Nanomaterials are attractive materials for researchers because they have essential characteristics in terms of their properties. Carbon has an ample range of crystalline allotropes. Some, such as graphite and diamond, have been known since ancient times, while new forms of carbon with potential for various applications have been discovered in recent decades. Since the discovery of graphene 20 years ago, research has increased on composite materials that take advantage of carbon structures for their electrical, thermal, and mechanical properties and their ability to be synthesized at the nanometer scale. Graphene has stood out above other nanomaterials due to its surprising properties and high impact on technological research, so its uses have diversified in different areas of science such as medicine, electronics, engineering, etc. This work aims to show some new and innovative applications of graphene, on which we can see its versatility as engineering material. It also seeks to show its potential in research and development processes for its use. These are key components of advanced graphene-based materials systems under active development, with an eye on the future of advanced materials science and technology.

Sodium montmorillonite nanoclay (Na⁺-MMT) was modified by plasma polymerization with methyl methacrylate (MMA) and styrene (St) as monomers and was denominated as Na⁺-MMT/MMA and Na⁺-MMT/St, respectively. This plasma modified nanoclay was used as reinforcement for polystyrene (PS) nanocomposites that were prepared by melt mixing. Pristine and modified Na⁺-MMT nanoclay were analyzed by the dispersion in various solvents, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The results confirmed a change in hydrophilicity of the modified Na⁺-MMT, as well as the presence of a polymeric material over its surface. The pristine PS/Na⁺-MMT and modified PS/Na⁺-MMT/MMA and PS/Na⁺-MMT/St nanocomposites were studied with X-ray diffraction (XRD), differential scanning calorimetry (DSC), and TGA, as well as mechanical properties. It was found that the PS/Na⁺-MMT/St nanocomposites presented better thermal properties and an improvement in Young’s modulus (YM) in compared to PS/Na⁺-MMT/MMA nanocomposites.

The use of cold plasma surface modification techniques has lately gained increasing interest as a complementary green option to modify the thermal stability of bio-based fibers, and thus make them more suitable for polymer reinforcing applications. In this study, commercial bleached hemp (CBH) fibers were modified using low-pressure rotatory plasma (LPRP) and atmospheric-pressure plasma jet (APPJ) devices to be further characterized by Fourier transform infrared spectroscopy―attenuated total reflectance mode (FTIR-ATR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). FTIR analysis evidenced the oxidation and crosslinking of cellulose chains. XRD analysis revealed a slight increase in interplanar distances of cellulose chains, that was attributed to the interchain insertion of functional groups. SEM images displayed much rougher surfaces for the treated CBH fibers than for the untreated one. TGA showed that LPRP (30 min treatment) and APPJ increased the thermal resistance of CBH fibers in 30 and 61 °C, respectively. For LPRP, a longer exposition time (180 min) provoked significant eroding without improving the thermal resistance. Finally, the cold plasma surface modification of bleached hemp fibers may well assist with the mechanical interlocking and thermal resistance (during processing) when applied in polymer reinforcing. El uso de técnicas de modificación de superficies por plasma frío ha venido ganado un interés creciente como una opción verde complementaria para modificar la estabilidad térmica de fibras bio-basadas, haciéndolas más aptas para reforzar polímeros. En este estudio, fibras comerciales de cáñamo blanqueado (CBH) fueron modificadas usando dispositivos de plasma de baja presión tipo rotatorio (LPRP) y plasma a presión atmosférica tipo jet (APPJ) para ser posteriormente caracterizadas mediante FTIR-ATR, XRD, SEM y TGA. El análisis por FTIR evidenció la oxidación y entrecruzamiento de las cadenas de celulosa superficiales. El análisis por XRD reveló un incremento en la distancia interplanar de las cadenas de celulosa, lo cual fue atribuido a la inserción de grupos funcionales entre cadenas. El análisis por SEM mostró una superficie mucho más rugosa para CBH tratadas que para las no tratada. TGA mostró que los tratamientos por LPRP (30 min) y APPJ incrementaron la resistencia térmica de las fibras de CBH en 30 y 61 °C, respectivamente. Para LPRP, una exposición más extendida (180 min) provocó una erosión significativa sin mejorar la resistencia térmica. Finalmente, la modificación con plasma frio de la superficie de las fibras de cáñamo blanqueado puede ayudar al acoplamiento mecánico y resistencia térmica (durante el procesamiento), cuando sean aplicadas en el reforzamiento de polímeros.