Mentally friendly chemicals and work well for

  • No School
  • AA 1
  • 14

This preview shows page 1 - 3 out of 14 pages.

mentally friendly chemicals and work well for improving adhesion at the metal/coating interface. Silicon-organic based sol–gel chemistry is more developed nowadays when compared with other metal–organic based precursors. Hybrid coatings are mainly prepared from the sol of alkoxide mixed with organic polymers or organoalkoxy- silanes. R 0 -Si(OR) 3 bearing R 0 = various organic func- tional groups are the most used organic molecules nowadays when compared with other organic molecules to S. Zheng ( & ) ± J. Li Department of Applied Chemistry, Nanjing University of Aeronautics and Astronautics, 210016 Nanjing, China e-mail: [email protected] 123 J Sol-Gel Sci Technol (2010) 54:174–187 DOI 10.1007/s10971-010-2173-1
Image of page 1
form strong chemical interactions with organic components or inorganic sols. Degradation of metals and application of toxicants (such as chromate salt) have always been a concern for organic finishing. The hydrophobicity and adhesive strength and anticorrosion properties of inorganic–organic sol–gel hybrid coatings suggest their potential utility as techno- logically compatible alternatives to conventional coatings [ 1 ]. Hybrid coatings have been prepared to improve the corrosion resistance properties of steel, zinc, aluminum, and magnesium substrates and designed to offer environ- mentally friendly alternatives in pre-treatment coating systems to existing chromate-based anti-corrosion coatings [ 2 ]. Zheludkevich [ 3 ] has reviewed sol–gel chemistry and sol–gel coatings for corrosion protection of metals in 2005. The present paper complements the advancement and provides a reasonable understanding about hybrid coatings for corrosion protection of metals: the function of inorganic and organic components in hybrid coatings, the green long- term corrosion inhibitors and the super-hydrophobic hybrid coatings for fighting corrosion. Either inorganic or organic coatings have limitations. It is evident that all the factors that reduce these limitations improve corrosion protection. These factors are discussed from the standpoint of the influence of inorganic or organic components on hybrid coatings performances as following. 2 Influence of inorganic components The function of inorganic sol is: (1) increasing adhesion between metals and hybrid coatings; (2) being used as adhesion promoters for pre-treatments of metals; (3) improving comprehensive performances of polymer in hybrid coatings. Typical advantages of traditional polymer coatings sys- tems are they are mechanically flexible and tough, but have poor abrasion and thermal resistance. Inorganic sols provide a good adhesion layer between metallic substrate and organic coatings, which is related to the low oxygen diffusion and the good mechanical properties [ 4 ]. Silica-polymer hybrid film coatings were found to greatly improve corrosion resistance of stainless steel and Zn plated steel [ 5 ].
Image of page 2
Image of page 3

You've reached the end of your free preview.

Want to read all 14 pages?

  • Fall '19
  • TEOS

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask ( soon) You can ask (will expire )
Answers in as fast as 15 minutes
A+ icon
Ask Expert Tutors