ccm. Initial tensile testing gave values around 50% of eutectic SnPb solder. Once fully optimized, the pure copper electrical interface material is expected to produce joints with up to 10x electrical and thermal conductivity compared to the tin-based materials currently in use.

scholarly journals Bismuth nanoparticles obtained by a facile synthesis method exhibit antimicrobial activity against Staphylococcus aureus and Candida albicans

2020 ◽  
Author(s):  
Roberto Vazquez-Munoz ◽  
M. Josefina Arellano-Jimenez ◽  
Jose Lopez-Ribot
Keyword(s):  
Staphylococcus Aureus ◽  
Candida Albicans ◽  
Antifungal Activity ◽  
Chemical Reduction ◽  
Synthesis Method ◽  
Reduction Process ◽  
Pathogenic Yeast ◽  
Bismuth Nanoparticles ◽  
Growing Conditions ◽  
Opportunistic Pathogenic

AbstractBismuth compounds are known for their activity against multiple microorganisms; yet, the antibiotic properties of bismuth nanoparticles (BiNPs) remain poorly explored. The objective of this work is to further the research of BiNPs for nanomedicine, particularly as a disinfectant and for future treatments. Stable PVP-coated BiNPs were produced by a chemical reduction process, in less than 30 minutes, in a heated alkaline glycine solution, by the chelation and reduction of the bismuth (III) ion; resulting in the generation of small, spheroid particles with a crystalline organization. We assessed the antibacterial and antifungal activity of bismuth nanoparticles. PVP-BiNPs showed potent antibacterial activity against the pathogenic bacterium Staphylococcus aureus and antifungal activity against the opportunistic pathogenic yeast Candida albicans, both under planktonic and biofilm growing conditions. Our results indicate that BiNPs represent promising antimicrobial nanomaterials, and this facile synthetic method may allow for further investigation of their activity against a variety of pathogenic microorganisms.

Cu Particles Deposition onto MWCNTs by Chemical Reaction

2011 ◽  
Vol 695 ◽  
pp. 211-214 ◽  
Author(s):  
Gue Serb Cho ◽  
Jung Kyu Lim ◽  
Hoon Jang ◽  
Kyeong Hwan Choe ◽  
Won Sik Lee
Keyword(s):  
Chemical Reaction ◽  
Chloride Solution ◽  
Copper Chloride ◽  
Chemical Reduction ◽  
Reduction Process ◽  
Cu Nanoparticles ◽  
Composite Powders ◽  
Reaction Method ◽  
Cnts Surface ◽  
Chemical Reaction Method

CNTs were decorated with Cu particles to decrease floatation of CNTs and improve the wettability between CNTs and Al melt by chemical reaction method. The as-received size of multi-wall CNTs with 99.5% purity was 10~20nm in diameter and 20um in length. Before Cu deposition, the purified CNTs were suspended in solvent solution and ultrasonically stirred to improve the dispersion of CNTs in the copper chloride solution. The metallic Zn and Zn/CNTs composite powders were added into the suspension to precipitate Cu onto the CNTs surface. The Cu deposited CNTs have been characterized in respect of dispersion and size changes of CNTs and Cu particles with field emission scanning electron microscopy(FESEM). The deposited Cu particles onto the CNTs surface were in the range of 100~300nm in diameter. Also, the application of high ultrasonic treatment improved the full coverage of CNTs surface with Cu nanoparticles. From this study, the multi-wall CNTs have been deposited and embedded with Cu particles by chemical reduction process.

scholarly journals Green Solid-State Chemical Reduction of Graphene Oxide Supported on a Paper Substrate

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 693
Author(s):  
Angela Longo ◽  
Mariano Palomba ◽  
Gianfranco Carotenuto
Keyword(s):  
Graphene Oxide ◽  
Solid State ◽  
Chemical Reduction ◽  
Low Cost ◽  
Reduction Process ◽  
Thermal Reduction ◽  
Conversion Degree ◽  
Reduction Techniques ◽  
Reduction Methods ◽  
State Chemical

The reduction of graphene oxide (GO) thin films deposited on substrates is crucial to achieve a technologically useful supported graphene material. However, the well-known thermal reduction process cannot be used with thermally unstable substrates (e.g., plastics and paper), in addition photo-reduction methods are expensive and only capable of reducing the external surface. Therefore, solid-state chemical reduction techniques could become a convenient approach for the full thickness reduction of the GO layers supported on thermally unstable substrates. Here, a novel experimental procedure for quantitative reduction of GO films on paper by a green and low-cost chemical reductant (L-ascorbic acid, L-aa) is proposed. The possibility to have an effective mass transport of the reductant inside the swelled GO solid (gel-phase) deposit was ensured by spraying a reductant solution on the GO film and allowing it to reflux in a closed microenvironment at 50 °C. The GO conversion degree to reduced graphene oxide (r-GO) was evaluated by Fourier transform infrared spectroscopy (FT-IR) in attenuated total reflectance (ATR) mode and X-ray Diffraction (XRD). In addition, morphology and wettability of GO deposits, before and after reduction, were confirmed by digital USB microscopy, scanning electron microscopy (SEM), and contact angle measurements. According to these structural characterizations, the proposed method allows a bulky reduction of the coating but leaves to a GO layer at the interface, that is essential for a good coating-substrate adhesion and this special characteristic is useful for industrial exploitation of the material.

Fabrication of TiO2/Ag/Ag2O Nanoparticles to Enhance the Photocatalytic Activity of Degussa P25 Titania

2016 ◽  
Vol 69 (1) ◽  
pp. 41 ◽  
Author(s):  
Safyan A. Khan ◽  
Shahid Ali ◽  
Manzar Sohail ◽  
Mohamed A. Morsy ◽  
Zain H. Yamani
Keyword(s):  
Chemical Reduction ◽  
Visible Region ◽  
Spherical Shape ◽  
Ag Nps ◽  
X Ray ◽  
Transmission Electron ◽  
Silver Nps ◽  
Degussa P25 ◽  
Average Size ◽  
Ag2o Nanoparticles

A simple chemical reduction approach was used to synthesize Ag nanoparticles (NPs) over a reputed photocatalyst, Degussa P25 (TiO2). Silver doping extended the P25 absorption wavelength from the ultraviolet to the visible region. The synthesized silver NPs (Ag NPs) were of spherical shape and had an average size of ~4.6 nm. In the next stage, Ag NPs were partially oxidized by treatment with hydrogen peroxide. The resulting P25/Ag/Ag2O nanocomposites were characterized by X-ray powder diffraction, transmission electron microscopy, energy dispersive X-ray analysis, Brunauer–Emmett–Teller analysis, and UV-visible spectroscopy. The photocatalytic activities of the P25, P25/Ag, and P25/Ag/Ag2O catalysts were investigated for the degradation of non-biodegradable dyes, methylene blue and rhodamine 6G. The P25/Ag/Ag2O nanocomposite exhibited better photodegradation activity than P25, as well as the commonly used Ag3PO4, under visible light irradiation.

Preparation of TiC/W core–shell structured powders by one-step activation and chemical reduction process

2015 ◽  
Vol 619 ◽  
pp. 704-708 ◽  
Author(s):  
Xiao-Yu Ding ◽  
Lai-Ma Luo ◽  
Li-Mei Huang ◽  
Guang-Nan Luo ◽  
Xiao-Yong Zhu ◽  
...  
Keyword(s):  
Chemical Reduction ◽  
Reduction Process ◽  
Core Shell ◽  
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