PIB derivatives such as PIBSAs and the corresponding PIBSIs characterized by different contents of functional groups were prepared. They showed luminescence both in their neat form and in heptane solution when the amount of functional groups per polymer chain was higher than a critical value. This behavior is attributed to aggregation-induced emission, a phenomenon caused by the aggregation of non-emissive chromophoric carbonyl groups present on PIB derivatives. AIE was studied in heptane solution as a function of the type (SAs or succinimides) and number of interacting functional groups. The results suggest that fluorescence measurements might be an effective tool to determine the degree of functionalization of PIB derivative

The features of molecular structure of seven n-C7 asphaltenes isolated from different feedstocks (i.e., vacuum residue, atmospheric residue and crude oil) have been investigated by pyrolysisgas chromatography/mass spectrometry (Py-GC/MS), and their average structural parameters have been estimated using a mathematical optimization method. The results of structural analysis pointed out substantial differences among the asphaltenes investigated. The size of aromatic fused ring systems ranged from 5.1 to 14.9, while a substantial fraction of peripheral carbon in hydroaromatic/aromatic sheets (0.28-0.40) is substituted with aliphatic chains whose average length was between 2.8 and 6.3. A significant fraction of aliphatic moiety (0.15-0.48) was found to be present as naphthenic structures. In all cases, the main classes of compounds identified during pyrolysis tests were homologous series of alkanes (up to C 25-30 ), 1-alkenes (up to C 25-30 ), branched paraffins, and alkyl-substituted aromatic compounds. The formation of pyrolysis products was explained on the basis of literature data regarding thermolysis reactions of model compounds mimicking the structural features of asphaltenes. The results of this study are consistent with the view that asphaltenes are a complex polydisperse mixture of molecules made up of polyaromatic and hydroaromatic units joined by aliphatic bridges and substituted with aliphatic chains containing up to 25-30 carbon atoms. However, both NMR data and results of structural analysis indicate that the major part of these chains (more than 80%) is formed by short alkyl groups (C1-C4).

In this work, the thermal Alder-ene functionalization of highly reactive, vinylidene-terminated, polyisobutene (PIB) with\ud stoichiometric amounts of maleic anhydride at 200 ◦C was investigated by NMR spectroscopy. The thorough interpretation of\ud the complex NMR spectra of PIB derivatives collected at different reaction times (from 4 to 21 h) was based on the combined\ud use of one- and two-dimensional techniques which allowed the precise structure of all the reaction products as well as their\ud relative content to be ascertained. The analysis evidenced the formation of large amounts of derivatives generated by the\ud classic Alder-ene mechanism and involving the more reactive vinylidene ‘exo’ double bonds of PIB. More interestingly, the\ud investigation also the investigation allowed also to detect the formation of a noteworthy amount of not expected structure\ud generated by the thermalmaleination of the less reactive PIB ‘endo’ β-form provided by the isomerization of residual PIB ‘exo’ α-form during the functionalization reaction

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Humic acids from difgferent origin/source have been characterised, particularly by using spectroscopic technique

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This paper reports on a detailed physical–chemical characterization of different carbonaceous particulates (commercial carbon blacks and diesel engine-derived soot) by using a combination of several techniques such as scanning electron microscopy (SEM), absorption isotherms, infrared spectroscopy, and small angle X-ray scattering (SAXS), to provide information on the chemical composition and structure at the micro- and nanoscale level. SEM micrographs indicate an almost spherical primary unit for all investigated samples with a diameter ranging from 5 to 100 nm. On the other hand, SAXS allows extracting the fractal dimension of both the primary units and the aggregates. All these results, taken together, can be used as a reference point to define an appropriate and rather cheap commercial surrogate for engine-derived soot and, alternatively, to choose the better carbon black according to the final industrial application.

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