Clar Sextet Analysis of Triangular, Rectangular and Honeycomb Graphene Antidot Lattices

Pristine graphene is a semimetal and thus does not have a band gap. By making a nanometer scale periodic array of holes in the graphene sheet a band gap may form; the size of the gap is controllable by adjusting the parameters of the lattice. The hole diameter, hole geometry, lattice geometry and the separation of the holes are parameters that all play an important role in determining the size of the band gap, which, for technological applications, should be at least of the order of tenths of an eV. We investigate four different hole configurations: the rectangular, the triangular, the rotated triangular and the honeycomb lattice. It is found that the lattice geometry plays a crucial role for size of the band gap: the triangular arrangement displays always a sizable gap, while for the other types only particular hole separations lead to a large gap. This observation is explained using Clar sextet theory, and we find that a sufficient condition for a large gap is that the number of sextets exceeds one third of the total number of hexagons in the unit cell. Furthermore, we investigate non-isosceles triangular structures to probe the sensitivity of the gap in triangular lattices to small changes in geometry

Leather-based fertilizers from Personal Protective Equipment (PPE) reverse logistics: Technical efficiency and environmental safety.

Agriculture and industry are seeking healthy food and enough goods to meet the global demand without causing environmental impacts, which motivates the search for sustainable and eco-efficient technologies. This study focuses on reverse logistics in the Personal Protective Equipment (PPE) industry. Chrome-tanned leather shavings from the manufacture of PPE and post-use leather PPE were used to produce leather-based fertilizers (LBFs), which were evaluated for their agronomic efficiency and food safety. N-rich liquid LBFs were successfully produced through hydrolysis, either with or without previous chromium extraction. At the dose of maximum technical efficiency, LBFs are safe, with acceptable levels of Cr in the plant biomass and the soil compartments. However, LBF overdoses promote Cr accumulation in plants and soils, which demonstrates the need for a rigorous control over the fertilization management to ensure successful PPE reverse logistics

The thiophene-based inherently chiral monomer family grows: molecular design and electrochemical properties

Our group has recently presented electroactive thiophenebased polyconjugated films of unprecedented chirality manifestations and enantiorecognition ability,[1] based on the "inherent chirality" concept, implying that the whole electroactive backbone coincides with the stereogenic element, consisting in a tailored torsion induced by an atropisomeric bi-benzothiophene scaffold. Such films are easily prepared as enantiopure electrode surfaces by electrooligomerization of (R) and (S) enantiopure monomer 1. Now, concurrently with the exploration of the applicative potentialities of this "parent" molecular material, both racemic and enantiopure, we are widening the class of available monomers designed according the same strategy, but with different atropisomeric heteroaromatic scaffolds, different side chains, and/or with the addition of a further stereogenic element. The electrochemical properties of a selection of the new inherently chiral monomers now available will be presented in detail and rationalized as a function of their molecular structure, also in the perspective of potential applications. With the contribution of Fondazione Cariplo, grant no. 2011-0417. [1] F. Sannicol\uf2, S. Arnaboldi, T. Benincori, V. Bonometti, R. Cirilli, L. Dunsch, W. Kutner, G. Longhi, P.R. Mussini, M. Panigati, M. Pierini, S. Rizzo, Angew. Chemie 2014, 53, 2623-2627