scholarly journals Electrophoretic Deposition of WS2 Flakes on Nanoholes Arrays—Role of Used Suspension Medium

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3286 ◽  
Author(s):  
Dario Mosconi ◽  
Giorgia Giovannini ◽  
Nicolò Maccaferri ◽  
Michele Serri ◽  
Stefano Agnoli ◽  
...  

Here we optimized the electrophoretic deposition process for the fabrication of WS2 plasmonic nanohole integrated structures. We showed how the conditions used for site-selective deposition influenced the properties of the deposited flakes. In particular, we investigated the effect of different suspension buffers used during the deposition both in the efficiency of the process and in the stability of WS2 flakes, which were deposited on an ordered arrays of plasmonic nanostructures. We observed that a proper buffer can significantly facilitate the deposition process, keeping the material stable with respect to oxidation and contamination. Moreover, the integrated plasmonic structures that can be prepared with this process can be applied to enhanced spectroscopies and for the preparation of 2D nanopores.

2019 ◽  
Vol 18 (03n04) ◽  
pp. 1940087
Author(s):  
A. Panarin ◽  
P. Mojzes ◽  
B. Ranishenka ◽  
S. Terekhov

The degradation of the Surface-enhanced Raman scattering (SERS) signal under laser illumination during spectral measurements is typically observed. To improve the stability of the SERS spectra intensity, hybrid plasmonic structures involving graphene-based protective layers were formed. An observation of the time evolution of the characteristic peak from analyte molecules indicates that the graphene coating can be used to improve the stability of the SERS signal.


2012 ◽  
Vol 507 ◽  
pp. 27-34
Author(s):  
Xin Ming Su ◽  
Ai Ying Wu ◽  
Paula M. Vilarinho

A successful electrophoretic deposition (EPD) markedly depends on the stability of the suspension. In this study the role of Triethanolamine (TEA) as a stabilizer in EPD of thick films of TiTe3O8 is presented. TiTe3O8 powders were synthesized via a conventional solid-state-reaction method and dispersed in acetone with and without TEA. The stability of the suspensions was addressed by zeta-potential, UV light and FTIR measurements. The specific adsorption of TEA to TiTe3O8 particles results in a high zeta potential and improved stability of the suspensions, allowing the preparation of high quality TiTe3O8 thick films on Pt coated Si substrates. TiTe3O8 films sintered at 700 °C are dense and homogeneous.


2009 ◽  
Vol 412 ◽  
pp. 183-188
Author(s):  
Mehdi Javidi ◽  
Sirus Javadpour ◽  
Mohammad Ebrahim Bahrololoom ◽  
Jan Ma

Natural hydroxyapatite has been electrophoretically deposited on medical grade 316L stainless steel. Stable suspensions were prepared by mixing 40 g/L milled natural hydroxyapatite powder in isopropyl alcohol and stabilized by polyethylenimine as dispersing agent and binder. The stability of suspensions was investigated by measuring zeta potential. It was found here that the suspension which was stabilized with 4 g/L polyethylenimine revealed a high value of zeta potential and stability. Deposition was achieved on the cathode at constant voltages of 30, 60, and 90 V for 1 to 5 minutes. After deposition, the samples were dried at room temperature for 24 hours and deposition weight, roughness, and thickness of the coatings were measured. The surface morphology of the coated samples was studied by a scanning electron microscope. The results of the electrophoretic deposition process showed that the sample coated at 60 V and 3 minutes led to an adherent, continuous, and crack-free coating. The coating efficiency and thickness increased with increasing deposition time and yielded to saturation at the constant applied voltage. Also, the current density decreased and yielded to saturation at the constant applied voltage during electrophoretic deposition.


2016 ◽  
Vol 50 (29) ◽  
pp. 4057-4063
Author(s):  
Shanshan Xiao ◽  
Hui Mei ◽  
Qianglai Bai ◽  
Daoyang Han ◽  
Laifei Cheng

The effect of carbon nanotubes introduced by electrophoretic deposition on the tensile behavior of carbon fiber tow was investigated. As-received and heat-treated carbon fiber tows that deposited with carbon nanotubes and their counterparts were tested under monotonous tensile loading. Morphology and presence state of carbon nanotubes on the surface of carbon fiber tows were observed for determining the role of carbon nanotubes. Results showed that tensile properties of carbon fiber tow were not damaged by the electrophoretic deposition process. Due to the uniformly distributed carbon nanotubes network on the surface of carbon fiber tow, the fracture of filaments were obviously constrained by carbon nanotubes instead of instantaneous separation. What’s more, carbon nanotubes exhibited a stronger confining ability for heat-treated carbon fiber tow and improved their tensile properties significantly.


2007 ◽  
Vol 22 (7) ◽  
pp. 1767-1774 ◽  
Author(s):  
M.N. van den Donker ◽  
B. Rech ◽  
R. Schmitz ◽  
J. Klomfass ◽  
G. Dingemans ◽  
...  

The effect of process parameters on the plasma deposition of μc-Si:H solar cells is reviewed in this article. Several in situ diagnostics are presented, which can be used to study the process stability as an additional parameter in the deposition process. The diagnostics were used to investigate the stability of the substrate temperature during deposition at elevated power and the gas composition during deposition at decreased hydrogen dilution. Based on these investigations, an updated view on the role of the process parameters of plasma power, heater temperature, total gas flow rate, and hydrogen dilution is presented.


TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 20-26 ◽  
Author(s):  
PEEYUSH TRIPATHI ◽  
MARGARET JOYCE ◽  
PAUL D. FLEMING ◽  
MASAHIRO SUGIHARA

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.


2020 ◽  
Author(s):  
Ryan Weber ◽  
Martin McCullagh

<p>pH-switchable, self-assembling materials are of interest in biological imaging and sensing applications. Here we propose that combining the pH-switchability of RXDX (X=Ala, Val, Leu, Ile, Phe) peptides and the optical properties of coumarin creates an ideal candidate for these materials. This suggestion is tested with a thorough set of all-atom molecular dynamics simulations. We first investigate the dependence of pH-switchabiliy on the identity of the hydrophobic residue, X, in the bare (RXDX)<sub>4</sub> systems. Increasing the hydrophobicity stabilizes the fiber which, in turn, reduces the pH-switchabilty of the system. This behavior is found to be somewhat transferable to systems in which a single hydrophobic residue is replaced with a coumarin containing amino acid. In this case, conjugates with X=Ala are found to be unstable and both pHs while conjugates with X=Val, Leu, Ile and Phe are found to form stable β-sheets at least at neutral pH. The (RFDF)<sub>4</sub>-coumarin conjugate is found to have the largest relative entropy value of 0.884 +/- 0.001 between neutral and acidic coumarin ordering distributions. Thus, we posit that coumarin-(RFDF)<sub>4</sub> containing peptide sequences are ideal candidates for pH-sensing bioelectronic materials.</p>


2020 ◽  
Author(s):  
Shubham Deolka ◽  
Orestes Rivada Wheelaghan ◽  
Sandra Aristizábal ◽  
Robert Fayzullin ◽  
Shrinwantu Pal ◽  
...  

We report selective formation of heterobimetallic PtII/CuI complexes that demonstrate how facile bond activation processes can be achieved by altering reactivity of common organoplatinum compounds through their interaction with another metal center. The interaction of the Cu center with Pt center and with a Pt-bound alkyl group increases the stability of PtMe2 towards undesired rollover cyclometalation. The presence of the CuI center also enables facile transmetalation from electron-deficient tetraarylborate [B(ArF)4]- anion and mild C-H bond cleavage of a terminal alkyne, which was not observed in the absence of an electrophilic Cu center. The DFT study indicates that the role of Cu center acts as a binding site for alkyne substrate, while activating its terminal C-H bond.


Author(s):  
Nikolai Petrov ◽  
Nikolai Petrov ◽  
Inna Nikonorova ◽  
Inna Nikonorova ◽  
Vladimir Mashin ◽  
...  

High-speed railway "Moscow-Kazan" by the draft crosses the Volga (Kuibyshev reservoir) in Chuvashia region 500 m below the village of New Kushnikovo. The crossing plot is a right-bank landslide slope with a stepped surface. Its height is 80 m; the slope steepness -15-16o. The authors should assess the risk of landslides and recommend anti-landslide measures to ensure the safety of the future bridge. For this landslide factors have been analyzed, slope stability assessment has been performed and recommendations have been suggested. The role of the following factors have been analyzed: 1) hydrologic - erosion and abrasion reservoir and runoff role; 2) lithologyc (the presence of Urzhum and Northern Dvina horizons of plastically deformable rocks, displacement areas); 3) hydrogeological (the role of perched, ground and interstratal water); 4) geomorphological (presence of the elemental composition of sliding systems and their structure in the relief); 5) exogeodynamic (cycles and stages of landslide systems development, mechanisms and relationship between landslide tiers of different generations and blocks contained in tiers). As a result 6-7 computational models at each of the three engineering-geological sections were made. The stability was evaluated by the method “of the leaning slope”. It is proved that the slope is in a very stable state and requires the following measures: 1) unloading (truncation) of active heads blocks of landslide tiers) and the edge of the plateau, 2) regulation of the surface and groundwater flow, 3) concrete dam, if necessary.


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