Effect of Aluminum Substrate Surface Modification on Wettability and Freezing Delay of Water Droplet at Subzero Temperatures

2016 ◽  
Vol 8 (17) ◽  
pp. 11147-11153 ◽  
Author(s):  
Maral Rahimi ◽  
Alireza Afshari ◽  
Esben Thormann
Keyword(s):  
Surface Modification ◽  
Water Droplet ◽  
Substrate Surface ◽  
Aluminum Substrate ◽  
Subzero Temperatures

scholarly journals Assessment of Titanate Nanolayers in Terms of Their Physicochemical and Biological Properties

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 806
Author(s):  
Michalina Ehlert ◽  
Aleksandra Radtke ◽  
Katarzyna Roszek ◽  
Tomasz Jędrzejewski ◽  
Piotr Piszczek
Keyword(s):  
Surface Modification ◽  
Substrate Surface ◽  
Biological Properties ◽  
Structure Characterization ◽  
Porous Coating ◽  
Apatite Formation ◽  
Sem Images ◽  
Energy Dispersion Spectroscopy ◽  
X Ray

The surface modification of titanium substrates and its alloys in order to improve their osseointegration properties is one of widely studied issues related to the design and production of modern orthopedic and dental implants. In this paper, we discuss the results concerning Ti6Al4V substrate surface modification by (a) alkaline treatment with a 7 M NaOH solution, and (b) production of a porous coating (anodic oxidation with the use of potential U = 5 V) and then treating its surface in the abovementioned alkaline solution. We compared the apatite-forming ability of unmodified and surface-modified titanium alloy in simulated body fluid (SBF) for 1–4 weeks. Analysis of the X-ray diffraction patterns of synthesized coatings allowed their structure characterization before and after immersing in SBF. The obtained nanolayers were studied using Raman spectroscopy, diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), and scanning electron microscopy (SEM) images. Elemental analysis was carried out using X-ray energy dispersion spectroscopy (SEM EDX). Wettability and biointegration activity (on the basis of the degree of integration of MG-63 osteoblast-like cells, L929 fibroblasts, and adipose-derived mesenchymal stem cells cultured in vitro on the sample surface) were also evaluated. The obtained results proved that the surfaces of Ti6Al4V and Ti6Al4V covered by TiO2 nanoporous coatings, which were modified by titanate layers, promote apatite formation in the environment of body fluids and possess optimal biointegration properties for fibroblasts and osteoblasts.

Biocompatible Ceramic-Biopolymer Coatings Obtained by Electrophoretic Deposition on Electron Beam Structured Titanium Alloy Surfaces

2016 ◽  
Vol 879 ◽  
pp. 1552-1557
Author(s):  
C. Ramskogler ◽  
L. Cordero ◽  
Fernando Warchomicka ◽  
A.R. Boccaccini ◽  
Christof Sommitsch
Keyword(s):  
Titanium Alloy ◽  
Surface Modification ◽  
Electron Beam ◽  
Electrophoretic Deposition ◽  
Composite Coatings ◽  
Substrate Surface ◽  
3D Structure ◽  
Titania Nanoparticles ◽  
Structured Surfaces ◽  
Major Interest

An area of major interest in biomedical engineering is currently the development of improved materials for medical implants. Research efforts are being focused on the investigation of surface modification methods for metallic prostheses due to the fundamental bioinert character of these materials and the possible ion release from their surfaces, which could potentially induce the interfacial loosening of devices after implantation. Electron beam (EB) structuring is a novel technique to control the surface topography in metals. Electrophoretic deposition (EPD) offers the feasibility to deposit at room temperature a variety of materials on conductive substrates from colloidal suspensions under electric fields. In this work single layers of chitosan composite coatings containing titania nanoparticles (n-TiO2) were deposit by EPD on electron beam (EB) structured Ti6Al4V titanium alloy. Surface structures were designed following different criteria in order to develop specific topography on the Ti6Al4V substrate. n-TiO2 particles were used as a model particle in order to demonstrate the versatility of the proposed technique for achieving homogenous chitosan based coatings on structured surfaces. A linear relation between EPD time and deposition yield on different patterned Ti6Al4V surfaces was determined under constant voltage conditions, obtaining homogeneous EPD coatings which replicate the 3D structure (pattern) of the substrate surface. The present results show that a combination of both techniques can be considered a promising surface modification approach for metallic implants, which should lead to improved interaction between the implant surface and the biological environment for orthopaedic applications.

scholarly journals Surface modification as a technique to improve inter-layer bonding strength in 3D printed cementitious materials

2019 ◽  
Vol 4 ◽  
pp. 33-38 ◽  
Author(s):  
Jolien Van Der Putten ◽  
Geert De Schutter ◽  
Kim Van Tittelboom
Keyword(s):  
Surface Roughness ◽  
Surface Modification ◽  
Bonding Strength ◽  
Substrate Surface ◽  
Cementitious Materials ◽  
Degree Of Hydration ◽  
Custom Made ◽  
Wire Brushing ◽  
Modification Technique ◽  
3D Printed

The structural capacity of 3D printed components mainly depends on the inter-layer bonding strength between the different layers. This bond strength is affected by many parameters (e.g. moisture content of the substrate, time gap, surface roughness,..) and any mismatch in properties of the cementitious material may lead to early failure. A common technique to improve inter-layer bonding strength between a substrate and a newly added layer is modifying the substrate surface. For the purpose of this research, a custom-made 3D printing apparatus is used to simulate the printing process and layered specimens with a different delay time (0 and 30 minutes) are manufactured with different surface modification techniques (wire brushing, addition of sand or cement and moisturizing substrate layer). The surface roughness was measured and the effect of the modification technique on the inter-layer-bonding strength was investigated. Results showed that the most effective way to increase the inter-layer bonding is increasing the surface roughness by a comb. This creates a kind of interlock system that will provide a higher inter-layer strength. The compressive strength is most influenced by the addition of cement, where the changing W/C-ratio will create a higher degree of hydration and consequently a higher strength.

scholarly journals Droplet Impact in Icing Conditions – Experimental Study for WE 540

2017 ◽  
Vol 64 (2) ◽  
pp. 165-175
Author(s):  
Tomasz Lizer ◽  
Michał Remer ◽  
Grzegorz Sobieraj ◽  
Maciej Psarski ◽  
Daniel Pawlak ◽  
...  
Keyword(s):  
Experimental Study ◽  
Water Droplet ◽  
Surface Coating ◽  
Room Temperature ◽  
Droplet Impact ◽  
Droplet Impingement ◽  
Wetting Properties ◽  
Subzero Temperatures ◽  
Thermographic Camera ◽  
Two Temperatures

Abstract The work presents investigation on the water droplet impingement at a substrate with three different surface coating. The experiments are carried out for two temperatures of the surface: 23°C (room temperature) and −10°C. The water droplet contact is recorded via ultra-fast camera and simultaneously via fast thermographic camera. The wetting properties are changing for subzero temperatures of substrates.

Substrate Surface Modification for Enlarging Two-Dimensional SnS Grains at Low Temperatures

2020 ◽  
Vol 32 (20) ◽  
pp. 9026-9033
Author(s):  
In-Hwan Baek ◽  
Ah-Jin Cho ◽  
Sangtae Kim ◽  
Ga Yeon Lee ◽  
Jeong Hwan Han ◽  
...  
Keyword(s):  
Surface Modification ◽  
Low Temperatures ◽  
Substrate Surface ◽  
Two Dimensional

Surface Modification of Polytetrafluoroethylene and the Deposition of Copper Films

1993 ◽  
Vol 304 ◽  
Author(s):  
Wenbiao Jiang ◽  
M. Grant Norton ◽  
J. Thomas Dickinson
Keyword(s):  
Surface Modification ◽  
Surface Morphology ◽  
Chemical Modification ◽  
Excimer Laser ◽  
Substrate Surface ◽  
Polymer Surface ◽  
Metal Deposition ◽  
Copper Films ◽  
Charged Species ◽  
Significant Chemical

AbstractEnhancement of the adhesion of thin copper films on polytetrafluoroethylene substrates was found when the substrate surface was irradiated with a pulsed UV excimer laser prior to metal deposition. The interaction between the laser and the polymer was examined by characterizing the neutral and charged species emitted from the surface during irradiation. The nature of the species emitted indicates that significant chemical modification of the polymer surface occurs. In addition to chemical modification, the interaction with the laser also alters the surface morphology of the polymer. Irradiation at fluences of ∼ 0.6 J/cm2 results in an overall planarization of the surface, whilst irradiation at higher fluences results in the formation and enlargement of voids and localized melting.

scholarly journals Nanoscale Effects in Temperature Induced Polymer Coatings

2009 ◽  
Vol 3 (3) ◽  
pp. 209-212
Author(s):  
Nikolay Bulychev ◽  
◽  
Frederik Wurst ◽  
Viktor Fomin ◽  
Thadeus Schauer ◽  
...  
Keyword(s):  
Surface Modification ◽  
Surface Morphology ◽  
Lower Critical Solution Temperature ◽  
Polymer Coating ◽  
Polymer Solutions ◽  
Substrate Surface ◽  
Polymer Coatings ◽  
Solution Temperature ◽  
Critical Solution Temperature ◽  
Polymer Deposition

In this paper the results of recent studies on the application of lower critical solution temperature (LCST) phenomena of polymer solutions to the surface modification of flat and spherical substrates are reported. It has been found that controlled polymer deposition can be achieved at temperatures exceeding LCST. The obtained polymer coating exhibits a peculiar surface morphology and, if particles are introduced, can be highly effective in pigment dispersions stabilizing. It has been established that the temperature induced polymer deposition can be carried out as the finely dispersed component precipitation on the substrate surface that goes along with the polymer deposition at temperatures exceeding LCST, which in its turn allows to modify the pigments surface when finely dispersed additives are incorporated into the surface modifying coating.

scholarly journals Influence of the Mg and Bi content on brazeability of MONOBRAZE material under flux-free brazing conditions

2020 ◽  
Vol 326 ◽  
pp. 08003
Author(s):  
Kanokploy Phumprasop ◽  
Dai Yamamoto ◽  
Noriyuki Yamada ◽  
Hirokazu Tanaka
Keyword(s):  
Oxide Film ◽  
Fine Particles ◽  
Substrate Surface ◽  
Single Layer ◽  
Aluminum Substrate ◽  
Filler Layer

In the conventional brazing, the clad materials with the filler layer and the flux coating have been used to get good brazeability. However, an innovative Al-Si based single-layer brazing material (MONOBRAZE® material) has been developed recently which does not need filler layer by supplying molten filler from the inside of the material during brazing. In addition, a new flux-free brazing technique has also been developed. In the flux-free brazing, Mg and Bi are added to break the oxide film and to improve the wettability of molten filler, respectively. However, it is not clarified how these element works on the brazeability of MONOBRAZE® material in flux-free brazing. Therefore, in this study the effect of Mg and Bi content on the brazeability of MONOBRAZE® material was investigated. From the result, it is found that MONOBRAZE® material is applicable for flux-free brazing by adding Mg. Mg is considered to break the oxide film into fine particles and Bi is considered to assist the destruction of oxide film. From this cause, a new aluminum substrate surface was exposed which allow molten filler to move on the surface and contribute to the formation of the fillet.

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