In Situ TEM Study of DNA/Gold Nanoparticles in Liquid Environment

1999 ◽  
Vol 5 (S2) ◽  
pp. 340-341
Author(s):  
W.-A Chiou ◽  
R. C. Mucic ◽  
A. Ishikawa ◽  
H. Konishi ◽  
K. Fukushima ◽  
...  
Keyword(s):  
Au Nanoparticles ◽  
High Vacuum ◽  
Functional Materials ◽  
Building Blocks ◽  
Au Nanoparticle ◽  
Natural State ◽  
In Situ Tem ◽  
Liquid Environment ◽  
Colloidal Au

In recent years the assembly of nanometer sized building blocks into two- and three-dimentional structures and functional materials has been an extremely active area of scientific research. A new class of materials, the DNA/nanoparticle hybrid materials and assemblies, which might have useful electrical, optical and structural properties, have been developed at Northwestern University. While characterizing particle morphology (size and shape) by subjecting it to the high vacuum environment in an electron microscope, the structure may have changed drastically from its natural state. The study of morphology of these DNA/Au nanoparticles in the liquid state was thus undertaken to further our understanding of the dynamics of the nanoparticles in a specific environment. This paper presents an in-situ observation of DNA/Au nanoparticle assembles in liquid media using environmental TEM.Experiments were carried out with citrate-stabilized colloidal Au particles averaging 8 and 31 nm in diameter. Colloidal Au nanoparticles were obtained from a commercial source. 8 nm particles were modified with propylthiol-capped oligonucleotide, 3’HS(CH2)3-O(O)P(O)O-ATG-CTC-AAC-TCT, 1,whereas the 31 nm particles were modified with hexlylthiol-capped oligonucleotide, 3’TAG-GAC-TTA-CGC-O(O)P(O )O-(CH2)6SH, 2.

In-Situ UHV TEM Investigations of the Initial Stages of Cu(001) Oxidation

1997 ◽  
Vol 3 (S2) ◽  
pp. 583-584
Author(s):  
J. C. Yang ◽  
M. Yeadon ◽  
B. Kolasa ◽  
J. M. Gibson
Keyword(s):  
High Vacuum ◽  
Copper Film ◽  
Ultra High Vacuum ◽  
Native Oxide ◽  
In Situ Tem ◽  
Face Centered Cubic ◽  
Free Standing ◽  
Transmission Electron ◽  
Face Centered

We studied the beginning oxidation stage of a model metal system by in-situ transmission electron microscopy (TEM) in order to gain insights into the initial kinetics of oxidation. In-situ TEM experiments can distinguish between nucleation and growth since individual oxide islands are imaged. We chose to investigate Cu, since it is a simple face-centered cubic metal. Also, Cu is a highly promising metal interconnect material because of its low resistivity and good electromigration properties as compared to Al.Single crystal -1000Å 99.999% purity copper films were grown on irradiated NaCl in an UHV e-beam evaporator system. The free-standing copper film was placed on a specially designed holder, which permits resistive heating of the sample. The microscope used for this experiment is a modified ultra-high vacuum, with base pressure of 10−9 torr, JEOL200CX, operated at l00kV. To remove the native oxide formed during exposure in air, the Cu film was annealed at ∼350°C

Electrosynthesis of diphenyl carbonate by homogeneous Pd electrocatalysts using Au nanoparticles on graphene as efficient anodes

2016 ◽  
Vol 6 (15) ◽  
pp. 6002-6010 ◽  
Author(s):  
Ryoichi Kanega ◽  
Hitoshi Ogihara ◽  
Ichiro Yamanaka
Keyword(s):  
Au Nanoparticles ◽  
Au Nanoparticle ◽  
Diphenyl Carbonate ◽  
Au Nps

Electrochemical carbonylation of phenol (PhOH) with CO (1 atm) to form diphenyl carbonate (DPC) was studied by using a Pd-(in situ NHC) electrocatalyst and graphene-supported Au nanoparticle (Au NPs/GR) anodes.

Self-Assembled Cobalt Oxide Nanocrystals with Tetrahedral Shape

1998 ◽  
Vol 4 (S2) ◽  
pp. 736-737
Author(s):  
J.S. Yin ◽  
Z.L. Wang
Keyword(s):  
Cobalt Oxide ◽  
Materials Science ◽  
Surface Active Agent ◽  
Active Agent ◽  
Vertical Direction ◽  
Building Blocks ◽  
Research Field ◽  
In Situ Tem ◽  
Small Magnetic Field

Nanocrystal materials are an emerging research field of chemistry, physics and materials science. The size and shape specificity of nanocrystals suggests them as building blocks for constructing selfassembly passivated nanocrystals superlattices (NCS's) or nanocrystals arrays (NCA) [1-6]. In this paper, NCAs of CoO with controlled tetrahedral shape are reported and their structural stability is examined by in-situ TEM.Cobalt oxide nanocrystals were synthesized by chemical decomposition of Co2(CO)8 in toluene under oxygen atmosphere, as given in detail elsewhere [1].Sodium bis(2-ethylhexyl) sulfosuccinate (Na(AOT)) was added as a surface active agent, forming an ordered monolayer passivation (called the thiolate) over the nanocrystal surface. The particle size was controlled by adjusting the wt.% ratio between the precursor and Na(AOT). The as-prepared solution contained Co, CoO and possibly C03O4 nanoparticles, and pure CoO nanoparticles were separated by applying a small magnetic field, which is generated by a horseshoe permanent magnet in vertical direction.

On the Mechanism of Resistive Switching in MIM Capacitors – An Approach with In-situ TEM Experiments

2005 ◽  
Vol 907 ◽  
Author(s):  
Herbert Schroeder
Keyword(s):  
Resistive Switching ◽  
High Vacuum ◽  
Film Structure ◽  
Ex Situ ◽  
In Situ Tem ◽  
Ion Milling ◽  
Window Technique ◽  
Set Up ◽  
Mim Capacitors

AbstractIn this contribution an in-situ TEM experiment is suggested to observe the microstructure of a metal/oxide insulator/metal (MIM) capacitor structure during resistive switching due to an applied external voltage or current. The motivation for such an experiment is the fact that there is a large pool on the resistive switching data in the literature, but there is no agreement on the mechanism, which in part is due to missing microstructural observations of the effects. For such an experiment a special TEM sample holder has been developed allowing controlled in-situ application of temperature (RT to 300°C) with a heating stage and of voltage (current) as a part of a 4-terminal resistance measurement set-up. This is combined with a special TEM sample preparation method, the “window”-technique, so that no thinning of the MIM thin film structure is necessary at all (which is an advantage as the oxides are known to be very sensitive to damage introduced by methods such as ion-milling). Special electrode configurations have been designed to allow nearly undisturbed TEM observation of the switching insulator. Identical samples will also be investigated ex-situ in conventional switching experiments to identify the influence of the special TEM environment (high vacuum, irradiation with energetic electrons).

In situ TEM Investigation on Rotation and Coalescence Behaviors of Au Nanoparticles on h-BN Substrate

2019 ◽  
Vol 25 (S2) ◽  
pp. 1484-1485
Author(s):  
Boao Song ◽  
Yifei Yuan ◽  
Ramin Rojaee ◽  
Reza Shahbazian-Yassar
Keyword(s):  
Au Nanoparticles ◽  
In Situ Tem

Modifiable diyne-based covalent organic framework: a versatile platform for in situ multipurpose functionalization

RSC Advances ◽  
2016 ◽  
Vol 6 (45) ◽  
pp. 39150-39158 ◽  
Author(s):  
Chiyao Bai ◽  
Meicheng Zhang ◽  
Bo Li ◽  
Xiaosheng Zhao ◽  
Shuang Zhang ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Active Sites ◽  
Functional Materials ◽  
Building Blocks ◽  
Covalent Organic Framework ◽  
Organic Framework

A COF material (TCD) containing diynes as both building blocks and active sites was prepared by microwave irradiation and employed as a versatile platform for the preparation of diverse functional materials.

In situ TEM ion irradiation and implantation effects on Au nanoparticle morphologies

2014 ◽  
Vol 50 (57) ◽  
pp. 7593 ◽  
Author(s):  
Daniel Bufford ◽  
Sarah H. Pratt ◽  
Timothy J. Boyle ◽  
Khalid Hattar
Keyword(s):  
Ion Irradiation ◽  
Au Nanoparticle ◽  
In Situ Tem

scholarly journals Improved, Odorless Access to Benzo[1,2-d;4,5-d′]- bis[1,3]dithioles and Tert-butyl Arylsulfides via C-S Cross Coupling

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3666
Author(s):  
Kevin Kopp ◽  
Olav Schiemann ◽  
Nico Fleck
Keyword(s):  
Lewis Acids ◽  
Fluorescent Dyes ◽  
Palladium Catalysis ◽  
Functional Materials ◽  
Building Blocks ◽  
Subsequent Formation ◽  
Tert Butyl ◽  
High Yields ◽  
Aryl Sulfides

Benzo[1,2-d;4,5-d′]bis[1,3]dithioles are important building blocks within a range of functional materials such as fluorescent dyes, conjugated polymers, and stable trityl radicals. Access to these is usually gained via tert-butyl aryl sulfides, the synthesis of which requires the use of highly malodorous tert-butyl thiol and relies on SNAr-chemistry requiring harsh reaction conditions, while giving low yields. In the present work, S-tert-butyl isothiouronium bromide is successfully applied as an odorless surrogate for tert-butyl thiol. The C-S bond formation is carried out under palladium catalysis with the thiolate formed in situ resulting in high yields of tert-butyl aryl sulfides. The subsequent formation of benzo[1,2-d;4,5-d′]bis[1,3]dithioles is here achieved with scandium(III)triflate, a less harmful reagent than the usually used Lewis acids, e.g., boron trifluoride or tetrafluoroboric acid. This enables a convenient and environmentally more compliant access to high yields of benzo[1,2-d;4,5-d′]bis[1,3]dithioles.

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