Experimental and atomistic study of high speed collisions of gold nanoparticles with a gold substrate: Validation of interatomic potentials

We have developed a “green” method for fabricating gold nanoparticles (AuNPs) through biogenic approaches. The proposed method has the advantages of facile preparation under ecofriendly conditions. AuNPs encapsulated in carbon nanosheets, and exhibiting high thermal stability, were fabricated by autoclaving pectin-capped AuNPs, which were subsequently collected through high-speed centrifugation and redispersed in aqueous solution. The 1,1-diphenyl-2-picrylhydrazy (DPPH) radical scavenging assay indicated that our prepared AuNPs exhibited more prolonged antioxidant capacity than pristine apple extracts. Electron paramagnetic resonance (EPR) spectra showed that approximately 80% of DPPH radicals were scavenged by the pectin-capped AuNPs at a concentration of 3 mg/mL. According to our results, AuNPs prepared through biogenic approaches have potential use in the food industry.

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Preparation of nascent molecular electronic devices from gold nanoparticles and terminal alkyne functionalised monolayer films

Journal of Materials Chemistry C ◽

10.1039/c4tc01080a ◽

2014 ◽

Vol 2 (35) ◽

pp. 7348-7355 ◽

Cited By ~ 27

Author(s):

Henrry M. Osorio ◽

Pilar Cea ◽

Luz M. Ballesteros ◽

Ignacio Gascón ◽

Santiago Marqués-González ◽

...

Keyword(s):

Gold Nanoparticles ◽

Electronic Devices ◽

Terminal Alkyne ◽

Gold Substrate ◽

Molecular Electronic ◽

Monolayer Films ◽

Molecular Electronic Devices

A nascent metal–molecule–GNP assembly has been fabricated by immersion of a gold-substrate supported monolayer in a solution of gold nanoparticles (GNPs).

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Observation of the surface plasmon resonances in gold nanoparticles above a gold substrate and in gold nanoparticle pairs

Technical Digest. CLEO/Pacific Rim 2001. 4th Pacific Rim Conference on Lasers and Electro-Optics (Cat. No.01TH8557) ◽

10.1109/cleopr.2001.967945 ◽

2002 ◽

Author(s):

T. Okamoto ◽

I. Yamaguchi

Keyword(s):

Gold Nanoparticles ◽

Gold Nanoparticle ◽

Surface Plasmon ◽

Gold Substrate ◽

Surface Plasmon Resonances ◽

Plasmon Resonances

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Atomistic Study on Size Effects in Thermally Induced Martensitic Phase Transformation of NiTi

Smart Materials Research ◽

10.1155/2016/7512642 ◽

2016 ◽

Vol 2016 ◽

pp. 1-12 ◽

Cited By ~ 2

Author(s):

Sourav Gur ◽

George N. Frantziskonis

Keyword(s):

Thin Films ◽

Phase Transformation ◽

Size Effects ◽

Martensite Phase ◽

Martensitic Phase ◽

Martensitic Phase Transformation ◽

Phase Fraction ◽

Interatomic Potentials ◽

Thermally Induced ◽

Atomistic Study

The atomistic study shows strong size effects in thermally induced martensitic phase transformation evolution kinetics of equiatomic NiTi shape memory alloys (SMAs). It is shown that size effects are closely related to the presence of free surfaces; thus, NiTi thin films and nanopillars are studied. Quasi-static molecular dynamics simulations for several cell sizes at various (constant) temperatures are performed by employing well-established interatomic potentials for NiTi. The study shows that size plays a crucial role in the evolution of martensite phase fraction and, importantly, can significantly change the phase transformation temperatures, which can be used for the design of NiTi based sensors, actuators, or devices at nano- to microscales. Interestingly, it is found that, at the nanometer scale, Richard’s equation describes very well the martensite phase fraction evolution in NiTi thin films and nanopillars as a function of temperature.

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Polymer electrical bistable device and memory cells

MRS Proceedings ◽

10.1557/proc-830-d7.1 ◽

2004 ◽

Vol 830 ◽

Author(s):

Jianyong Ouyang ◽

Chih-Wei Chu ◽

Ankita Prakash ◽

Yang Yang

Keyword(s):

Gold Nanoparticles ◽

Electric Field ◽

Polymer Film ◽

Nonvolatile Memory ◽

High Speed ◽

Low Cost ◽

Energy Levels ◽

Solution Process ◽

High Conductivity ◽

Reverse Direction

ABSTRACTElectrical bistable states with the conductivity different by more than four orders in magnitude were observed in a polymer film sandwiched between two metal electrodes. This polymer film was composed of gold nanoparticles, 8-hydroxyquinoline and polystyrene, and was formed by a solution process. The film can be programmed between the two electrical states by an electric field. The as-prepared device, which was in a low conductivity state, exhibited an abrupt increase of current when the device was scanned up to 2.8 volt (V). The high conductivity state can be returned to the low conductivity state at a voltage of –1.8 V in the reverse direction. The device has a good stability in both the states. The transitions are nonvolatile, and the transition from the low to the high conductivity state takes place in nanoseconds, so that the device can be used as a low-cost, high-density, high-speed, and nonvolatile memory. The switching mechanism was studied by investigating the current-voltage characteristics, the temperature dependence of the current, the surface potential atomic force microscopy and the energy levels of the materials. The electronic transition is attributed to the electric-field induced charge transfer between the gold nanoparticles and 8-hydroxyquinoline molecules.

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A Molecular Dynamics Study of Short Nanoparticle Chains under Mechanical Strain: Linear and Kinked Configurations

MRS Proceedings ◽

10.1557/proc-821-p6.4 ◽

2004 ◽

Vol 821 ◽

Author(s):

Adamos Dalis ◽

Sheldon K. Friedlander

Keyword(s):

Molecular Dynamics ◽

Mechanical Behavior ◽

High Speed ◽

Mechanical Strain ◽

Quantitative Information ◽

Atomic Scale ◽

Test Material ◽

Interatomic Potentials ◽

Stress Accommodation ◽

Nanoparticle Chains

AbstractPrevious studies in our laboratory have shown that individual nanoparticle chain aggregates (NCA) exhibit remarkable mechanical behavior when under strain inside the transmission electron microscope. NCA made of various materials (e.g. carbon, metal oxides, metals, etc.) were strained by as much as 100% when tension was applied to them. After breaking, the NCA rapidly contracted to form more compact structures. In this study, molecular dynamics (MD) computer simulations are employed to investigate, at the atomic scale, the behavior of short nanoparticle chains under strain and to obtain quantitative information of the forces involved in chain straining and fracturing. The interaction potential used is that of copper obtained with the embedded atom method (EAM). Although the methodology is generally applicable, copper was selected as a test material because reliable interatomic potentials are available. Seven single- crystal nanoparticles, each 2.452 nm in diameter, are placed in contact in two chain configurations, linear and kinked. The structures are initially relaxed adiabatically with MD steps for 225 ps, at a starting temperature of 300 K. The bonding energy between any two nanoparticles in contact ranges from about 20 eV to 30 eV at 0 K. The two relaxed chain configurations are strained along their longest dimension, to the breaking point, at strain rates spanning from 0.3 m/s to 10 m/s. We identify mechanisms of stress accommodation that lead to plastic deformation and eventually fracture for both chain configurations, linear and kinked, and we construct the corresponding stress-strain curves. The two chain configurations exhibit different mechanical behavior. Applications of our experimental and simulation studies on NCA are to the behavior of nanocomposite materials, including carbon black reinforced rubber, sampling of aggregates by high speed impactors and the formation of flexible coatings of nanoparticles.

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