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The density functional theory (DFT) has been used to study the surface interactions of pristine, Ni- and Pt-doped (4,4), (5,5), (7,7) and (8,8) boron nitride nanotubes (BNNTs) with ammonia (NH 3 ) molecules. To verify the impact of external electric field (EF) on the surface interactions between the nanotubes and adsorbed NH 3 molecules, in this work, the NH 3 /(4,4) BNNTs adsorbed complex system under an applied EF with strength of 3 × 10 −2  a.u. and 4 × 10 −2  a.u., along the z axis (perpendicular to the tube axis) has been investigated. It was shown that after doping of Ni and Pt atoms, the primary symmetry of BNNTs was decreased, enhancing the chemical activity of BNNTs towards NH 3 molecules and subsequent resulting in dramatic changes of their electronic properties. Our overall results indicated that, in addition to the Ni and Pt doping, the applied external EF could enhance the sensitivity of BNNTs toward NH 3 molecule, which can be considered as a new strategy of sensor fabrication. [ABSTRACT FROM AUTHOR]

Capillary-porous structure of wood modified with boron-nitrogen compounds was studies by sorption methods. Specific surface area of the suport was found to be reduced up to three folds.Changes of structure of the wood surface layer treated with aqueas solutions of boric acid and ethanolamines as well as the possibility of forming 4-coordinate boron-nitrogen compounds in situ, directly on the wood surface, were investigated. Stepwise treatment of wood surface with boric acid and ethanolamines in different order was found not to cause significant changes in the capillary-porous structure, which is apparently due to the difficulties of formation of 4-coordinate boron-nitrogen compounds in situ. [ABSTRACT FROM AUTHOR]