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1 – 8 of 8This paper aims to achieve an anti-corrosive coating via uniform dispersion of nanoclay particles (montmorillonite) and polypyrrole (PPy) as a conductive polymer as well as their…
Abstract
Purpose
This paper aims to achieve an anti-corrosive coating via uniform dispersion of nanoclay particles (montmorillonite) and polypyrrole (PPy) as a conductive polymer as well as their effects on the anti-corrosion features in the presence of the eco-friendly ionic liquids (ILs).
Design/methodology/approach
In this research, PPy with different forms of nanoclay were used. Moreover, ILs additive is used to enhance the better dispersion process of clay and PPy nanoparticles in the resin.
Findings
As a result, the IL additive in the formulation of nano-composite coatings greatly improves the dispersion process of clay and PPy nanoparticles in the resin. Due to its high compatibility with polyurethane resin and clay and PPy nanoparticles, this additive contains a high dispersing power to disperse the investigated nanoparticles in the resin matrix.
Research limitations/implications
High polarity of ILs as well as abilities to dissolve both mineral and organic materials, they can provide the better chemical processes compared to common solvents.
Practical implications
IL abilities have not been discovered to a large extent such as catalysts and detectors.
Social implications
ILs have been emerging as promising green solvents to replace conventional solvents in recent years. They possess unique properties such as nonvolatility, low toxicity, ease of handling, nonflammability and high ionic conductivity. Thus, they have received much attention as green media for various chemistry processes.
Originality/value
The simultaneous existence of clay, PPy and IL additive in the nano-composite coating formulation is responsible for the high corrosion resistance of the coating.
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The purpose of this work was to study the effect of different wood surface preparations on the wetting and adhesion of coating.
Abstract
Purpose
The purpose of this work was to study the effect of different wood surface preparations on the wetting and adhesion of coating.
Design/methodology/approach
In this research, six different chemical preparations to evaluate the photostability and properties of wood coating. Also, the effect of the same wood treatments on the properties of the coating, i.e. wetting, adhesion and the permeability of two types of coatings, was investigated.
Findings
As a result, benzoyl chloride and chromic acid were found to be the most effective photostabilizing preparations. Solvent-based polyurethane was more compatible with the prepared wood surfaces compared with water-based alkyd coatings.
Research limitations/implications
Chemical modifications of wood surfaces affected the wetting of various coatings.
Practical implications
Various surface properties could be changed using preparation that affects important coating properties.
Social implications
Unfortunately, the properties of transparent wood coatings used outdoors disappear through the early years of use, essentially due to the wood substrate’s photodegradation.
Originality/value
Wood is a widespread substrate because of its comfortable handling, availability, proper cost of preparation and its good mechanical strength because of its density. Architects and designers tend to use wood in the construction of green buildings. However, this material is disposed to weathering while using outdoors and it should be solved.
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The purpose of this paper is to study the correlation between different topographies and the reaction of Ulva Linza fouling species.
Abstract
Purpose
The purpose of this paper is to study the correlation between different topographies and the reaction of Ulva Linza fouling species.
Design/methodology/approach
In this research, topographies with a different method, such as hot embossing and hot pulling, were achieved, and biological analyses were done with macroalgae Ulva Linza cells. The effect of topography via local binding geometry (honeycomb size gradients) and Wenzel roughness on the settling of Ulva microorganisms was tested.
Findings
As a result, Ulva spores confirmed different reactions to a similar set of tapered microstructures that was in agreement with the results on distinct honeycombs. The local binding geometry and the Wenzel roughness factor “r” were dominant on settling of Ulva Linza spores.
Research limitations/implications
The reaction of an organism at the interface of vehicles’ substrate is powerfully affected by surface topographies.
Practical implications
The best embedment occurred on structures with bigger sizes than Ulva Linza’s spores. The density of settled spores was proportional to Wenzel roughness and the spores favour to attach to “kink sites” positions.
Social implications
Unfortunately, unpleasant aggregation of marine biofouling on marine vehicles’ surfaces, generate terrific difficulties in the relevant industry.
Originality/value
There was a sharp relationship between Wenzel roughness and settle of Ulva Linza spores. The local binding geometry and the Wenzel roughness factor “r” were dominant on settling of Ulva Linza spores.
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The purpose of this study is to evaluate the possibility of using titanium dioxide coating in the field of architectural heritage.
Abstract
Purpose
The purpose of this study is to evaluate the possibility of using titanium dioxide coating in the field of architectural heritage.
Design/methodology/approach
In this research, a titanium dioxide coating was prepared and then applied to the travertine stone surfaces. The nature of the coating was determined through various observations and analyses. Moreover, the effect of photocatalytic self-cleaning was evaluated using an organic dye (Rhodamine B).
Findings
The results of XRD, DLS and SEM confirmed the formation of small anatase crystals. The hydrophilic behavior on the surface was observed by coatings based on titanium dioxide.
Research limitations/implications
The self-cleaning ability of titanium dioxide is due to the synergistic effect of its optical inductive property, which is activated with sunlight.
Practical implications
The self-cleaning coatings are interested for many industries. The reported data can be used by the formulators working in the research and development departments.
Social implications
Self-cleaning systems are considered as smart coatings. Therefore, the developing of its knowledge can help to extend its usage to different applications.
Originality/value
The application of titanium dioxide coating in the field of architectural heritage is a great challenge. Therefore, in this research, a titanium dioxide coating was prepared by sol-gel method and then applied on travertine surfaces and its properties were studied.
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Amir Samadi, Reza Amini, Mehran Rostami, Pooneh Kardar and Michele Fedel
The purpose of this study was to evaluate the possibility of using conductive polymers such as polyaniline (PANI) as corrosion inhibitors for metals.
Abstract
Purpose
The purpose of this study was to evaluate the possibility of using conductive polymers such as polyaniline (PANI) as corrosion inhibitors for metals.
Design/methodology/approach
In this study, the effect of the addition of praseodymium (Pr3+) cations on the corrosion inhibition performance of PANI for AZ31 magnesium alloy was appraised through electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization tests.
Findings
The results of EIS and potentiodynamic polarization tests indicated the improvement of corrosion resistance of AZ31 during different immersion times.
Research limitations/implications
This anti-corrosion ability of PANI/Pr3+ composite applies as non-toxic environmentally friendly corrosion inhibitor on the self-healing corrosion protection properties.
Practical implications
The conductive polymers are interested for many industries. The reported data can be used by the formulators working in the R&D departments.
Social implications
The anti-corrosion ability of PANI/Pr3+ composite present a novel and high effective route against metal corrosion besides application of toxic corrosion.
Originality/value
The application of titanium dioxide coating in the field of architectural heritage is a great challenge. Therefore, the main objective of this study is to study the synthesis, characterization and corrosion inhibition performance of Pr3+ cations doped PANI nano-fibers as an anti-corrosion additive for AZ31 magnesium alloy in 3.5 Wt.% NaCl solution.
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This paper aims to achieve phosphating via optimal features of Mg metal as a suitable base coating, which is considered for other properties such as barrier properties against the…
Abstract
Purpose
This paper aims to achieve phosphating via optimal features of Mg metal as a suitable base coating, which is considered for other properties such as barrier properties against the passage of several factors.
Design/methodology/approach
In this research, in the phosphate bath, immersion time, temperature and the content of sodium nitrite as an accelerator were changed.
Findings
As a result, increasing the immersion time of AZ31 Mg alloy samples in the phosphating bath as well as increasing the ratio of sodium dodecyl sulfate (SDS) concentration to sodium nitrite concentration in the phosphating bath formulation increase the mass of phosphating formed per unit area of the Mg alloy. The results of the scanning electron microscope test showed phosphating is not completely formed in short immersion times, which is a thin and uneven layer.
Research limitations/implications
Mg and its alloys are sensitive to galvanic corrosion, which would lead to generating several holes in the metal. As such, it causes a decrease in mechanical stability as well as an unfavorable appearance.
Practical implications
Mg is used in several industries such as automobile and computer parts, mobile phones, astronaut compounds, sports goods and home appliances.
Social implications
Nevertheless, Mg has high chemical reactivity, so an oxide-hydroxide layer is formed on its surface, which has a harmful effect on the adhesion and uniformity of the coating applied on Mg.
Originality/value
By increasing the ratio of SDS concentration to sodium nitrite concentration in the phosphating bath, the corrosion resistance of the phosphating increases.
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– The purpose of this work was to prepare a catalyst-free microcapsules as self-healing agent in an automotive clearcoat to improve the scratch resistance of coatings.
Abstract
Purpose
The purpose of this work was to prepare a catalyst-free microcapsules as self-healing agent in an automotive clearcoat to improve the scratch resistance of coatings.
Design/methodology/approach
In this research, microcapsule with isophorone diisocyanate (IDPI) core and polyurethane shell were prepared and used in self-healing coatings. Microcapsules synthesised were characterised by thermal gravimeter and infrared spectra. The microcapsules were dispersed in an acrylic-melamine clearcoat, and the scratch resistance was evaluated.
Findings
The triplex product and the formed polyurethane bonds were confirmed by thermal gravimeter and infrared spectra. In addition, smooth spherical particles with a diameter of 1.5 to 1.7 micronmeters were observed by a scanning electron microscope. The microcapsules dispersed in an acrylic-melamine clearcoat increased the scratch resistance of coatings. Also, the self-healing feature of those coatings was proved.
Research limitations/implications
The size of microcapsules can affect its dispersion in the clearcoat and consequently affect the properties of the cured films.
Practical implications
The self-healing coatings are interested for many industries such as building and automotive industries. The reported data can be used by the formulators working in the R & D departments.
Social implications
Self-healing systems are considered as one of the smart coatings. Therefore, the developing of its knowledge can help to extend its usage to different applications.
Originality/value
The application of microcapsules in the coating as healing agents is a great challenge, which has been hardly investigated so far. In the current research, the effect of polyurethane-IDPI microcapsules in an automotive clearcoat as a self-healing coating was investigated.
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Pooneh Kardar, Morteza Ebrahimi and Saeed Bastani
The purpose of this work was to study the effect of chemical structure of reactive diluents on the curing behaviour and physical–mechanical properties of a titanium dioxide…
Abstract
Purpose
The purpose of this work was to study the effect of chemical structure of reactive diluents on the curing behaviour and physical–mechanical properties of a titanium dioxide pigmented UV-curable epoxy acrylate system.
Design/methodology/approach
Two different tri-functional and two different tetra-functional acrylate monomers were used as reactive diluents in the formulations. The curing behaviour of the formulations was studied by using photo-differential scanning calorimetry analysis. The rate of curing, conversion at the maximum rate and ultimate conversion for different formulations were calculated. In addition, the physical and mechanical characteristics of the cured films, including glass transition temperature and modulus, were measured by using a dynamic mechanical analysis technique.
Findings
The results showed that the ultimate conversion for non-pigmented pentaerythritol triacrylate (PETA) and trimethylol propane triacrylate (TMPTA) formulations were almost similar, but the interference effect of titanium dioxide particles on the curing of the PETA formulations was found to be more considerable in comparison to the TMPTA formulations. The extent of reaction for tetra-functional acrylate monomers was considerably less than those for tri-functional acrylate monomers. The Tg and storage modulus of non-pigmented PETA, TMPTA and pentaerythritol tetraacrylate (PE4TA) formulations were almost the same and higher than that for ditrimethylol propane tetraacrylate (DiTMP4TA) formulations. However, Tg and storage modulus of pigmented tetra-functional acrylate monomer formulations were higher than those for tri-acrylate monomer formulations.
Research limitations/implications
The curing conditions (temperature and UV intensity) can affect the network formation and consequently will affect on the properties of the cured films.
Practical implications
The pigmented UV-curable coatings are interested for many industries such as wood and automotive industries. The reported data can be used by the formulators working in the R&D departments. In addition, the results obtained can be used by the researchers who are active in the field of structure–property relationship for UV-curable coatings.
Social implications
UV-curing systems are considered as one of the most environment-friendly coatings system. Therefore, the developing of its knowledge can help to extend its usage to different applications.
Originality/value
The photopolymerisation of pigmented coatings is a great challenge and is hardly investigated in the literature. Therefore, in this research, the effect of chemical structure and functionality of different multifunctional acrylate monomers on the curing behaviour of pigmented formulations was investigated.
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