Structural transformations of nano-systems show properties different from their 3D bulk analogs. The mechanism of transformation is different due to the nano-object size or nanometric confinement. This field has not yet been fully explored and requires more fundamental studies which may lead to future application, e.g., in nanoporous systems characterization. Properties of methane adsorbed in confined geometries are interesting from both fundamental and practical points of view. At ambient temperatures supercritical adsorption is studied for possible methane storage applications. At the same time, the analysis of methane’s low temperature adsorption properties is essential for understanding the mechanism of adsorption as a function of temperature, pore size, pore topology and heterogeneity. The temperature dependence of structures of adsorbed phases allows one to understand evolution of confined phases in nano-space. In this work we compare the mechanism of adsorption and structural transformations of methane confined in (i) homogeneous carbon slit pores of widths between 1nm and 4nm and (ii) heterogeneous MOF pores. We discuss the mechanism of layering transition, melting and capillary condensation in subcritical conditions, for temperatures between 80 K and 180 K. The mechanism of layer formation is strongly temperature dependent. At the same time, a commensurability between the methane and the pore sizes is important factor. In slit pores it evolves from a sharp layers formation at 80 K to continuous adsorption at higher temperatures. The capillary condensation is observed clearly in slit pores bigger than 2 nm. The melting transition of methane in slit pores shows complicated mechanism where the interior of the pore melts at lower temperature than the layers adsorbed closer the pore wall. We compare this behavior with the mechanism of adsorption in MOF porous structures where the adsorbing walls are strongly heterogeneous both structurally and energetically. The comparison between the slit pores and the MOFs will allow us to discuss an influence of the heterogeneous wall topology and intermolecular interactions on the thermodynamic properties of nano-confined structures.

The world is running out of fossil fuels and the products of their burning in air (mostly CO2) have already impacted global climate. Therefore, we still need a lot effort to search how to convert the global energy economy towards cleaner and renewable fuels (like hydrogen), in particular, for mobile applications. It is clear now, that to efficiently store hydrogen at ambient temperature and not too high pressures, we need to develop hydrogen sorbent and optimize simultaneously both its specific surface and adsorption energy. In this project we propose to explore the potential effectiveness of arc-discharge procedure to synthetize nanoporous, carbon based sorbents with characteristics required in vehicular applications. The technique was successfully used in the past to synthetize fullerenes and nanotubes. Therefore we have assumed that we can adjust the synthesis parameters to prepare other graphene-based structures, with a variety graphene fragment sizes, forms, and interconnections between them. In addition, arc-discharge technique provides a relatively easy way to incorporate heteroatoms into pure carbon structures.The first characterizations of boron-substituted carbons obtained by this method are promising: the energy of hydrogen adsorption is the highest ever observed experimentally in carbon-based sorbents. However, the specific surface is relatively low, ~ 200 m2/g, suggesting that the samples need to be activated to increase their accessible for adsorption surface and, in consequence, their capacity to store hydrogen.

We study the intrinsic Raman signatures of single layer graphene (SLG) dispersed in degassed water without additives, so called ‘‘eau de graphene” (EdG) and compare them to those of suspended SLG. The Raman signatures of SLG superimpose to those of water. The most characteristic signature of SLG in EdG is a narrow and symmetric 2D band with a width depending on processing conditions. The position of the G and 2D bands indicate moderate biaxial compressive strain and weak n doping. The intensity of the D band and the width of the G band are discussed in terms of point-defect density and flake size. We show that point defects can be easily cured by preparing thin films from EdG and annealing at 800°C.

Curing kinetics of an industrially important printedcircuitboard (PCB) base material (epoxy–phenol/glass fillers)were studied by isothermal differential scanning calorimetry(DSC) measurements between 150 and 190°C, as relevant curingtemperatures for the PCB industry. The extent of cure was calculatedby integration of the exothermic peak and normalizationby the total heat of reaction (obtained by nonisothermal DSC).Although the cross-linking was completed above 180°C, thekinetic profiles show two regimes: one fast and one slow. Thekinetic parameters have been elucidated using an isoconversionalmodel-free kinetic method, with the exact method of Friedman,to give to the PCB manufacturers a road map to predict curingbehavior of base material. The linearity of Arrhenius plots wassatisfactory. The apparent activation energy of curing reactionhas been found to increase with the degree of conversion. Theelucidation of the kinetic parameters allows us to propose anaccurate and predictive description of the curing kinetics withinthe fast regimen of reaction (i.e., without vitrification). Finally,we discuss how these kinetic measurements and models can becompleted and optimized.