Influence Of Intermediate Layer Research Articles

Design and Strengthening of Superhydrophobic Coatings: The Influence of Intermediate Layers

The employment of intermediate layer technology to improve the mechanical stability of superhydrophobic coatings (SHCs) is an acknowledged tool, but the mechanism by which intermediate layers, especially different ones, affect superhydrophobic composite coatings is not clear. In this work, a series of SHCs based on the strengthening of the intermediate layer were fabricated by employing polymers with different elastic moduli such as polydimethylsiloxane (PDMS), polyurethane (PU), epoxy (EP) resin, as well as graphite/SiO2 hydrophobic components. Following that, the effect of different elastic modulus polymers as an intermediate layer on the durability of SHCs was investigated. From the perspective of elastic buffering, the strengthening mechanism of elastic polymer-based SHCs was clarified. Furthermore, from the perspective of self-lubrication, the wear resistance mechanism of self-lubricating hydrophobic components in the SHCs was elucidated. Also, the prepared coatings exhibited excellent acid and alkali resistance, self-cleaning, anti-stain, and corrosion resistance. This work confirms that low-elastic-modulus polymers can also play the role of buffering external impact energy by elastic deformation even as an intermediate layer, and provides theoretical guidance for the development of SHCs with robustness.

The influence of intermediate layer and graphene oxide modification on the CO2 capture efficiency of Pebax-GO/PDMS/PSf mixed matrix composite membranes

Background: Greenhouse gasses are still a global concern where minimization of or controlling its emission should be prioritized. This could be efficiently resolved through membrane separation technology.Methods: Herein, a mixed matrix composite membrane made from poly(dimethylsiloxane) (PDMS), Pebax® MH1657 (Pebax), and 3-(Aminopropyl)triethoxysilane (APTES)-modified graphene oxide on a polysulfone (PSf) substrate was prepared. The hydrophilicity of PDMS intermediate layer was improved by UV/O3 treatment. While the concentrations of Pebax and APTES-GO loading were varied to observe the combined effects of active and intermediate layers on CO2 capture.Significant findings: The membrane with 1 wt% GO loading had the optimal gas separation performance with a CO2 permeability of 54.5 GPU and a CO2/N2 selectivity of 36.9 at 35 °C and 0.1 MPa. The separation was further improved with APTES-functionalized GO (aGO). The mixed matrix composite membrane with 1 wt% aGO loading augmented the CO2 permeance to 208.9 GPU with a CO2/N2 selectivity of 40 at 35 °C and 0.7 MPa. The amine groups augmented the CO2 adsorption and selectivity and provided enhanced membrane stability that can also be operated at higher pressure. This study provides an understanding on the function of each layer on a gas separation mixed matrix composite membrane.

Influence of intermediate layer on the strength of freezing of soil with the metal surface of machines at negative temperatures

The development of moist cohesive soils in conditions of negative temperatures leads to a decrease in the productivity of earth-moving machines due to the increase in adhesion and friction. When wet soil and a metal bucket interact, the soil freezes to the sides of the bucket, which leads to a decrease in the useful volume of the bucket and, therefore, to a decrease in the productivity of the machine. The experimental studies have been carried out on the effect of the intermediate layer at the interface between the soil and the working body of the machine, on adhesion. The prophylactic lubricant "Niogrin" was used as an intermediate layer. As a result of processing the obtained experimental data, a regression equation was obtained; the dependence of the soil shear stress on various factors is presented and the influence of external factors on the adhesion of soils at negative temperatures is estimated. The comparison of the obtained dependencies showed that the strength of soil freezing when using a preventive liquid decreases 1.5-2 times.

Quantitative strain measurement and crack opening estimate in concrete structures based on OFDR technology

Abstract Concrete structures are easy to produce cracks which seriously affect the safety of the structures. Rayleigh based distributed optical fiber sensing technique has been used to measure the strain field evolution associated with crack initiation and growth in concrete structures. A reinforced concrete beam has been tested under four-point loading test with optical fibers both pasted on the surface and embedded as the distributed sensors. Experimental results indicate that cracks can be detected at sharp peaks of the measured strain distributions, which can be utilized to effectively capture the number of cracks and locate multiple cracks. The abilities of using optical frequency domain reflectometry (OFDR) technology to detect hairline cracks and distinguish neighboring cracks are also discussed. Single crack opening displacement is determined through fitting process which taken the influence of intermediate layers into consideration, the widening and propagation of cracks in the overall concrete beam were detected.

Formation of NaY zeolite membrane: influence of intermediate layer and its characterization

In the synthesis process of zeolite membranes, the zeolites crystals are crystallized and grow during crystallization period to form polycrystalline film.Secondary growth method is an effective method to synthesis high quality zeolite membranes which involves two main steps which are coating and hydrothermal treatment (HT) synthesis. There are several problems associated with the coating process in secondary growth method such as lack of good adherence of the seeds, rough surface of the support, and thermal mismatch between the zeolite seeds and supports during hydrothermal process. In order to solve these issues, an intermediate layer (buffer layer) could be applied between the support and the seeds layer hence to reduce the defects forms during the hydrothermal treatment (HT) synthesis process. In current study, two different types of intermediate layer were studied and results were compared in terms of zeolite seeds coverage on the surface of the support and zeolite layer formed during subsequent hydrothermal treatment (HT) to form zeolite membranes. The formed zeolite membranes were characterized with X-Ray diffraction (XRD) and scanning electron microscopy (SEM) and energy dispersive X-Ray spectroscopy (EDX).

Influence of intermediate layers in tubular carbon membrane for gas separation performance

The main objective of this study is to determine the best intermediate layer for tubular carbon membranes for H2 and He separation. Intermediate layer was applied to strengthen interfacial adhesion between selective carbon layers and tubular support. Three different intermediate layers (alumina powder, carbon molecular sieve (CMS), and carbon pencil) had been evaluated to compare their influence towards the performance of gas separation of the carbon membrane. Tubular carbon membrane was fabricated from PI/NCC-based polymer blends which had been carbonized under Argon atmosphere at 800 °C with a heating rate of 3 °C/min. Based on the scanning electron microscopic (SEM) observations, carbon membrane with alumina powder as an intermediate layer had formed a smoother surface compared to other types of intermediate layers. A high performance of tubular carbon membrane was obtained by employing alumina powder as an intermediate layer, which exhibited the best selectivity of H2/N2 and He/N2 of 447.31 ± 1.45 and 471.72 ± 2.19, respectively.

Modeling the influence of the coating deposition technology on the contact interaction characteristics

For a multilayer elastic half-space, we consider an axisymmetric loading model taking into account damage on the interface between the layers. The influence of intermediate layers arising in various coating technologies on the contact and internal stresses occurring in the coating and the substrate under elastic indentation conditions is studied for relatively rigid and nonrigid coatings.

Influence of intermediate layers on the surface condition of laser crystallized silicon thin films and solar cell performance

The intermediate layer (IL) between glass substrate and silicon plays a significant role in the optimization of multicrystalline liquid phase crystallized silicon thin film solar cells on glass. This study deals with the influence of the IL on the surface condition and the required chemical surface treatment of the crystallized silicon (mc-Si), which is of particular interest for a-Si:H heterojunction thin film solar cells. Two types of IL were investigated: sputtered silicon nitride (SiN) and a layer stack consisting of silicon nitride and silicon oxide (SiN/SiO). X-ray photoelectron spectroscopy measurements revealed the formation of silicon oxynitride (SiOxNy) or silicon oxide (SiO2) layers at the surface of the mc-Si after liquid phase crystallization on SiN or SiN/SiO, respectively. We propose that SiOxNy formation is governed by dissolving nitrogen from the SiN layer in the silicon melt, which segregates at the crystallization front during crystallization. This process is successfully hindered, when additional SiO layers are introduced into the IL. In order to achieve solar cell open circuit voltages above 500 mV, a removal of the formed SiOxNy top layer is required using sophisticated cleaning of the crystallized silicon prior to a-Si:H deposition. However, solar cells crystallized on SiN/SiO yield high open circuit voltage even when a simple wet chemical surface treatment is applied. The implementation of SiN/SiO intermediate layers facilitates the production of mesa type solar cells with open circuit voltages above 600 mV and a power conversion efficiency of 10%.

Influence of intermediate layer on transmission characteristics of W-type optical fibers

Abstract Transmission characteristics of multimode W-type optical fibers (doubly clad fibers with three layers) are investigated by solving the time-dependent power flow equation. A numerical solution has been obtained by the explicit finite difference method. Results show how the bandwidth in W-type optical fibers varies with depth and width of the intermediate layer for different coupling strengths and excitations. The trade-off between the bandwidth and steady-state loss is also specified. Such characterization of these fibers is consistent with their manifested effectiveness in reducing modal dispersion and bending loss.

Influence of intermediate layer on the formation of intermetallic compound layer in joining aluminum alloy ― cast iron

Influence of intermediate layer on the formation of intermetallic compound layer in joining aluminum alloy ― cast iron

Influence of Deposition Rate and Intermediate Layer on Crystal Structure of Pb(Zr,Ti)O 3 Thin Films Prepared by RF Sputtering

Pb(Zr,Ti)O 3 (PZT) thin films were prepared by rf magnetron sputtering. To obtain perovskite phase at low substrate temperature, the influence of intermediate layers on crystallization were investigated. Mixed phases of perovskite and pyrochlore PZT were obtained on PbTiO 3 intermediate layer at substrate temperature of 610°C. On the contrary, perovskite phase PZT was obtained without post deposition thermal annealing on amorphous PZT intermediate layer at substrate temperature and deposition rate of 610°C and 6 nm/min, respectively. In PZT (except the surface region) and in amorphous PZT intermediate layer, chemical composition of auger depth profile was uniform.

Influence of intermediate layers and base materials on adhesion of amorphous carbon and metal-carbon coatings

Metal carbon (Me : C) and hydrogen-containing amorphous carbon (a-C : H) layers offer interesting possibilities for coating of tools because of their remarkable tribological features. But normally adhesion to steels used as base materials for tools is very low. A hybrid physical vapour deposition (PVD)-plasma chemical vapour deposition (PCVD) process was used to deposit zirconium (Zr)/intermediate layer/Zr : C. The a-C : H layers were deposited in a parallel plate reactor by PCVD with RF plasma. The graded Zr : C coating adheres well to various steels, very low adhesion is observed to a cobalt-containing steel and to cobalt-based hard metals. a-C : H adheres very well to silicon, glass, and aluminium (Al), but delamination in the bulk of the base material can occur due to high compressive stress. Adhesion to steel can be improved by thin layers of Al and tungsten (W), but different mechanisms seem to be the reasons for the improvement. The adhesion to hard metals increases with increasing WC content.

Influence of intermediate layers on coercive force of laminated Co-P films

This paper investigated the coercive force (H c ) of laminated Co-P films. The films were laminated by introducing intermediate layers of Pd ( T \sim 25 A) or nonmagnetic Ni-P (T = 250 A) between the Co-P films. The thickness of the Co-P films was varied from 650 A to 2600 A but was maintained constant within any series of laminations. The H c was evaluated as a function of total thickness for multiple Co-P laminate thicknesses up to 10,000 A. The H c of laminated Co-P films with intermediate Pd layers increased with total lamination thickness regardless of the thickness of the individual Co-P film. However, Co-P laminates deposited from a dilute solution with intermediate layers of Ni-P exhibited H c values independent of the total lamination thickness. The H c was independent of the total lamination thickness regardless of the base material provided Ni-P was deposited as the substrate. The magnitude of the H c was dependent on the Co-P film thickness. The H c of such Co-P laminates can be adjusted from 340 Oe to 700 Oe by selection of the appropriate thickness of the Co-P film. Co-P laminates deposited from a concentrated solution with intermediate layers of Ni-P exhibit H c values which decrease with total lamination thickness. These films exhibited lower H c values than nonlaminated Co-P films.

Influence of intermediate layers on the magnetic properties of thin electrolytically prepared Co-P films

Influence of intermediate layers on the magnetic properties of thin electrolytically prepared Co-P films