This study looks at the effects of imposed confinement on morphology related properties in vapor grown carbon nanofibers (VGCF) polypropylene nanocomposite filaments. Different levels of imposed confinement are achieved through varying the content of the VGCF and the dimensions of the nanocomposite filaments. The resulting molecular confinement is apparent through a sharp increase (termed the inversion point) in a number of properties at low filament diameters, which is associated with a formation of a 'shish kebab' structure and a transition from a skin/core morphology to an axially oriented lamellar structure.

Cubic boron nitride (c‐BN) has an ultrahardness and a large bandgap energy like diamond. In the last 30 years, most of the attention has been directed towards the mechanical and electronic applications of c‐BN, while its biological potential has been overlooked. The authors report in vitro biocompatibility of high‐quality c‐BN films prepared by plasma‐enhanced chemical vapor deposition using the chemistry of fluorine. c‐BN films become superhydrophilic when chemical‐treated in hydrogen and nitrogen plasmas with or without the impact of low‐energy ions due to a marked increase in polar part of the surface free energy by removal of the fluorine atoms terminating c‐BN surfaces. Satisfactory proliferation and differentiation of osteoblastic cells comparable with a control sample and a superhydrophilic nanocrystalline diamond film, and the formation of mineral deposits by biomineralization are confirmed on the superhydrophilic c‐BN films with negative values of zeta potential. The results demonstrate a high potential of c‐BN as a noncytotoxic ultrahard coating material for biological and biomedical applications.