Use of a sol-gel hybrid coating composed by a fluoropolymer and silica for the mitigation of mineral fouling in heat exchangers

Oldani, V.; Sergi, Gabriele; Pirola, Carlo; Bianchi, Claudia L.

doi:10.1016/j.applthermaleng.2016.06.014

Cited by 20 publications

(5 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This result indicates that there is no induction period for PS and there are different induction periods for each Fe-Al MNS sample, which is similar to previous research [32]. Bogacz [33] found that there was a significant influence between the wettability of the heat-transfer surface and the fouling adhesion, which was more significant than the influence of roughness. For the heat-transfer surface with the lower contact angle, the lower removal rate appeared for the deposited fouling on the surface [34,35].…”

Section: Antifouling Property Of Fe-al Mns Samplesupporting

confidence: 89%

Fabrication of Fe‒Al Coatings with Micro/Nanostructures for Antifouling Applications

Wang

Fan

et al. 2020

Coatings

View full text Add to dashboard Cite

Fouling is one of the common problems in heat-transfer applications, resulting in higher fouling resistance, and lower heat-transfer coefficient. This paper introduces the design and fabrication of an Fe–Al coating with micro/nanostructures on low-carbon steel by electrical discharge coating (EDC) technology to improve the antifouling property. The Fe–Al coating with micro/nanostructures is characterized by a large number of micro/nanostructures and superior anti-fouling property, which is attributed to its hydrophobic surface. The antifouling property, fouling induction period and contact angle of the Fe–Al coating with micro/nanostructures increase with the increasing gap voltage. Compared with the polished surface of low-carbon steel, the Fe–Al coating with micro/nanostructures extends the induction period from 214 to 1350 min, with a heat flux of 98 kW·m−2. After 50 adhesion tests, the contact angle of the Fe–Al coating with micro/nanostructures decreases from 6.81% to 27.52%, which indicates that the Fe–Al coating with micro/nanostructures is durable and suitable for industrial applications.

show abstract

Section: Antifouling Property Of Fe-al Mns Samplesupporting

confidence: 89%

Fabrication of Fe‒Al Coatings with Micro/Nanostructures for Antifouling Applications

Wang

Fan

et al. 2020

Coatings

View full text Add to dashboard Cite

show abstract

“…In the last few years, the literature reported on this type of coatings increased notably [60,[291][292][293][296][297][298][299]. Numerous techniques and methods have been used in the development of superhydrophobic surfaces [300][301][302], and the sol-gel process, as the versatile method that it is, was no exception [294,299,[303][304][305][306][307]. Recently, a very detailed and comprehensive review, focused on the latest developments of superhydrophobic coatings for corrosion mitigation, has been published [308].…”

Section: Coatings With Superhydrophobic Functionmentioning

confidence: 99%

Hybrid Sol–gel Coatings for Corrosion Mitigation: A Critical Review

Figueira

2020

Polymers

View full text Add to dashboard Cite

The corrosion process is a major source of metallic material degradation, particularly in aggressive environments, such as marine ones. Corrosion progression affects the service life of a given metallic structure, which may end in structural failure, leakage, product loss and environmental pollution linked to large financial costs. According to NACE, the annual cost of corrosion worldwide was estimated, in 2016, to be around 3%-4% of the world's gross domestic product. Therefore, the use of methodologies for corrosion mitigation are extremely important. The approaches used can be passive or active. A passive approach is preventive and may be achieved by emplacing a barrier layer, such as a coating that hinders the contact of the metallic substrate with the aggressive environment. An active approach is generally employed when the corrosion is set in. That seeks to reduce the corrosion rate when the protective barrier is already damaged and the aggressive species (i.e., corrosive agents) are in contact with the metallic substrate. In this case, this is more a remediation methodology than a preventive action, such as the use of coatings. The sol-gel synthesis process, over the past few decades, gained remarkable importance in diverse areas of application. Sol-gel allows the combination of inorganic and organic materials in a single-phase and has led to the development of organic-inorganic hybrid (OIH) coatings for several applications, including for corrosion mitigation. This manuscript succinctly reviews the fundamentals of sol-gel concepts and the parameters that influence the processing techniques. The state-of-the-art of the OIH sol-gel coatings reported in the last few years for corrosion protection, are also assessed. Lastly, a brief perspective on the limitations, standing challenges and future perspectives of the field are critically discussed.Polymers 2020, 12, 689 The development of OIH sol-gel coatings, based on siloxanes, for corrosion mitigation, has been widely studied in the last few years [2,31,[36][37][38]. Numerous studies have been conducted since the early 1990s [39,40]. The studies performed showed that siloxanes were effective in mitigating the corrosion processes of different metallic substrates. This development was mainly due to the need for alternative environmentally friend materials and processes to replace the traditional chromium-based pre-treatments. Hexavalent chromium (Cr (VI)) is carcinogenic and shows high environmental toxicity and its use has been forbidden since 2006. However, Cr(VI) based pre-treatments improve the coating adherence to the substrate and are effective corrosion inhibitors [41][42][43] which make its replacement challenging. The use of the sol-gel method to produce OIH coatings for corrosion mitigation suits the main requirements of what should be an environmentally friendly process (i.e., excludes washing stages; it is a waste-free method) and allows one to obtain coatings with high purity and specific pore volumes and surface areas. Since it is a mild synthesis...

show abstract

“…The SCA copolymerizes with the functional polymer through reactions with these bonds to give [polymer]–X–Si(−R) n (−OH) 3– n . In comparison to hydrocarbons as polyethylene R–(CH 2 –CH 2 −) m , fluorocarbons such as perfluoroalkyl R–(CF 2 −) m and poly(vinylidene difluoride) R–(CF 2 –CH 2 −) m show high hydrophobicity and abrasion resistance, when used as polymers. − The flexibility of the polymer increases when an ether group is included, such as perfluoropolyether R–((CF 2 −) 3 O−) m . − …”

Section: Introductionmentioning

confidence: 99%

First-Principles Simulation Study on the Weakening of Silane Coupling to Silica under Alkaline Conditions

Ogata

Uranagase

2021

J. Phys. Chem. C

View full text Add to dashboard Cite

Silane coupling is commonly used to connect organic polymers to inorganic substrates for surface modification and composite material fabrication. It is known that the covalent bonds that form between the silane coupling agent (SCA) and hydroxylated SiO 2 weaken under alkaline conditions. In the present work, we theoretically investigated the microscopic mechanisms of this phenomenon by combining first-principles calculations of the deprotonation free energy with density functional theory (DFT), bond-breaking transition-state barrier energy calculations, and DFT-based molecular dynamics (MD) simulations. We found that the following occurs under alkaline conditions: (i) the terminal −OH of SiO 2 (001) is significantly deprotonated, while the −OH group of the SCA is hardly deprotonated; (ii) the transition-state barrier energy to break the Si−O bond between the SCA and SiO 2 (001) becomes less than 1 eV with the assistance of H 2 O dissociation when 50% of the terminal −OH groups on SiO 2 (001) is deprotonated; and (iii) the predicted Si− O bond-breaking reactions occurred in DFT−MD simulations with realistic settings.

show abstract

Use of a sol-gel hybrid coating composed by a fluoropolymer and silica for the mitigation of mineral fouling in heat exchangers

Cited by 20 publications

References 24 publications

Fabrication of Fe‒Al Coatings with Micro/Nanostructures for Antifouling Applications

Fabrication of Fe‒Al Coatings with Micro/Nanostructures for Antifouling Applications

Hybrid Sol–gel Coatings for Corrosion Mitigation: A Critical Review

First-Principles Simulation Study on the Weakening of Silane Coupling to Silica under Alkaline Conditions

Contact Info

Product

Resources

About