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1 – 10 of 495Amruta Joglekar-Athavale, Ganapati Shankarling, Satishchandra Dubey, Vinita Deshpande, Bikashkumar Jaiswal and Arun Nayak
The spectrally selective solar absorption paint is prepared from spinel-based mixed metal oxides with inorganic binder as a key component. Inorganic binder (furnace cement) is…
Abstract
Purpose
The spectrally selective solar absorption paint is prepared from spinel-based mixed metal oxides with inorganic binder as a key component. Inorganic binder (furnace cement) is blended with mixed metal oxide pigment during synthesis. High temperature stability upto 1,100ºC is achieved by the use of this modified coating system. The purpose of this paper is to work on solar selective coating synthesis, and application of a coating as a water-borne paint is the additive key feature that helps in reduction of solvent use.
Design/methodology/approach
The paint was formulated using water-based system, and the main component of colorant was made by mixed metal oxide–based spinel pigment and highly temperature stable inorganic binder.
Findings
The paint formed shows excellent absorptive power with low emittance even at high temperature. Optical and thermal properties were determined along with adhesion, abrasion and other properties. The solar absorptance for these samples were as = 0.93–0.95 with corresponding thermal emittance of eT = 0.096 (at room temperature) and 0.2–0.22 (at elevated temperature 100°C).
Originality/value
The paint formed shows excellent absorptive power with low emittance even at high temperature. The paint can be applied in solar absorptive tower system. The obtained results indicated excellent thermal stability of prepared paint coatings. As inorganic binder was used, the paint has reduction in solvent use, and being water as a base, it is environment friendly, easy to apply and durable at high temperatures, as the binder itself is stable up to 1,500ºC.
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Amruta Joglekar-Athavale and Ganapti S. Shankarling
A mixed metal oxide-based spinel ceramic pigment has been successfully synthesized incorporating inorganic, high-temperature stable furnace cement as an inbuilt binder. Step by…
Abstract
Purpose
A mixed metal oxide-based spinel ceramic pigment has been successfully synthesized incorporating inorganic, high-temperature stable furnace cement as an inbuilt binder. Step by step synthesis was done for the spinel and cement mix formulations.
Design/methodology/approach
The pigment mix was synthesized by a solid-solid method where the inorganic binder was incorporated in the mix. The results suggested that CoCuMn-based spinel ceramic pigment with cement mix could be obtained at an annealing temperature of 1,100ºC for 1 h and the size, morphology and crystallinity of spinel mix were greatly influenced by the calcination temperature.
Findings
The pigment mix synthesized was applied as a coating to different substrates such as aluminum, glass and Mild steel. The results revealed that spectral selectivity of TSSS paint coatings based on the CoMnCu spinel ceramic mix was much better than that of solvent-based coatings for high-temperature applications. The presence of cement as an inorganic binder makes the functioning and application of paint easy as it becomes that of a waterborne type.
Originality/value
Ease of application, stability at high temperatures, best absorptivity at the solar selective spectrum and excellent adhesion properties for the selected surface are the key features of the designed pigment system. The applied pigment mix was studied as a coating to get the results for solar selective system.
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L. Ismail, K. Ramesh, N.A. Mat Nor, S.K.M. Jamari, B. Vengadaesvaran and A.K. Arof
The purpose of this paper is to study the electrochemical, mechanical and thermal characteristics of polyester – epoxy coating systems using electrochemical impedance spectroscopy…
Abstract
Purpose
The purpose of this paper is to study the electrochemical, mechanical and thermal characteristics of polyester – epoxy coating systems using electrochemical impedance spectroscopy (EIS), pull-off test and differential scanning calorimetry (DSC). These are very important properties to evaluate the performance of a coating system. Proper measurement and analysis techniques are needed for a proper evaluation of these properties to ensure the coating performance.
Design/methodology/approach
Different ratios of polyester and epoxy resins have been blended to formulate good anticorrosive, mechanically strong and thermally stable binder coating system. EIS, pull-off test and DSC were used to evaluate these properties.
Findings
The sample containing 90 wt.% polyester exhibited the best corrosion resistance from the beginning until the end of exposure time. The value of corrosion resistance (Rc) obtained on the 30th day of exposure was found to be 2.89 × 108 ohm cm−2. The glass transition temperature (Tg) was found to be increasing with the incorporation of epoxy to the binder system. The result from pull-off test showed the best adhesion with the sample containing 90 wt.% polyester which also has the lowest Tg promoted better adhesion properties.
Practical implications
The curing time must be reduced for practical applications.
Originality/value
Hybrid coatings systems have been formulated. This paper discusses on the highest coating resistance obtained polymer-substrate mechanical properties and thermal characteristic of the polyester/epoxy binder resin using DSC.
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The purpose of this paper is to develop a novel organic‐inorganic (epoxy‐silicone) hybrid resin for application in heat resistant surface coatings.
Abstract
Purpose
The purpose of this paper is to develop a novel organic‐inorganic (epoxy‐silicone) hybrid resin for application in heat resistant surface coatings.
Design/methodology/approach
Thermally stable aminosilicone resin was prepared by using diethoxydimethyl silane and γ‐aminopropyldiethoxy methyl silane.
Findings
The hybrid epoxy silicone resin shows significant properties such as toughness, chemical resistance and thermal stability.
Research limitations/implications
The prepared amino siloxane was cured by commercially available epoxy resin PG 100 and toluene diisocyanate in different ratios at high as well as at room temperature to develop high‐temperature vulcanisation and room temperature vulcanisation resin systems.
Practical implications
The hybrid epoxy silicone resin may be used as heat resistant coatings due to their low shrinkage and lesser internal stress.
Originality/value
The developed hybrid epoxy silicone resin was novel for application in thermally stable coatings.
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M. Bajpai, Sunita Seth, A.K. Saxena and Ashok Ranjan
Some thermally stable epoxy coatings have been developed using functional aminosl.ilanes viz, N‐[3‐(trimethoxysilyl) propyl] ethylenediamine and copolymer of aminopropylmethyl…
Abstract
Some thermally stable epoxy coatings have been developed using functional aminosl.ilanes viz, N‐[3‐(trimethoxysilyl) propyl] ethylenediamine and copolymer of aminopropylmethyl dimethylsiloxane in different ratio. It has been observed that use of silicon compounds invariably enhances the thermal stabililty, chemical resistance and corrosion resistance of epoxy coating. It has also been observed that silane bearing triethoxy group gave better adherence properities whereas silicone gave better thermal stability. The degradation kinetics showed that the reactions were of first order.
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Walaa M. Abd El-Gawad and Wael Mohamed Abdelmaksoud
This study aims to investigate the possibility of synthesizing cobalt doped willemite ceramic blue pigment by using Egyptian white sand as environmental and economical raw…
Abstract
Purpose
This study aims to investigate the possibility of synthesizing cobalt doped willemite ceramic blue pigment by using Egyptian white sand as environmental and economical raw material for multi-applications in coatings and inks.
Design/methodology/approach
After the synthesis process, the prepared blue pigment was characterized via X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray analysis technique. Then the blue pigment was integrated into both coating and ink formulations. The effect of the prepared multifunctional coatings on corrosion resistance and thermal stability was evaluated using different standard tests. Also, the effect of inclusion of blue pigment in flexographic printing ink formulation was done.
Findings
The results showed that the coating containing the cobalt doped willemite blue pigment offered good anticorrosive performance and high thermal stability. Additionally, the presented results revealed that integration of the blue pigment in flexographic printing ink formulation enhanced fineness, gloss, viscosity and color more than the commercial one “FX 430–201.”
Originality/value
In conclusion, relied on the eco-friendly principle which can be regarded as an economic and green strategy, it can be obtained that this new pigment can provide good multifunctions such as corrosion resistance and thermal stability in coatings and good fineness, gloss, viscosity and color in inks which can enable them to be widely applied in different industries.
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A.K. Khan, M.S. Saxena and S. Chandra
The research of Swarts in Belgium in the early nineties underlines organic fluorine chemistry and the industry that has grown around it. Swarts and co‐workers studied the reaction…
Abstract
The research of Swarts in Belgium in the early nineties underlines organic fluorine chemistry and the industry that has grown around it. Swarts and co‐workers studied the reaction of antimony trifluoride with chlorine‐containing hydrocarbons in great deals as a means of replacing chlorine with fluorine.
A. Syafiq, A.K. Pandey, Vengadaesvaran Balakrishnan, Syed Shahabuddin and Nasrudin Abd Rahim
This paper aims to investigate the thermal stability and hydrophobicity of difference alkyl chain of silanes with silicon (Si) micro- and nanoparticles.
Abstract
Purpose
This paper aims to investigate the thermal stability and hydrophobicity of difference alkyl chain of silanes with silicon (Si) micro- and nanoparticles.
Design/methodology/approach
Sol-gel methods have been used to design superhydrophobic glass substrates through surface modification by using low-surface-energy Isooctyl trimethoxysilane (ITMS) and Ethyl trimethoxysilane (ETMS) solution. Hierarchical double-rough scale solid surface was built by Si micro- and nanoparticles to enhance the surface roughness. The prepared sol was applied onto glass substrate using dip-coating method and was dried at control temperature of 400°C inside the tube furnace.
Findings
The glass substrate achieved the water contact angle as high as 154 ± 2° and 150.4 ± 2° for Si/ITMS and Si/ETMS films, respectively. The Si/ITMS and Si/ETMS also were equipped with low sliding angle as low as 3° and 5°, respectively. The Si micro- and nanoparticles in the coating system have created nanopillars between them, which will suspend the water droplets. Both superhydrophobic coatings have showed good stability against high temperature up to 200°C as there are no changes in WCA shown by both coatings. Si/ITMS film sustains its superhydrophobicity after impacting with further temperature up to 400°C and turns hydrophobic state at 450°C.
Research limitations/implications
Findings will be useful to develop superhydrophobic coatings with high thermal stability.
Practical implications
Sol method provides a suitable medium for the combination of organic-inorganic network to achieve high hydrophobicity with optimum surface roughness.
Originality/value
Application of different alkyl chain groups of silane resin blending with micro- and nanoparticles of Si pigments develops superhydrophobic coatings with high thermal stability.
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Qun Yan and Chuanxian Li
The purpose of this paper is to synthesize polypyrrole/SiO2 composite coating on 316 stainless steel (316SS) by cyclic voltammogram and preliminary do research about the valuable…
Abstract
Purpose
The purpose of this paper is to synthesize polypyrrole/SiO2 composite coating on 316 stainless steel (316SS) by cyclic voltammogram and preliminary do research about the valuable effects of SiO2 particle incorporation within the polymer matrix.
Design/methodology/approach
This study is based on elaboration of coating by electrochemical process and of SiO2 by a sol-gel process.
Findings
Electrochemical impedance studies revealed that compared with polypyrrole (PPy), PPy-SiO2 coating acts as a more protective layer on 316SS against corrosion in 3.5 per cent NaCl. Scanning electron microscopy studies revealed that the PPy-SiO2-coated 316SS showed more uniform and compact morphology.
Originality/value
To fully disperse SiO2, a sol-gel method is used. Hydroxyl group is generated on the surface of inorganic particle by the sol-gel method, which improves the inorganic particle dispersion.
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R. Otáhal, D. Veselý, J. Násadová, V. Zíma, P. Němec and P. Kalenda
The purpose of this paper is to study properties of intumescent coatings based on a silicone‐epoxy hybrid resin (with an aminosilane as hardener). In the first part of this study…
Abstract
Purpose
The purpose of this paper is to study properties of intumescent coatings based on a silicone‐epoxy hybrid resin (with an aminosilane as hardener). In the first part of this study, fire‐resistance behaviour of the intumescent coating based on silicone‐epoxy resin containing intumescent additives is evaluated. The second part assesses the effect of mineral fibres on fire‐resistant properties of intumescent coatings based on the silicone‐epoxy resin.
Design/methodology/approach
Thermal degradation and char formation of coatings were investigated by Thermogravimetric analyses, X‐ray diffraction and X‐ray fluorescence and infrared spectroscopy (FTIR). The salt spray corrosion test was applied to study the resistance of intumescent coatings. Anticorrosion and fire‐resistant properties after one, three and seven days of exposure were evaluated.
Findings
It was shown that a silicone‐epoxy hybrid resin is suitable for applications in the field of intumescent coatings. Intumescent coatings based on this resin form a thermally stable thin ceramic‐like layer, which improves the thermal insulation properties of the char. Mineral fibres reinforced the char structure and thus improved fire‐resistant properties of intumescent coating before as well as after the salt spray test. Mineral fibres also improved anticorrosion properties.
Research limitations/implications
This paper discusses only the effect of mineral fibres on properties of intumescent coatings.
Originality/value
A silicone‐epoxy hybrid resin has not previously been used in intumescent coatings. This type of intumescent coating can be used as an effective passive fire protection system for steel constructions.
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