Plasma surface functionalization of boron nitride nano-sheets

On silicon substrates, boron nitride nanosheets (BNNS) consisting of interconnected hexagonal boron nitride nano-layers were produced via chemical vapor deposition process at 1200 degrees C whose rouglmess's are at the micrometer- and nanometer-scale. The BNNS were functionalized in argon plasma admixed with ammonia or nitrogen or oxygen. The samples were characterized to investigate the surface chemistry and structural changes after plasma treatment using X-ray photoelectron spectroscope and Micro-Raman spectroscope techniques, respectively. While no significant changes in the surface features, upon plasma treatments of the BNNS, were noticed during SEM and TEM examination, the oxygen functional groups, however, were found to have been incorporated in varying amounts depending on the plasma type. As compared to untreated BNNS, the plasma functionalization treatments made BNNS less hydrophobic. The wettability of the nanostructures, as measured form the water contact angle measurements, is discussed by referring to changes in surface chemistry after plasma treatment.