Influence of Clay size on corrosion protection by Clay nanocomposite thin films

Journal Article · Fri Dec 27 00:00:00 EST 2019 · Progress in Organic Coatings

DOI:https://doi.org/10.1016/j.porgcoat.2019.105489· OSTI ID:1595018

Melia, Michael A. ^[1]; Percival, Stephen J. ^[1]; Qin, Shuang ^[2]; Barrick, Erin ^[3]; Spoerke, Erik ^[1]; Grunlan, Jaime ^[2]; Schindelholz, Eric J. ^[1]

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1. The Ohio State Univ., Columbus, OH (United States)
2. Texas A & M Univ., College Station, TX (United States)
3. Lehigh Univ., Bethlehem, PA (United States)

In this work, the influence of clay platelet size on the corrosion barrier performance of highly-aligned polymer clay nanocomposite (PCN) thin films was examined. Layer-by-layer (LbL) deposition of alternating branched polyethylenimine (PEI) and either laponite (LAP), montromorillonite (MMT) or vermiculite (VMT) clay platelets were assembled on mild steel plates to obtain 20 bilayer (BL) films and cross-linked using glutaraldehyde after deposition. The clay platelets were chosen based on their aspect ratio, approximately 30:1, 400:1, and 2000:1, respectively. Electrochemical impedance spectroscopy of the coated steel plates during immersion showed corrosion rates and coating permeability followed LAP > MMT > VMT for up to 7 days of exposure in 0.6 M NaCl. The PEI/VMT films, ~250 nm thick, slowed corrosion by a factor of >1000 compared to bare steel. The results support the premise that high aspect ratio clay platelets can improve the corrosion barrier efficacy of LbL PCN films by decreasing film permeability and provide exceptional protection to steel in saline environments compared to other thin multilayer coatings and pretreatments.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE; USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC04-94AL85000; NA0003525
• OSTI ID: 1595018
• Alternate ID(s): OSTI ID: 1698107
• Report Number(s): SAND--2019-15104J; 682194
• Journal Information: Progress in Organic Coatings, Journal Name: Progress in Organic Coatings Journal Issue: C Vol. 140; ISSN 0300-9440
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
Anti-corrosion
Coating
Electrochemical impedance
Layer-by-layer assembly
Permeability
Polymer