This article describes how crystalline or fibrous nanocellulose influences the mechanical properties of paper substrate. In this context, we used commercially available cellulose nanocrystals, mechanically prepared cellulose nanofibers dispersed in water or ethanol, and carboxy cellulose nanofibers. Selective reinforcement of the paper treated with the nanocellulose samples mentioned above was observed. The change in the fibre structure was assessed using scanning electron microscopy, roentgenography, and spectroscopy techniques. In addition, the effect of nanocellulose coating on physical properties was evaluated, specifically tensile index, elongation coefficient, Elmendorf tear resistance, Bendtsen surface roughness, Bendtsen air permeability, and bending strength. It can be concluded that the observed decrease in the strength properties of the paper after applying some NC compositions is due to the loss of potential disturbances in hydrogen bonds between the nanocellulose dispersed in ethanol and the paper substrate. On the other hand, significantly increased strength was observed in the case of paper reinforced with nanocellulose functionalized with carboxyl groups.

The application of ionic liquids (ILs) has grown enormously, from their use as simple solvents, catalysts, media in separation science, or electrolytes to that as task-specific, tunable molecular machines with appropriate properties. A thorough understanding of these properties and structure–property relationships is needed to fully exploit their potential, open new directions in IL-based research and, finally, properly implement the appropriate applications. In this work, we investigated the structure–properties relationships of a series of alkyltriethylammonium bis(trifluoromethanesulfonyl)imide [TEA-R][TFSI] ionic liquids in relation to their thermal behavior, structure organization, and self-diffusion coefficients in the bulk state using DSC, FT-IR, SAXS, and NMR diffusometry techniques. The phase transition temperatures were determined, indicating alkyl chain dependency. Fourier-transformed infrared spectroscopy studies revealed the structuration of the ionic liquids along with alkyl chain elongation. SAXS experiments clearly demonstrated the existence of polar/non-polar domains. The alkyl chain length influenced the expansion of the non-polar domains, leading to the expansion between cation heads in polar regions of the structured IL. ¹H NMR self-diffusion coefficients indicated that alkyl chain elongation generally caused the lowering of the self-diffusion coefficients. Moreover, we show that the diffusion of anions and cations of ILs is similar, even though they vary in their size.

In the present work we demonstrate a simple and effective way to produce bulk quantities of graphene material. For the first time, graphite oxide (GO), synthesized by electrochemical treatment of natural graphite in HClO₄ aqueous solution, was used to obtain thermally exfoliated-reduced graphite oxide (TRGO). Herein, GO was thermally exfoliated and reduced at 500 °C in air, giving the final product of TRGO. Due to shock treatment, the volume of the synthesized TRGO drastically increased compared to the starting GO. Furthermore, the exfoliation process resulted in a significant decrease in the concentration of oxygen functionalities. The choice of GO exfoliation temperature was preceded by thermogravimetric analysis (TGA). TRGO was characterized using X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis.

We report the observations of electronic properties of graphene oxide and reduced graphene oxide, performed with electron paramagnetic resonance technique in a broad temperature range. Both materials were examined in pure form and saturated with air, helium, and heavy water molecules. We show that spin localization strongly depends on the type and amount of molecules adsorbed at the graphene layer edges (and possible in-plane defects). Physical and chemical states of edges play crucial role in electrical transport within graphene-based materials, with hopping as the leading mechanism of charge carrier transport. Presented results are a good basis to understand the electronic properties of other carbon structures made of graphene-like building blocks. Most active carbons show some degree of functionalization and are known of having good adsorptive properties; thus, controlling both phenomena is important for many applications. Sample treatment with temperature, vacuum, and various adsorbents allowed for the observation of a possible metal-insulator transition and sorption pumping effects. The influence of adsorption on the localization phenomena in graphene would be very important if to consider the graphene-based material as possible candidates for the future spintronics that works in ambient conditions.