Synthesis of nanostructural turbostratic and hexagonal boron nitride coatings on carbon fiber cloths by dip-coating

The fabricating and characterization of boron nitride coating onto carbon fiber cloths via dip-coating process with boric acid and urea as precursors, followed by nitriding in a nitrogen flow were done in this study. Temperature and dip-coating cycles were considered as variables to find out optimum amounts. Dip-coating process has done in 1, 2 and 4 cycles. Also, nitridation process was done in different temperatures of 650 and 1000 degrees C. The results show that boron nitride coatings exhibited a pebble-like structure. The SEM micrographs indicated that the thickness of nanostructural coatings among 1, 2 and 4 cycles of dip-coating is about 55, 120 and 210 nm, respectively. By increasing dip-coating cycles, smoother surface was developed. The FT-IR and XRD results revealed that the boron nitride film fabricated at 650 degrees C has turbostratic microstructure and by increasing the nitridating temperature to 1000 degrees C, hexagonal boron nitride phase was indicated through the film. Thermal analysis revealed that boron nitride crystallization starts at temperature,of 600 degrees C. (C) 2016 Elsevier B.V. All rights reserved.