Synthesis and Self-Assembly of Films Containing FeCoPt Nanoparticles

2001 ◽  
Vol 674 ◽  
Author(s):  
Min Chen ◽  
David E. Nikles
Keyword(s):  
Self Assembly ◽  
Annealing Temperature ◽  
Chemical Reduction ◽  
Average Diameter ◽  
Iron Pentacarbonyl ◽  
Face Centered Cubic ◽  
Oxidized Iron ◽  
Carbon Coated ◽  
Face Centered ◽  
Cobalt Acetylacetonate

ABSTRACTFe49Co7Pt44 and Fe40Co17Pt43nanoparticles were synthesized by simultaneous chemical reduction of platinum acetylacetonate and cobalt acetylacetonate and thermal decomposition of iron pentacarbonyl. As-prepared the particles had a disordered face-centered cubic lattice with an average diameter of 3.2 nm and were superparamagnetic. These particles were well dispersed in a 50/50 mixture of hexane and octane. The particles self-assembled into ordered superlattices when deposited onto carbon coated Cu TEM grids or onto single crystal Si (100) substrates. After vacuum annealing (from 500°C to 700 °C), the particles transformed to the tetragonal phase. The coercivity of the film strongly depended on the composition and annealing temperature. For the Fe49Co7Pt44film, coercivity of 8700 Oe and a squareness of 0.75 after annealing at 700 °C for 30 minutes. XPS shows existance of oxidized iron and cobalt on the surface of film.

Effects of Substrates on the Self-Assembling of FePt Nanocrystals

2001 ◽  
Vol 674 ◽  
Author(s):  
Min Chen ◽  
David E. Nikles
Keyword(s):  
Chemical Reduction ◽  
Average Diameter ◽  
Iron Pentacarbonyl ◽  
Fept Nanoparticles ◽  
Hexagonal Close Packed ◽  
Self Assembling ◽  
Hydrocarbon Solvents ◽  
Carbon Coated ◽  
Self Assembled ◽  
Hexagonal Arrays

ABSTRACTFe48Pt52 nanoparticles were synthesized by the simultaneous chemical reduction of platinum acetylacetonate and thermal decomposition of iron pentacarbonyl. As-prepared the particles were spherical with an average diameter of 3 nm and a polydispersity of less than 5%. The particles were superparamagnetic and had a fcc structure. Highly ordered self-assembled supercrystals of particles were formed in TEM grids by deposition from dispersions in hydrocarbon solvents. Nanoparticles deposited on amorphous carbon-coated and SiO2-coated Cu grids tend to assemble into small domains of hexagonal arrays. Larger domains of hexagonal arrays formed on Si3N4 membrane TEM grids. For thin multilayers, the FePt nanoparticles tends to assemble into hexagonal close-packed lattices (ABABAB stacking). For the thicker multilayers, ABCABC stacking was observed. Small angle X-ray reflectivity of the particles on a Si (100) substrate show highly ordered multiplanar structure with d-spacing of 6.2 nm. The coercivity of self-assembled FePt films strongly depended on the annealing temperature. After annealing at 700°C for 30 minutes, the particles transformed from FCC to “FCT” phase and the coercivity of film increased up to 11570 Oe. However, the particle size increased to 16 nm due to sintering.

scholarly journals Synthesis and Study of the Optical Properties of PMMA Microspheres and Opals

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2171
Author(s):  
Mayra Matamoros-Ambrocio ◽  
Enrique Sánchez-Mora ◽  
Estela Gómez-Barojas ◽  
José Alberto Luna-López
Keyword(s):  
Band Gap ◽  
Self Assembly ◽  
Photonic Band Gap ◽  
Average Diameter ◽  
Reflectance Spectra ◽  
Face Centered Cubic ◽  
Indirect Transition ◽  
Specular Reflectance ◽  
Assembly Method ◽  
Face Centered

Polymethylmethacrylate (PMMA) microspheres were synthesized by surfactant-free emulsion polymerization. These microspheres were used to obtain opals by the self-assembly method. Monomer and initiator quantities were varied systematically to monitor the size of PMMA microspheres. From SEM and DLS measurements, a trend was observed showing as the monomer and initiator amounts increased the average diameter of PMMA microspheres increased except when a minimum monomer amount was reached, for which the size of the microspheres remained practically constant. Diffuse reflectance spectra were processed by the Kubelka–Munk treatment to estimate the energy band gap (Eg) of the PMMA microspheres. It was found that PMMA microspheres present an indirect transition. From SEM micrographs, it is seen that PMMA opals photonic crystals are formed by microspheres in a uniform periodic face-centered cubic (fcc) array. Variable-angle specular reflectance spectra show that the opals possess a pseudo photonic band gap (PBG) in the visible and near-IR regions. Furthermore, it was found that PBGs shift towards larger wavelengths as the average diameter of the PMMA microspheres increases.

Structure of Self-assembled Magnetic FePtCu Nanoparticles Arrays

2003 ◽  
Vol 775 ◽  
Author(s):  
Xiangcheng Sun ◽  
J.W. Harrell ◽  
D. E. Nikles ◽  
K. Sun ◽  
L. M. Wang ◽  
...  
Keyword(s):  
Average Diameter ◽  
Iron Pentacarbonyl ◽  
Particle Packing ◽  
Three Dimensions ◽  
Face Centered Cubic ◽  
Oleyl Amine ◽  
Organic Surfactant ◽  
Self Assembled ◽  
Face Centered ◽  
Organic Capping

AbstractIn this study, a series of FexPtyCu100-x-y nanoparticles were chemically synthesized by solution-phase reduction of platinum and copper reagents and thermal decomposition of iron pentacarbonyl in the presence of stabilizers oleic acid and oleyl amine. As-prepared particles had a chemically disordered face-centered cubic (fcc) lattice with an average diameter of 3.5 nm. The particle size, and the corresponding size distribution were controlled by varying the organic surfactant (oleic acids, etc.), its concentration, and the reaction temperature. These particles were well dispersed in hydrocarbon solvents and self-assembled into two or three dimensions particles arrays with a variety of closepacking arrangements. Domain of monolayers, bilayers and multilayers of particles arrays were frequently detected in TEM specimens. Both cubic close-packed (ccp) and honeycomb arrays were also uniquely observed. It was also demonstrated that the controlled organic surfactant layer (organic capping) play a crucial role in determining assembly dimensions and symmetry as well as particle packing arrays.

Synthesis and Fabrication of PVA-Ag-Cu and PANI-Ag-Cu Nanocomposite Thin Film Sensor for Detection of E. coli in Water

2014 ◽  
Vol 911 ◽  
pp. 131-135 ◽  
Author(s):  
H. Abdullah ◽  
Noor Azwen Noor Azmy ◽  
Norshafadzila Mohammad Naim ◽  
Aisyah Bolhan ◽  
Aidil Abdul Hamid ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Reduction ◽  
Oxidative Polymerization ◽  
Face Centered Cubic ◽  
High Concentration ◽  
Film Sensor ◽  
E Coli ◽  
Host Materials ◽  
Face Centered ◽  
Xrd Patterns

Polymers are excellent host materials for nanoparticles of metals and semiconductors. PVAAgCu nanocomposite was synthesized from chemical reduction, whereas PANIAgCu nanocomposite was synthesized by chemical oxidative polymerization. PVAAgCu and PANIAgCu thin films were deposited on the glass substrate by spin coating technique. The films were characterized by using XRD and AFM. The sensitivity of the samples was analyzed by IV measurement. The peaks in XRD patterns confirm the presence of Ag-Cu nanoparticles in face centered cubic structure. AFM images show the roughness of PVAAgCu and PANIAgCu increased as Ag concentration decreased and Cu concentration increased. I-V measurements indicate that the change in the current of the films increases with the presence of E. coli. The sensitivity on E. coli increases for PVAAgCu and PANIAgCu thin films with high concentration of Cu.

scholarly journals Effect of feed supplementation with biosynthesized silver nanoparticles using leaf extract of Morus indica L. V1 on Bombyx mori L. (Lepidoptera: Bombycidae)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sudip Some ◽  
Onur Bulut ◽  
Kinkar Biswas ◽  
Anoop Kumar ◽  
Anupam Roy ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Bombyx Mori ◽  
Leaf Extract ◽  
Silver Ions ◽  
Average Diameter ◽  
Face Centered Cubic ◽  
Tem Analysis ◽  
Beneficial Effects ◽  
Selected Area Electron Diffraction ◽  
Face Centered

Abstract Herein, we report the synthesis of silver nanoparticles (AgNPs) by a green route using the aqueous leaf extract of Morus indica L. V1. The synthesized AgNPs exhibited maximum UV-Vis absorbance at 460 nm due to surface plasmon resonance. The average diameter (~54 nm) of AgNPs was measured from HR-TEM analysis. EDX spectra also supported the formation of AgNPs, and negative zeta potential value (−14 mV) suggested its stability. Moreover, a shift in the carbonyl stretching (from 1639 cm−1 to 1630 cm−1) was noted in the FT-IR spectra of leaf extract after AgNPs synthesis which confirm the role of natural products present in leaves for the conversion of silver ions to AgNPs. The four bright circular rings (111), (200), (220) and (311) observed in the selected area electron diffraction pattern are the characteristic reflections of face centered cubic crystalline silver. LC-MS/MS study revealed the presence of phytochemicals in the leaf extract which is responsible for the reduction of silver ions. MTT assay was performed to investigate the cytotoxicity of AgNPs against two human cell lines, namely HepG2 and WRL-68. The antibacterial study revealed that MIC value of the synthesized AgNPs was 80 µg/ml against Escherichia coli K12 and Staphylococcus aureus (MTCC 96). Finally, the synthesized AgNPs at 10 µg/ml dosages showed beneficial effects on the survivability, body weights of the Bombyx mori L. larvae, pupae, cocoons and shells weights via enhancing the feed efficacy.

scholarly journals Exploration of the Antimicrobial and Catalytic Properties of Gold Nanoparticles Greenly Synthesized by Cryptolepis buchanani Roem. and Schult Extract

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Kamonpan Wongyai ◽  
Phitchayapak Wintachai ◽  
Rasimate Maungchang ◽  
Parawee Rattanakit
Keyword(s):  
Staphylococcus Aureus ◽  
Gold Nanoparticles ◽  
Analytical Techniques ◽  
Average Diameter ◽  
Face Centered Cubic ◽  
Tem Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Face Centered

A green, simple, and rapid synthesis of gold nanoparticles using plant extract, Cryptolepis buchanani Roem. and Schult, and their applications are first described in this paper. The formation of gold nanoparticles was visually observed by the appearance of a ruby red color, which was further indicated by an absorption peak at 530 nm in UV-Vis spectroscopy. Optimization of reaction parameters for the gold nanoparticles was also investigated. Various analytical techniques were employed as part of the process of characterizing the resulting gold nanoparticles. Fourier transform infrared (FTIR) analysis revealed that the phenol compounds present in the extract were responsible for gold(III) reduction and stabilization of gold nanoparticles. Transmission electron microscopy (TEM) analysis showed that the gold nanoparticles were spherical in shape with an average diameter of 11 nm. Powder X-ray diffraction (XRD) pattern indicated that the green synthesis approach produced highly crystalline, face-centered cubic gold nanoparticles. Energy-dispersive X-ray spectroscopy (EDS) measurements confirmed the presence of elemental gold in the prepared nanoparticles. The negative zeta potential value of gold nanoparticles was found to be -30.28 mV. The green synthesized gold nanoparticles expressed effective antibacterial activity against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and Acinetobacter baumannii and exhibited an excellent catalytic property in terms of its reduction ability of methylene blue.

Carbon coated face-centered cubic Ru–C nanoalloys

Nanoscale ◽  
2014 ◽  
Vol 6 (17) ◽  
pp. 10370 ◽  
Author(s):  
Zhisheng Zhao ◽  
Chuanmin Meng ◽  
Peifang Li ◽  
Wenjun Zhu ◽  
Qianqian Wang ◽  
...  
Keyword(s):  
Face Centered Cubic ◽  
Carbon Coated ◽  
Face Centered

scholarly journals Synthesis and characterization of nanostructured CeO2 with dyes adsorption property

2014 ◽  
Vol 8 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Oman Zuas ◽  
Haznan Abimanyu ◽  
Widayanti Wibowo
Keyword(s):  
Aqueous Solution ◽  
Organic Dyes ◽  
Adsorption Property ◽  
Average Diameter ◽  
Precipitation Method ◽  
Face Centered Cubic ◽  
Experimental Conditions ◽  
Face Centered ◽  
Fcc Phase ◽  
Dyes Adsorption

The nanostructured cerium dioxide (CeO2) has been successfully fabricated using a simple precipitation method. Its characteristics were evaluated using TG-DTA, DR-UV-Vis, XRD, FTIR and TEM. The results showed that the nanostructured CeO2 has high purity and good crystalline nature, with face centered cubic (fcc) phase and the average diameter of CeO2 single crystal about 14 nm. Performance evaluation of the synthesized CeO2 samples showed that the nanostructured CeO2 has a strong adsorption toward acid orange-10 (AO-10) and congo red (CR) in aqueous solution. Under given experimental conditions (dye concentration of 15 mg/l, adsorbent dosage of 1 g/l, reaction temperature of 30 ? 1?C), it was estimated that the adsorption equilibrium for AO-10 and CR occurred at 60 min and 90 min of reaction time, respectively, with total removal of 96.82% for AO-10 dye and 93.55% for CR dye. The results suggested that the CeO2 nanopowder could be potentially used as an efficient adsorbent for the removal of synthetic organic dyes in aqueous solution and may address for future concern in the area.

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