The field of ion transport through carbon nanotubes (CNTs) is marked by a large variability of the ionic conductance values reported by different groups. There is also a large uncertainty concerning the relative contributions of channel and access resistances in the experimentally measured currents, both depending on experimental parameters (nanotube length and diameter). In this perspective article, we discuss the ionic conductance values reported so far in the case of 2 individual CNTs and compare them with standard nano-fluidic models considering both the access and channel resistances. With a view toward guiding experimentalists, we thus show in which conditions the access or the channel resistance can predominate in CNTs. We explain in particular that it is not justified to use phenomenological models neglecting the channel resistance in the case of micrometer-long CNTs. This comparison reveals that most experimental conductance values can be explained in the framework of current nanofluidic models by considering experimental variations of slip length and surface charge density and that just a few extraordinarily high values cannot be accounted for even using extreme parameter values. Finally, we discuss how to complete existing models and how to improve the statistical reliability of experimental data in the field.

Aim of investigation is to study the possibility of activating a promising Ni(OH)2, prepared using two-step high-temperature synthesis, by adding 3%, 5% and 10% (mol.) Al3+ to Ni2+. For describing the intercalation of Al3+ into hydroxide structure, "Separate-Solid—Liquid—Solid" mechanism, which included the formation of separate Al-containing phase on synthesis stage, and incorporation of Al3+ into Ni(OH)2 or formation of surface compounds during hydrolysis stage, has been proposed. EDX analysis of precursor confirmed the formation of separate Al-containing phases. By means of PXRD, EDX, SEM, TEM revealed realization of both ways of Al3+ incorporation: at high amounts of Al3+ (5% and 10% mol.), predominantly surface compounds are formed with distorted and altered particle shape and appearance of "core–shell" particles. At low amounts of Al3+ (3% mol.), permeably doping occurs, with partial intercalation of Al3+ into the nickel hydroxide structure. Based on CVA and GCDC results, Al3+ acts as a poison upon the formation of surface compounds have been found. Upon doping of hot hydrolysis samples with aluminum, sample activation was observed, which resulted in an increase of specific capacity by 1.99 times, from 569 Fg−1 (pure Ni(OH)2) to 1112 Fg−1.

The current challenge is to produce asphalt mixtures incorporating higher rates (>50%) of Re-claimed Asphalt (RA) while controlling the quality of the final mix. During the service life of a pavement properties change, mainly due to oxidation and need to be restored. The resulting mix must exhibit at least equivalent performances regarding the mechanical and durability properties compared to that from a mix without RA. Hence, recycling agents are sometimes employed to “rejuvenate” aged bitumen. In this study, three recycling agents were used on both RA and neat bitumens, displaying different compositions. The effects on unaged and aged blends were as-sessed through rheology tests using Dynamic Shear (DSR) and Bending Beam (BBR) Rheome-ters. Data from DSR obtained with 4mm and 8mm parallel plates allowed to calculate the Glov-er-Rowe criteria and to determine the crossover parameters whilst BBR measurements yield Tm, Ts and ΔTc parameters. The blends resulting from the two bitumens displayed a similar evolu-tion of behavior. This outcome suggests that these tests cannot discriminate the origin of the re-juvenation phenomenon since they only highlight the softening effect of the recycling agent and not its impact at the molecular level, i.e. on asphaltene and maltene compounds.

We present experimental and theoretical results on the electrical conductivity and other properties of carbon nanotubes.