RESUMO
This work investigates the effects of neutron irradiation on nitrogen and hydrogen adsorption in boron-doped activated carbon. Boron-neutron capture generates an energetic lithium nucleus, helium nucleus, and gamma photons, which can alter the surface and structure of pores in activated carbon. The defects introduced by fission tracks are modeled assuming the slit-shaped pores geometry. Sub-critical nitrogen adsorption shows that nitrogen molecules cannot probe the defects created by fission tracks. Hydrogen adsorption isotherms of irradiated samples indicate higher binding energies compared to their non-irradiated parent samples.
RESUMO
The complex structure of activated carbon can be described as a three-dimensional network of graphene layers oriented in random directions. In this work, we propose a new model of the microporous structure, taking into account the degree of activation. We derive a structural relation between porosity, skeletal density, specific surface area, and the number of graphitic blocks per unit volume. In addition, we present a new approach to evaluate the interdependency between porosity and specific surface area by combining high-resolution scanning transmission electron microscopy and subcritical nitrogen adsorption. Finally, we propose a structural metric that predicts the relation between the volumetric storage capacity and the gravimetric storage capacity of supercritical methane at room temperature.
