scholarly journals The Influence of Different Pre-Treatments of Concrete Surface on the Bond Strength of Geopolymer-Type Coating Layer

2018 ◽  
Vol 10 (11) ◽  
pp. 4053 ◽  
Author(s):  
Alena Sicakova

The treatment of concrete surface using more durable material is one way to slow down the damage process of material, which can negatively affect durability of construction. This paper is aimed at testing the geopolymer-type coating materials of different composition while placing emphasis on various techniques of surface pre-treatments of concrete to which they were applied. The main composition variables were as follows: the fly ash fineness (original, ground) and the addition of washing-aggregate sludge. Four compositions were tested and compared with the composition based on cement binder. The cement mixture was prepared using the same fillers. The following techniques of surface pre-treatment of concrete were applied: brushing, pressure washing, and pressure washing followed by penetration, together with non-treated surface being used for comparison. The effect of the surface treatment technique was tested through the adhesion strength, which was executed at 2, 7, 28, and 120 days after application of the coating. The influence of the composition of geopolymer coating material was also discussed. Geopolymer-based mixtures achieved better adhesive strength than the cement-based mixture, regardless of surface treatment technique. The addition of sludge microfiller seems to be beneficial in improving the adhesive strength of geopolymer-type coating material.

2021 ◽  
Author(s):  
Ronald Joseph Turner ◽  
Pieter Bots ◽  
Alan Richardson ◽  
Paul Bingham ◽  
Alex Scrimshire ◽  
...  

(Hydroxy)apatite [Ca10(PO4)6(OH)2], has emerging potential as a cement coating material, with applications in environmental remediation, nuclear waste storage and architectural preservation. In these low temperature environments and when precipitating from...


2019 ◽  
Vol 109 (11-12) ◽  
pp. 857-861
Author(s):  
E. Uhlmann ◽  
E. Bath ◽  
J. Gäbler ◽  
M. Höfer

Der Cobalt-(Co)-Anteil in Hartmetallen diffundiert während des Diamantbeschichtungsprozesses in die Diamantschicht und mindert deren Haftfähigkeit. Siliciumcarbid-(SiC)-Zwischenschichten können als Diffusionsbarriere für Cobalt dienen und die konventionelle Ätzvorbehandlung der Substrate ersetzen. Im Rahmen einer Forschungsarbeit werden Beschichtungsprozesse mit SiC-Zwischenschicht entwickelt, diese Schichtsysteme auf verschiedene Substrate aufgebracht und durch Zerspanungsuntersuchungen bewertet.   The cobalt (Co) content in cemented carbide tools diffuses into the diamond layer during the coating process and reduces its adhesive strength. Siliciumcarbid-(SiC)-interlayers can serve as a diffusion barrier for cobalt and replace the conventional etching pre-treatment of blanks. In a research project different coating processes with SiC-interlayer are developed, the coating systems are applied to different substrates and evaluated in cutting experiments.


Author(s):  
R. Subasri

Surface cleaning and activation of substrates are two critical processes that affect the mechanical and corrosion resistance properties of protective coatings when deposited on the substrates. Surface cleaning removes the contaminants, for example, grease on the substrate, and surface activation introduces active bonds on the substrate thereby increasing the surface free energy. Conventionally, surface cleaning and activation of aluminum and its alloys are carried out by a wet chemical technique. A convenient and safe alternate to the wet chemical cleaning/activation would be to use plasma for the same purpose. Plasma surface pre-treatment greatly improves adhesion of coatings deposited, which is very vital for good corrosion protection and mechanical properties such as scratch and abrasion resistance. Cold and atmospheric air plasma treatments have been the most widely studied pre-treatments for Al alloys. This article will discuss the advancements in the use of plasma treatment on Al/Al alloys and its effect on corrosion resistance and mechanical properties of coatings deposited after the surface treatment.


2017 ◽  
Vol 29 ◽  
pp. 407-418 ◽  
Author(s):  
A. Jacob ◽  
S. Gangopadhyay ◽  
A. Satapathy ◽  
S. Mantry ◽  
B.B. Jha

2002 ◽  
Vol 122 (2) ◽  
pp. 73-77 ◽  
Author(s):  
Takeshi Harada ◽  
Yasuhiro Yoshimura ◽  
Akiomi Kouno

Holzforschung ◽  
2000 ◽  
Vol 54 (2) ◽  
pp. 189-196 ◽  
Author(s):  
Eva Liptáková ◽  
Jozef Kúdela ◽  
Ján Sarva

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.


2018 ◽  
Vol 25 (35) ◽  
pp. 4553-4586 ◽  
Author(s):  
Jonas Schubert ◽  
Munish Chanana

Within the last two decades, the field of nanomedicine has not developed as successfully as has widely been hoped for. The main reason for this is the immense complexity of the biological systems, including the physico-chemical properties of the biological fluids as well as the biochemistry and the physiology of living systems. The nanoparticles’ physicochemical properties are also highly important. These differ profoundly from those of freshly synthesized particles when applied in biological/living systems as recent research in this field reveals. The physico-chemical properties of nanoparticles are predefined by their structural and functional design (core and coating material) and are highly affected by their interaction with the environment (temperature, pH, salt, proteins, cells). Since the coating material is the first part of the particle to come in contact with the environment, it does not only provide biocompatibility, but also defines the behavior (e.g. colloidal stability) and the fate (degradation, excretion, accumulation) of nanoparticles in the living systems. Hence, the coating matters, particularly for a nanoparticle system for biomedical applications, which has to fulfill its task in the complex environment of biological fluids, cells and organisms. In this review, we evaluate the performance of different coating materials for nanoparticles concerning their ability to provide colloidal stability in biological media and living systems.


2008 ◽  
Vol 1139 ◽  
Author(s):  
Seisuke Kano ◽  
Sohei Matsumoto ◽  
Naoki Ichikawa

AbstractHydrophobic property of PDMS surface was improved by the 400 W UV-Vis lamp light irradiation in the atmospheric condition for several ten minutes. As a result of this surface treatment, the surface became to hydrophilic character for one month long. This surface treatment technique applied to PDMS micro-fluidic device and verified valve-less switching. The UV-Vis light irradiated to PDMS micro fluidic pattern with partly covered by aluminum foil. Finally inlet and outlets were connected 0.5 mm diameter tubes. The syringe pumps injected the distilled water into the inlet of the PDMS micro channel at the flow rates of 0.5, 5.0, and 50 μl/min for the both width channel. As results of water injection water flowed only the UV-Vis treated channel at the flow rates of 0.5 and 5.0 μl/min. On the other hand, the water flowed for all channels at the flow rate of 50 μl/min. This result was observed from 5.0 μl/min flow again for both width devices which dried by air. These results were occurred by the difference of the flow conductance and wettability. The mechanism of this hyrophilicity of PDMS was reported to form Si-O in the surface by means of glassy surface. From the IR spectra, the Si-O-Si peak shifted to higher wave number for UV-Vis irradiated PDMS than the untreated PDMS comparing with the other IR peaks. This result showed that the Si-O-Si network bonding of PDMS changed to the O-Si-O bonding around the surface.


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