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The development of new anticounterfeiting solutions is a constant challenge and involves several research fields. Much interest is currently devoted to systems that are impossible to clone, based on the physical unclonable function (PUF) paradigm. In this work, a new strategy based on electrospinning and electrospraying of dye-doped polymeric materials is presented for the manufacturing of flexible free-standing films that embed simultaneously different PUF keys. The proposed films can be used to fabricate novel anticounterfeiting labels having three encryption levels: (i) a map of fluorescent polymer droplets, with random positions on a dense yarn of polymer nanofibers, (ii) a characteristic fluorescence spectrum for each label, and (iii) the unique speckle patterns that every label produces when illuminated with coherent laser light shaped in different wavefronts. The intrinsic uniqueness introduced by the manufacturing process encodes enough complexity into the optical anticounterfeiting tag to generate thousands of cryptographic keys. The simple and cheap fabrication process as well as multilevel authentication makes such colored polymeric unclonable tags a practical solution in the secure protection of goods in our daily life.

Functionalized porous silica materials were synthesized in alkaline conditions by post-grafting method using hexadecyltrimethylammonium bromide (CTAB) as templating agent, tetraethyl orthosilicate (TEOS) as silica precursors and trialkoxysilanes functionalised with different organic groups. Textural features, halfway between microporosity and mesoporosity, combined with the surface physico-chemical ones related to various organic groups, determined different CO2storage properties highlighting a strong interaction with the precursor 3-Aminopropyl)triethoxysilane. NMR spectroscopy also showed how physisorption is the mainstream mechanism for CO2adsorption in all the sorbents, except for the aforementioned organic group in which an important chemisorption contribution occurs. Diffusion and molecular mobility analysis revealed that at least two species coexist within the micro-/meso-pores of the sorbents, namely, CO2molecules powerfully interacting with the pore surface (pore-surface CO2) and “bulk-like” CO2filling the central region of the pores. Furthermore, the post functionalization suppresses the diffusion of CO2molecules through the pore channels with all the functionalized materials exhibiting a single self-diffusion coefficient. On the other side, D// strictly depends on the average pore size of the sorbent.

The production of activated carbons (ACs) starting from economic precursors using eco-sustainable synthesis processes appears to be a particularly interesting research field. A possible application can be represented by the use of waste materials to produce ACs through synthesis processes with a low environmental impact for hydrogen (H2) storage. In this work, ACs were produced starting from peach pits, through two processes, i.e., carbonization and physical activation of the raw material. The key process parameters (gas type and temperature) and the starting form of biomass were modified to evaluate their influence on the structural properties and, consequently, the H2adsorption capacity. The chemical and morphological properties of the ACs were investigated through different analyses (energy-dispersive X-ray, EDX; X-ray diffraction, XRD; Fourier-transform infrared spectroscopy, FTIR; scanning electron microscopy, SEM), while textural features and adsorption capacities were determined using a volumetric apparatus. Optimization of the synthesis process allowed us to obtain ACs with a highly microporous structure (≃85%), a specific surface area of around 1317 m2/g, a total pore volume of 0.60 cm3/g, an excellent H2adsorption capacity at low pressure (1.85 wt % at 77 K up to 1 bar), an interesting H2adsorption capacity at high pressure (3.45 wt % at 77 K up to 80 bar), and an excellent cyclicality of storage processes but reduced storage capacity at room temperature (0.28 wt % up to 80 bar).

The methane adsorption properties of activated carbon samples from pinecones using chemical activation with different KOH/precursor ratio were estimated at room temperature (≅298 K) and pressure up to 35 bar using a volumetric Sievert-type apparatus. A complete and detailed characterization of the synthesized activated carbon samples was obtained using nitrogen adsorption/desorption measurements at liquid nitrogen temperature (77 K), for the textural properties analysis, by scanning electron microscopy and X-ray diffraction for topography and long-range order estimation, and by wavelenght-dispersive spectrometry for chemical composition, respectively. All the adsorption data were analyzed by the Tóth isotherm model. The probed activated carbon samples show both higher methane storage values for pressures up to 35 bar (the maximum value reached is 15 wt%) and totally reversible methane uptake up to many cycles without any treatment in between indication of very stable properties. The experimental work reported in this paper could represent a good alternative method to the natural gas storage through the use of eco-compatible nanostructured materials.