scholarly journals Silicone Resin Coating of Micro-Sized Ferrite Particles Using Supercritical Carbon Dioxide

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2012
Author(s):  
Idzumi Okajima ◽  
Tatsuya Kanie ◽  
Takeshi Sako
Keyword(s):  
Film Thickness ◽  
Organic Solvents ◽  
Supercritical Co2 ◽  
Fine Particles ◽  
Particle Diameter ◽  
Coating Material ◽  
Silicone Resin ◽  
Coating Film ◽  
Coating Materials ◽  
Coating Method

An environmentally friendly and efficient polymer coating method for micro-sized particles was developed using supercritical CO2. Because this method used supercritical CO2 as the solvent to dissolve the coating material, we avoided environmental pollution from organic solvents, saved the energy required to evaporate/remove organic solvents, realized a uniform coating film on the fine particles, and prevented agglomeration of the coating particles. The solubilities of the five silicone resins used as coating materials were measured using the flow method, and the data were well correlated by Chrastil’s equation with an average deviation of 5.7%. Resins comprising numerous methyl-group side chains exhibited high solubilities and were suitable coating materials. A new semi-flow-type coating method using supercritical CO2 was also developed, which deposited a film with a uniform thickness of 0.2–1.3 μm on whole fine particles. Notably, in this method, the film thickness was easily controlled. A simple and rapid technique was developed for measuring the coating thickness using X-ray fluorescence analysis. The model for calculating the coating film thickness was based on the material balance of the coating material. This model satisfactorily predicted the thickness with an average error of 0.085 μm by measuring the solubility of the coating material in supercritical CO2, integrated flow volume of supercritical CO2, particle diameter, density and charged weight of the fine particle, and coating material density.

INVESTIGATION OF THE WEAR CHARACTERISTICS OF THERMAL BARRIER COATING IN A BIODIESEL ENGINE

2019 ◽  
Vol 27 (06) ◽  
pp. 1950158
Author(s):  
LEVENT URTEKIN ◽  
SERKAN BAYAŞOĞLU
Keyword(s):  
Combustion Engine ◽  
Fatigue Cracks ◽  
Coating Material ◽  
Engine Oil ◽  
Biodiesel Fuel ◽  
Coating Materials ◽  
Wear Characteristics ◽  
Barrier Coating ◽  
Coating Method ◽  
Thermal Wear

This study applied piston-valve coating for an engine that worked 100% on biodiesel fuel and investigated the wear characteristics after the experiment. The plasma spraying method was used as the coating method. Al2O3 and ZrO2 ceramics, which are the most frequently used ones in the literature, were selected as coating material. The deformations on the coated and uncoated surfaces were determined after running the engine at different time intervals. The deformations on the piston surfaces were interpreted by conducting SEM and EDX analyses. In particular, the deformation on the coating material, thermal fatigue cracks, abrasive wear and elements that clang to the piston surface after combustion were determined. Additionally, post-combustion engine oil analysis was carried out to determine the elements that were released as a result of the thermal wear in connection to combustion. The relationship of the coating with thermal efficiency was investigated for all types of coatings by determining temperatures from a certain point on the engine by using a thermal camera and a surface temperature measurement device. As a result of the SEM, EDX and engine oil (ICP) analyses, it was seen that the elements that are released as a result of wear such as Al, Fe and Cr had lower quantities with the aluminum oxide (Al2O3) coating with the Nickel–Chromium (Ni–Cr) bonding agent in comparison to the other coating materials. Additionally, as a result of oil analyses, the coated engine was observed to have more positive outcomes in comparison to the uncoated engine.

scholarly journals Heat Scanning for the Fabrication of Conductive Fibers

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1405
Author(s):  
Jina Jang ◽  
Haoyu Zhou ◽  
Jungbae Lee ◽  
Hakgae Kim ◽  
Jung Bin In
Keyword(s):  
Silver Nanowires ◽  
Building Blocks ◽  
Dip Coating ◽  
Coating Materials ◽  
Scanning Time ◽  
Silver Ink ◽  
Nylon Fiber ◽  
Coating Method ◽  
Conductive Fibers ◽  
Tubular Heater

Conductive fibers are essential building blocks for implementing various functionalities in a textile platform that is highly conformable to mechanical deformation. In this study, two major techniques were developed to fabricate silver-deposited conductive fibers. First, a droplet-coating method was adopted to coat a nylon fiber with silver nanoparticles (AgNPs) and silver nanowires (AgNWs). While conventional dip coating uses a large ink pool and thus wastes coating materials, droplet-coating uses minimal quantities of silver ink by translating a small ink droplet along the nylon fiber. Secondly, the silver-deposited fiber was annealed by similarly translating a tubular heater along the fiber to induce sintering of the AgNPs and AgNWs. This heat-scanning motion avoids excessive heating and subsequent thermal damage to the nylon fiber. The effects of heat-scanning time and heater power on the fiber conductance were systematically investigated. A conductive fiber with a resistance as low as ~2.8 Ω/cm (0.25 Ω/sq) can be produced. Finally, it was demonstrated that the conductive fibers can be applied in force sensors and flexible interconnectors.

scholarly journals The Effects on Thermal Efficiency of Yttria-Stabilized Zirconia and Lanthanum Zirconate-based Thermal Barrier Coatings on Aluminum Heating Block for 3d Printer

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 792
Author(s):  
Hasan Demir
Keyword(s):  
Temperature Distribution ◽  
Heat Loss ◽  
Yttria Stabilized Zirconia ◽  
Thermal Barrier ◽  
Print Quality ◽  
Stabilized Zirconia ◽  
Coating Materials ◽  
Lanthanum Zirconate ◽  
Barrier Coating ◽  
Coating Method

Fused filament fabrication is an important additive manufacturing method, for which 3D printers are the most commonly used printing tools. In this method, there are many factors that affect the printing quality, chief among which is temperature. The fusion temperature of the material is created by an aluminum heating block in the extruder. Stability and a constant temperature for the aluminum heating block are inevitable requirements for print quality. This study aims to use the thermal barrier coating method to increase the thermal efficiency and stability of the aluminum heating block by reducing heat loss. Furthermore, it aims to perform steady-state thermal analysis using finite element analysis software. The analyses are carried out in stagnant air environment and at the printing temperature of acrylonitrile butadiene styrene material. In order to examine the effects of different coating materials, blocks coated with two different coating materials, as well as uncoated blocks, were used in the analyses. The coating made with yttria-stabilized zirconia and pyrochlore-type lanthanum zirconate materials, together with the NiCRAl bond layer, prevent temperature fluctuation by preventing heat loss. The effects of the coating method on average heat flux density, temperature distribution of blocks, and temperature distribution of the filament tube hole were investigated. Additionally, changes in flow velocity were determined by examining the effects of the thermal barrier coating method on temperature distribution. The average heat flux density in the coated blocks decreased by 10.258%. Throughout the investigation, the temperature distributions in the coated blocks became homogeneous. It was also observed that both coating materials produce the same effect. This article performs a steady-state thermal analysis of a conventional model and thermal-barrier-coated models to increase print quality by reducing heat loss from the aluminum heating block.

scholarly journals The Effect of Film Thickness and Content on Film Formation from PS/ Nanocomposites Prepared by Dip-Coating Method

2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
M. Selin Sunay ◽  
Onder Pekcan ◽  
Saziye Ugur
Keyword(s):  
Film Thickness ◽  
Elevated Temperatures ◽  
Film Formation ◽  
Fluorescence Emission ◽  
Dip Coating ◽  
Atomic Force ◽  
Annealing Step ◽  
Coating Method ◽  
Fluorescence Emission Intensity ◽  
Dip Coating Method

Steady-state fluorescence (SSF) technique in conjunction with UV-visible (UVV) technique and atomic force microscope (AFM) was used for studying film formation from TiO2covered nanosized polystyrene (PS) latex particles (320 nm). The effects of film thickness and TiO2content on the film formation and structure properties of PS/TiO2composites were studied. For this purpose, two different sets of PS films with thicknesses of 5 and 20 μm were prepared from pyrene-(P-) labeled PS particles and covered with various layers of TiO2using dip-coating method. These films were then annealed at elevated temperatures above glass transition temperature () of PS in the range of 100–280°C. Fluorescence emission intensity, from P and transmitted light intensity, were measured after each annealing step to monitor the stages of film formation. The results showed that film formation from PS latexes occurs on the top surface of PS/TiO2composites and thus developed independent of TiO2content for both film sets. But the surface morphology of the films was found to vary with both TiO2content and film thickness. After removal of PS, thin films provide a quite ordered porous structure while thick films showed nonporous structure.

scholarly journals On the Accelerated Settling of Fine Particles in a Bidisperse Slurry

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Leonid L. Minkov ◽  
Yuliya O. Stepanova ◽  
Johann Dueck ◽  
Elizaveta V. Pikushchak
Keyword(s):  
Fine Particles ◽  
Stokes Equations ◽  
Fine Fraction ◽  
Particle Diameter ◽  
Sedimentation Velocity ◽  
Navier Stokes ◽  
Circulation Zone ◽  
Navier Stokes Equations ◽  
Volume Average ◽  
Bidisperse Suspension

An estimation of increasing the volume average sedimentation velocity of fine particles in bidisperse suspension due to their capturing in the circulation zone formed in the laminar flow of incompressible viscous fluid around the spherical coarse particle is proposed. The estimation is important for an explanation of the nonmonotonic shape of the separation curve observed for hydrocyclones. The volume average sedimentation velocity is evaluated on the basis of a cellular model. The characteristic dimensions of the circulation zone are obtained on the basis of a numerical solution of Navier-Stokes equations. Furthermore, these calculations are used for modelling the fast sedimentation of fine particles during their cosedimentation in bidisperse suspension. It was found that the acceleration of sedimentation of fine particles is determined by the concentration of coarse particles in bidisperse suspension, and the sedimentation velocity of fine fraction is proportional to the square of the coarse and fine particle diameter ratio. The limitations of the proposed model are ascertained.

Patterning of fine particles by means of supercritical CO2

2006 ◽  
Vol 41 (5) ◽  
pp. 1605-1610 ◽  
Author(s):  
J. Huang ◽  
T. Moriyoshi ◽  
H. Manabe
Keyword(s):  
Supercritical Co2 ◽  
Fine Particles

scholarly journals Influence of pressure and time on extraction process using supercritical CO2

2008 ◽  
Vol 44 (1) ◽  
pp. 125-131 ◽  
Author(s):  
V. Micic ◽  
Z. Lepojevic ◽  
B. Mandic ◽  
M. Jotanovic ◽  
G. Tadic ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Co2 ◽  
Particle Diameter ◽  
Extraction Process ◽  
Salvia Officinalis ◽  
Quantitative Composition ◽  
Qualitative And Quantitative ◽  
Salvia Officinalis L ◽  
Carbon Dioxide Co2

The supercritical fluid extraction (SFE) by carbon dioxide (CO2) of Salvia officinalis L. was investigated. SFE by CO2 was performed at different pressure (80, 100, 150, 200 and 300 bar) and constant temperature of 40?C (all other extraction conditions, such are flow rate, particle diameter of Salvia officinalis, extraction time were kept constant. The GC-MS method was used for determination of qualitative and quantitative composition of obtained extracts and essential oils.

Study of the System Wood – Coating Material. I. Wood – Liquid Coating Material

Holzforschung ◽  
2000 ◽  
Vol 54 (2) ◽  
pp. 189-196 ◽  
Author(s):  
Eva Liptáková ◽  
Jozef Kúdela ◽  
Ján Sarva
Keyword(s):  
Phase Boundary ◽  
Rheological Properties ◽  
Wood Surface ◽  
Surface Forces ◽  
Coating Material ◽  
Actual State ◽  
Wood Coating ◽  
Coating Materials ◽  
Wetting Process ◽  
Adhesion Work

Summary This paper deals with the evaluation of wood—wetting process with coating materials on the basis of interactions of surface forces on phase boundary. The obtained results are compared with the actual state in the system wood—coating material. Primary ability of coating materials—spontaneous spreading over the wood surface has been proved. There is also the secondary influence of rheological properties of coating materials causing deformations of the phase boundary, non-perfect wetting of the wood surface and apparent lowering of adhesion work. The influence of rheological properties has been expressed by using the coefficient F the meaning of which follows from the comparison between results of adhesion work computed according to modified Young-Dupré equation and of adhesion work determined on the basis of the interactions of surface forces on the phase boundary between wood and liquid coating materials. A direct dependence between the values of the coefficient F and coating materials viscosity has been proved.

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