Carbon nanotubes (CNTs) functionalization was carried out with radio frequency plasma in different working gas Ar/O2 and Ar/O2/N2 at different plasma powers to synthesize epoxy nanocomposites. After the CNT's had been treated, the Fourier transform infrared (FTIR) spectroscopy showed an additional peak at 1,740 cm−1, attributed to carboxylic groups, corroborating the X‐ray photoelectron spectroscopy that shows attachment of oxygen groups, which indicates CNTs' functionalization. Raman shows an increase in the ID/IG ratio, attributed to an increased number of defects, in agreement with transmission electron microscope images that show a nanocoating on CNTs' surfaces. Functionalization carried out with low power plasma makes also some C‐N bonds possible, preserving the aromatic carbons of the CNTs' structure. Nanocomposites showed better dispersion and distribution for samples with CNTs treated by Ar/O2/N2 plasma. Furthermore, there was a decrease in Tg when compared with neat epoxy, especially for samples with more nitrogen atoms attached to the CNTs. Mechanical properties presented an improvement, which is specially related to a better phase interaction led by the nitrogen presence on the CNTs' surface. POLYM. COMPOS., 40:E1162–E1171, 2019. © 2018 Society of Plastics Engineers

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This communication aims to propose new insights of Nb2O5-based coatings on the 316L SS surface with great prospects to be used in the dentistry field as brackets. The Nb2O5 thin film was incorporated into the 316L SS by using PVD method. For this purpose, the studied system was characterized structurally and morphologically by using AFM, FTIR-IRRAS, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Biological assays were performed using human gingival fibroblast cell-line HGF-1. In agreement with FTIR and Raman results, the XPS technique indicates that Nb is present in an oxidation state assigned to Nb2O5. Furthermore, the coatings produced by PVD technique are less toxic and induces less inflammation in gingival cells (cell-line HGF-1), suggesting the strategy of use Nb2O5 thin film to cover the 316L SS promoted since its protection of the physiological environment to its biocompatibility improvement.

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