Oxygen vacancy is the most studied point defect and has been found to significantly influence the physical properties of zinc oxide (ZnO). By using atomic force microscopy (AFM), we show that the frictional properties on the ZnO surface at the nanoscale greatly depend on the amount of oxygen vacancies present in the surface layer and the ambient humidity. The photocatalytic effect (PCE) is used to qualitatively control the amount of oxygen vacancies in the surface layer of ZnO and reversibly switch the surface wettability between hydrophobic and superhydrophilic states. Because oxygen vacancies in the ZnO surface can attract ambient water molecules, during the AFM friction measurement, water meniscus can form between the asperities at the AFM tip-ZnO contact due to the capillary condensation, leading to negative dependence of friction on the logarithm of tip sliding velocity. Such dependence is found to be a strong function of relative humidity and can be reversibly manipulated by the PCE. Our results indicate that it is possible to control the frictional properties of ZnO surface at the nanoscale using optical approaches.

In this article, a silica/EVA/PP composite was prepared by melt‐blending nanosilica with polypropylene, and a surface‐modified BOPP film was prepared by using this as raw material. SEM studies have shown the special microscopic morphology of the surface and its cross section. X‐ray diffraction (XRD) characterized and analysed crystallinity, molecular orientation, and grain size in the modified film. Furthermore, the presence of microholes in the modified film was verified by positron annihilation spectroscopy. The results show that compared with the unmodified films, the modified BOPP films have higher crystallinity and smaller grain size. Its dense surface structure and reticular fibre bundle structure make the diffusion coefficient and solubility of ethyl acetate small in the film. The mechanical properties, barrier properties, heat resistance, and ink adhesion of this film have been significantly improved. Modified film can be used as the food packaging film which has high performance and low residue.

A neural-based fuzzy logic system was used to model and characterize adhesive behavior of the carbon-nitrogen-ceramic multilayer coating. The carbon-nitrogen ceramic multilayer coatings were prepared by an unbalanced magnetron (UBM) sputtering. Two kinds of carbon-nitrogen-ceramic multilayer coatings with Zr/ZrC/NC and Zr/ZrC/NZrC were adopted. An orthogonal array for reducing the number of required experiments is introduced. The critical load of the scratches to failure and the adhesive properties of a carbon-nitrogen-ceramic coating deposited on stainless steel substrate were carried out. A fuzzy logic system with neural networks in the UBM sputterings was made. The experimental results show the Zr/ZrC/NC films are found to have higher adhesive force, lower ratio of sp 3 to sp 2 structure and a somewhat lower coefficient of friction and tangential force than Zr/ZrC/NZrC films. A reliable multilayer process significantly improves the characteristics and structural features of carbon-nitrogen-ceramic coatings. Superior adhesive properties of the carbon-nitrogen-ceramic multilayer films in the UBM sputterings could be obtained. Further, the accurate modeling of a fuzzy logic system with neural networks can effectively estimate adhesion of the carbon-nitrogen-ceramic multilayer coatings in the UBM sputtering. It was experimentally confirmed adaptive fuzzy logic system predictors agree with the experiments.

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