| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 692234 | Progress in Organic Coatings | 2015 | 8 Pages |
•Silica nano particles were prepared from silicon alkoxide in alcoholic solution.•TGA/DTA analysis shows that the composite coating is stable up to 577 K.•TEM study shows the particle size of silica is 50–70 nm and the composite is 200 nm.•Nano silica coating shows better wear resistance than microsilica coating.•Nano silica composite coating performs well in salt spray and EIS in NaCl solution.
Recent developments made in the synthesis of nano-materials have demonstrated their contribution in the field of protective coatings. Sol–gel method is the simple and elegant technique for the preparation of nanosilica particles. The nano-silica composites were prepared by mixing the epoxy compounds and polyamide hardener and characterized by using X-ray powder diffraction (XRD), thermal analysis (TGA and DTA), FT-IR spectroscopic technique and SEM analysis. The size of the nano particles was confirmed by transmission electron microscopy (TEM). Mechanical properties of the nano-silica epoxy composites were determined by ASTM method. The wear index data of the nano-silica incorporated epoxy composite were found to be 32 mg/1000 cycles. Corrosion performance was evaluated by salt spray test and electrochemical impedance measurements. The nano-silica epoxy composite coatings withstood 720 h in salt spray test, whereas the micro silica coatings withstood up to 650 h. Electrochemical impedance spectroscopy results of the nano-silica epoxy composite coatings showed a resistance of 2.36 × 106 Ω cm2 after 30 days of immersion in 3% NaCl solution, whereas micro silica incorporated coatings showed a resistance of 5.41 × 104 Ω cm2 under similar conditions.
