Enhancement of Au Nanoparticles Formed by in Situ Electrodeposition on Direct Electrochemistry of Myoglobin Loaded into Layer-by-Layer Films of Chitosan and Silica Nanoparticles

2008 ◽  
Vol 112 (48) ◽  
pp. 15513-15520 ◽  
Author(s):  
Xihong Guo ◽  
Dong Zheng ◽  
Naifei Hu
Keyword(s):  
Silica Nanoparticles ◽  
Au Nanoparticles ◽  
Direct Electrochemistry ◽  
Layer By Layer

Epitaxial growth manner and structure of superconducting oxide films

1990 ◽  
Vol 48 (4) ◽  
pp. 2-3
Author(s):  
Yoshichika Bando ◽  
Takahito Terashima ◽  
Kenji Iijima ◽  
Kazunuki Yamamoto ◽  
Kazuto Hirata ◽  
...  
Keyword(s):  
Ultrathin Films ◽  
Film Surface ◽  
High Energy ◽  
Epitaxial Films ◽  
Layer By Layer ◽  
Initial Growth ◽  
In Situ Growth ◽  
High Quality ◽  
Activated Reactive Evaporation

The high quality thin films of high-Tc superconducting oxide are necessary for elucidating the superconducting mechanism and for device application. The recent trend in the preparation of high-Tc films has been toward “in-situ” growth of the superconducting phase at relatively low temperatures. The purpose of “in-situ” growth is to attain surface smoothness suitable for fabricating film devices but also to obtain high quality film. We present the investigation on the initial growth manner of YBCO by in-situ reflective high energy electron diffraction (RHEED) technique and on the structural and superconducting properties of the resulting ultrathin films below 100Å. The epitaxial films have been grown on (100) plane of MgO and SrTiO, heated below 650°C by activated reactive evaporation. The in-situ RHEED observation and the intensity measurement was carried out during deposition of YBCO on the substrate at 650°C. The deposition rate was 0.8Å/s. Fig. 1 shows the RHEED patterns at every stage of deposition of YBCO on MgO(100). All the patterns exhibit the sharp streaks, indicating that the film surface is atomically smooth and the growth manner is layer-by-layer.

Oblique-incidence Reflectivity Difference (OI-RD) and Leed Studies of Adsorption and Growth of Xe on Nb(110)

2003 ◽  
Vol 780 ◽  
Author(s):  
P. Thomas ◽  
E. Nabighian ◽  
M.C. Bartelt ◽  
C.Y. Fong ◽  
X.D. Zhu
Keyword(s):  
Transition Layer ◽  
Layer Growth ◽  
Flow Mode ◽  
Layer By Layer ◽  
Zeroth Order ◽  
Step Flow ◽  
Low Energy Electron Diffraction ◽  
Oriented Film ◽  
Low Energy Electron

AbstractWe studied adsorption, growth and desorption of Xe on Nb(110) using an in-situ obliqueincidence reflectivity difference (OI-RD) technique and low energy electron diffraction (LEED) from 32 K to 100 K. The results show that Xe grows a (111)-oriented film after a transition layer is formed on Nb(110). The transition layer consists of three layers. The first two layers are disordered with Xe-Xe separation significantly larger than the bulk value. The third monolayer forms a close packed (111) structure on top of the tensile-strained double layer and serves as a template for subsequent homoepitaxy. The adsorption of the first and the second layers are zeroth order with sticking coefficient close to one. Growth of the Xe(111) film on the transition layer proceeds in a step flow mode from 54K to 40K. At 40K, an incomplete layer-by-layer growth is observed while below 35K the growth proceeds in a multilayer mode.

scholarly journals Cylindrical Microparticles Composed of Mesoporous Silica Nanoparticles for the Targeted Delivery of a Small Molecule and a Macromolecular Drug to the Lungs: Exemplified with Curcumin and siRNA

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 844
Author(s):  
Thorben Fischer ◽  
Inga Winter ◽  
Robert Drumm ◽  
Marc Schneider
Keyword(s):  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Targeted Delivery ◽  
Mesoporous Silica Nanoparticles ◽  
Alveolar Epithelial Cells ◽  
In Vitro Toxicity ◽  
Layer By Layer ◽  
Necrosis Factor Alpha ◽  
Aerodynamic Properties ◽  
Tnf Α

The transport of macromolecular drugs such as oligonucleotides into the lungs has become increasingly relevant in recent years due to their high potency. However, the chemical structure of this group of drugs poses a hurdle to their delivery, caused by the negative charge, membrane impermeability and instability. For example, siRNA to reduce tumour necrosis factor alpha (TNF-α) secretion to reduce inflammatory signals has been successfully delivered by inhalation. In order to increase the effect of the treatment, a co-transport of another anti-inflammatory ingredient was applied. Combining curcumin-loaded mesoporous silica nanoparticles in nanostructured cylindrical microparticles stabilized by the layer-by-layer technique using polyanionic siRNA against TNF-α was used for demonstration. This system showed aerodynamic properties suited for lung deposition (mass median aerodynamic diameter of 2.85 ± 0.44 µm). Furthermore, these inhalable carriers showed no acute in vitro toxicity tested in both alveolar epithelial cells and macrophages up to 48 h incubation. Ultimately, TNF-α release was significantly reduced by the particles, showing an improved activity co-delivering both drugs using such a drug-delivery system for specific inhibition of TNF-α in the lungs.

In Situ Exsolved Au Nanoparticles from Perovskite Oxide for Efficient Epoxidation of Styrene

2021 ◽  
Author(s):  
Yang Gao ◽  
Xing Chen ◽  
Shuqi Hu ◽  
Shiguo Zhang
Keyword(s):  
Density Functional Theory ◽  
Thermodynamic Analysis ◽  
Density Functional ◽  
Au Nanoparticles ◽  
Oxide Catalyst ◽  
Density Functional Theory Calculations ◽  
Average Diameter ◽  
Perovskite Oxide ◽  
Functional Theory

Au-doped SrTiO3 perovskite oxide catalyst (Sr0.995Au0.005TiO3-δ) has been designed and synthesized based on thermodynamic analysis and density functional theory calculations. During reduction, Au nanoparticles with an average diameter of 2...

In situ switching layer-by-layer assembly: one-pot rapid layer assembly via alternation of reductive and oxidative electropolymerization

2013 ◽  
Vol 49 (61) ◽  
pp. 6879 ◽  
Author(s):  
Mao Li ◽  
Jian Zhang ◽  
Hai-Jing Nie ◽  
Meiyong Liao ◽  
Liwen Sang ◽  
...  
Keyword(s):  
Layer By Layer ◽  
One Pot ◽  
Layer By Layer Assembly ◽  
Layer Assembly ◽  
Switching Layer

scholarly journals In-Situ XPS Monitoring and Characterization of Electrochemically Prepared Au Nanoparticles in an Ionic Liquid

ACS Omega ◽  
2017 ◽  
Vol 2 (2) ◽  
pp. 478-486 ◽  
Author(s):  
Merve T. Camci ◽  
Burak Ulgut ◽  
Coskun Kocabas ◽  
Sefik Suzer
Keyword(s):  
Ionic Liquid ◽  
Au Nanoparticles ◽  
In Situ Xps

Rheed Studies of a-Axis Oriented DyBa2Cu3O7 Films Grown by All-MBE

1997 ◽  
Vol 502 ◽  
Author(s):  
Ivan Bozovic ◽  
J. N. Eckstein ◽  
Natasha Bozovic ◽  
J. O'Donnell
Keyword(s):  
Phase Transitions ◽  
Secondary Phase ◽  
Atomic Layer ◽  
High Energy ◽  
Layer By Layer ◽  
Growth Modes ◽  
Flow Surface ◽  
Surface Phase Transitions

ABSTRACTReal-time, in-situ surface monitoring by reflection high-energy electron diffraction (RHEED) has been the key enabling component of atomic-layer-by-layer molecular beam epitaxy (ALL-MBE) of complex oxides. RHEED patterns contain information on crystallographic arrangements and long range order on the surface; this can be made quantitative with help of numerical simulations. The dynamics of RHEED patterns and intensities reveal a variety of phenomena such as nucleation and dissolution of secondary-phase precipitates, switching between growth modes (layer-by-layer, step-flow), surface phase transitions (surface reconstruction, roughening, and even phase transitions induced by the electron beam itself), etc. Some of these phenomena are illustrated here, using as a case study our recent growth of atomically smooth a-axis oriented DyBa2Cu3O7 films.

Fabrication of Polycrystalline Silicon on Glass from Fluorinated Precursors with the Aid of Atomic Hydrogen

1995 ◽  
Vol 403 ◽  
Author(s):  
T. Akasaka ◽  
D. He ◽  
I. Shimizu
Keyword(s):  
Thin Films ◽  
Atomic Hydrogen ◽  
Polycrystalline Silicon ◽  
In Situ Observation ◽  
Layer By Layer ◽  
High Quality ◽  
Deposition Parameters ◽  
Columnar Grains ◽  
Step Growth

AbstractHigh quality polycrystalline silicon was made on glass from fluorinated precursors by two step growth, i.e., (1) formation of seed crystals on glass by layer-by-layer(LL) technique and (2) grain-growth on the seeds. In LL technique, deposition of ultra-thin films and treatment with atomic hydrogen was repeated alternately. Columnar grains with 200 nm dia were grown epitaxy-like on the seeds by optimizing the deposition parameters under in situ observation with spectroscopic ellipsometry.

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