scholarly journals Impact of Specifically Adsorbing Anions on the Electroless Growth of Gold Nanotubes

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Falk Muench ◽  
Cornelia Neetzel ◽  
Stefan Lauterbach ◽  
Hans-Joachim Kleebe ◽  
Wolfgang Ensinger
Keyword(s):  
Thin Films ◽  
Gold Nanoparticles ◽  
Reaction Rate ◽  
Porous Structures ◽  
Gold Plating ◽  
Reaction Conditions ◽  
Aspect Ratios ◽  
Polymer Templates ◽  
Metal Nanotubes ◽  
Enhanced Stability

Electroless metal deposition on nanochannel-containing templates is a versatile route towards metal nanotubes and nanowires if the plating reaction can be sufficiently controlled. In this study, disulfitoaurate-formaldehyde-based gold plating baths were modified by the addition of halides, pseudohalides, and EDTA. The introduction of specifically adsorbing anions strongly affected the heterogeneously autocatalyzed plating reaction and allowed the regulation of the reaction rate and the product morphology. The new plating baths showed enhanced stability and allowed the synthesis of homogeneous nanotubes of high aspect ratios (>150) in 30 μm thick ion track-etched polymer templates. Depending on the reaction conditions, solid and porous structures consisting of gold nanoparticles of differing size and shape were accessible. The presented strategy offers adapted gold thin films, nanotubes, and nanowires for applications in catalysis or sensing.

Effect of gold nanoparticles on transmittance and conductance of graphene oxide thin films and efficiency of perovskite solar cells

2019 ◽  
Vol 10 (2) ◽  
pp. 485-497 ◽  
Author(s):  
Muhammad Jawad ◽  
Abdul Faheem Khan ◽  
Amir Waseem ◽  
Afzal Hussain Kamboh ◽  
Muhammad Mohsin ◽  
...  
Keyword(s):  
Thin Films ◽  
Gold Nanoparticles ◽  
Graphene Oxide ◽  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Oxide Thin Films

scholarly journals Optimizing the Reaction Conditions for the Formation of Fumarate via Trans-Hydrogenation

2021 ◽  
Author(s):  
Laura Wienands ◽  
Franziska Theiß ◽  
James Eills ◽  
Lorenz Rösler ◽  
Stephan Knecht ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Thermal Equilibrium ◽  
Reaction Rate ◽  
Low Cost ◽  
Hydrogen Gas ◽  
Metabolic Imaging ◽  
Reaction Conditions ◽  
Precursor Molecule ◽  
Solution Preparation

AbstractParahydrogen-induced polarization is a hyperpolarization method for enhancing nuclear magnetic resonance signals by chemical reactions/interactions involving the para spin isomer of hydrogen gas. This method has allowed for biomolecules to be hyperpolarized to such a level that they can be used for real time in vivo metabolic imaging. One particularly promising example is fumarate, which can be rapidly and efficiently hyperpolarized at low cost by hydrogenating an acetylene dicarboxylate precursor molecule using parahydrogen. The reaction is relatively slow compared to the timescale on which the hyperpolarization relaxes back to thermal equilibrium, and an undesirable 2nd hydrogenation step can convert the fumarate into succinate. To date, the hydrogenation chemistry has not been thoroughly investigated, so previous work has been inconsistent in the chosen reaction conditions in the search for ever-higher reaction rate and yield. In this work we investigate the solution preparation protocols and the reaction conditions on the rate and yield of fumarate formation. We report conditions to reproducibly yield over 100 mM fumarate on a short timescale, and discuss aspects of the protocol that hinder the formation of fumarate or lead to irreproducible results. We also provide experimental procedures and recommendations for performing reproducible kinetics experiments in which hydrogen gas is repeatedly bubbled into an aqueous solution, overcoming challenges related to the viscosity and surface tension of the water.

Submicron Patterned Anodic Oxidation of Aluminum Thin Films

2000 ◽  
Vol 636 ◽  
Author(s):  
Qiyu Huang ◽  
Whye-Kei Lye ◽  
David M. Longo ◽  
Michael L. Reed
Keyword(s):  
Thin Films ◽  
Anodic Oxidation ◽  
Ion Beam ◽  
Electrochemical Anodization ◽  
Optical Methods ◽  
Imprint Lithography ◽  
Aluminum Films ◽  
Aspect Ratios ◽  
Potential Applications ◽  
Nano Imprint

AbstractAlumina formed by the electrochemical anodization of bulk aluminum has a regular porous structure [1]. Sub-100 nm pores with aspect ratios as high as 1000:1 can easily be formed [2] without elaborate processing. Anodization of aluminum thus provides the basis for the inexpensive, high throughput microfabrication of structures with near vertical sidewalls [2]. In this work we explore the patterned anodic oxidation of deposited aluminum thin films, facilitating the integration of this technique with established microfabrication tools. An anodization barrier of polymethylmethacrylate (PMMA) is deposited onto 300 nm thick aluminum films. The barrier film is subsequently patterned and the exposed aluminum anodized in a 10% sulfuric acid solution. Barrier patterning techniques utilized in this study include optical exposure, ion-beam milling and nano-imprint lithography. Sharp edge definition on micron scale patterns has been achieved using optical methods. Extension of this technique to smaller dimensions by ion-beam milling and nano-imprint lithography is presented. We further report on the observation of contrast reversal of anodization with very thin PMMA barriers, which provides a novel means of pattern transfer. Potential applications and challenges will be discussed.

Multilayer SnSb4–SbSe Thin Films for Phase Change Materials Possessing Ultrafast Phase Change Speed and Enhanced Stability

2017 ◽  
Vol 9 (32) ◽  
pp. 27004-27013 ◽  
Author(s):  
Ruirui Liu ◽  
Xiao Zhou ◽  
Jiwei Zhai ◽  
Jun Song ◽  
Pengzhi Wu ◽  
...  
Keyword(s):  
Thin Films ◽  
Phase Change ◽  
Phase Change Materials ◽  
Enhanced Stability

Enhanced stability of ZnTPPS by polymeric gold nanoparticles in acidic aqueous solutions

2016 ◽  
Vol 53 (5) ◽  
pp. 270-275 ◽  
Author(s):  
Zhihua Chai ◽  
Liya Ma ◽  
Yanxia Wang ◽  
Xuejun Ren ◽  
Ming Gao
Keyword(s):  
Gold Nanoparticles ◽  
Aqueous Solutions ◽  
Enhanced Stability

Patterning rubrene crystalline thin films for sub-micrometer channel length field-effect transistor arrays

2014 ◽  
Vol 2 (44) ◽  
pp. 9359-9363 ◽  
Author(s):  
Juan Zhu ◽  
Wenchong Wang ◽  
Qigang Zhong ◽  
Liqiang Li ◽  
Chuan Du ◽  
...  
Keyword(s):  
Thin Films ◽  
Field Effect ◽  
Carrier Mobility ◽  
Field Effect Transistor ◽  
Channel Length ◽  
Organic Films ◽  
Porous Structures ◽  
Patterned Growth ◽  
Effect Transistor ◽  
Magnitude Difference

The patterned growth of crystalline rubrene films directly on electrodes is demonstrated. In addition, organic films with close packed and porous structures are locally achieved by controlling the electrode spaces, resulting in a two orders of magnitude difference in carrier mobility.

scholarly journals Selective synthesis of thioethers in the presence of a transition-metal-free solid Lewis acid

2016 ◽  
Vol 12 ◽  
pp. 2627-2635 ◽  
Author(s):  
Federica Santoro ◽  
Matteo Mariani ◽  
Federica Zaccheria ◽  
Rinaldo Psaro ◽  
Nicoletta Ravasio
Keyword(s):  
Reaction Rate ◽  
Solid Acid ◽  
Amorphous Solid ◽  
Solid Acid Catalysts ◽  
Acid Catalysts ◽  
Alumina Catalyst ◽  
Reaction Conditions ◽  
Solvent Free Conditions ◽  
Wide Range ◽  
Silica Alumina

The synthesis of thioethers starting from alcohols and thiols in the presence of amorphous solid acid catalysts is reported. A silica alumina catalyst with a very low content in alumina gave excellent results in terms of both activity and selectivity also under solvent-free conditions. The reaction rate follows the electron density of the carbinol atom in the substrate alcohol and yields up to 99% and can be obtained for a wide range of substrates under mild reaction conditions.

scholarly journals A Flexible Synthesis of 68Ga-Labeled Carbonic Anhydrase IX (CAIX)-Targeted Molecules via CBT/1,2-Aminothiol Click Reaction

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 23 ◽  
Author(s):  
Kuo-Ting Chen ◽  
Kevin Nguyen ◽  
Christian Ieritano ◽  
Feng Gao ◽  
Yann Seimbille
Keyword(s):  
Carbonic Anhydrase ◽  
Half Life ◽  
Reaction Rate ◽  
Click Reaction ◽  
Tumor Hypoxia ◽  
Carbonic Anhydrase Ix ◽  
Reaction Conditions ◽  
Positron Emitter ◽  
Radiochemical Yields ◽  
Gallium 68

We herein describe a flexible synthesis of a small library of 68Ga-labeled CAIX-targeted molecules via an orthogonal 2-cyanobenzothiazole (CBT)/1,2-aminothiol click reaction. Three novel CBT-functionalized chelators (1–3) were successfully synthesized and labeled with the positron emitter gallium-68. Cross-ligation between the pre-labeled bifunctional chelators (BFCs) and the 1,2-aminothiol-acetazolamide derivatives (8 and 9) yielded six new 68Ga-labeled CAIX ligands with high radiochemical yields. The click reaction conditions were optimized to improve the reaction rate for applications with short half-life radionuclides. Overall, our methodology allows for a simple and efficient radiosynthetic route to produce a variety of 68Ga-labeled imaging agents for tumor hypoxia.

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