Boron Nitride Nanosheet Coatings with Controllable Water Repellency

The growth, structure, and properties of two-dimensional boron nitride (BN) nanostructures synthesized by a thermal chemical vapor deposition method have been systematically investigated. Most of the BN nanosheets (BNNSs),were less than 5 min thickness, and their purity was confirmed by X-ray energy dispersive spectroscopy, X-ray photoelectron spectroscopy; electron energy loss spectroscopy, and Raman spectroscopy. The Weds of the process variables on the morphology and roughness of the coatings were studied using atomic force microscopy and. scanning electron microscopy. A smooth BN coating was obtained at 900 degrees C, while compact BNNS. coatings composed of partially vertically aligned nanosheets could be achieved at 1000 degrees C and higher temperatures. These nanosheets were mostly separated and exhibited high surface area especially at higher synthesis temperatures. The nonweeting properties of the BNNS coatings were Independent of the water pH and were examined by contact angle goniometry. The present results enable a convenient growth of pure BNNS coatings with controllable levels of water repellency,. ranging from partial hydrophilicity to superhydrophobicity with contact angles exceeding 150 degrees.