The complexity of the odours issue arises from the sensory nature of smell. From the evolutionary point of view olfaction is one of the oldest senses, allowing for seeking food, recognizing danger or communication: human olfaction is a protective sense as it allows the detection of potential illnesses or infections by taking into account the odour pleasantness/unpleasantness. Odours are mixtures of light and small molecules that, coming in contact with various human sensory systems, also at very low concentrations in the inhaled air, are able to stimulate an anatomical response: the experienced perception is the odour. Odour assessment is a key point in some industrial production processes (i.e., food, beverages, etc.) and it is acquiring steady importance in unusual technological fields (i.e., indoor air quality); this issue mainly concerns the environmental impact of various industrial activities (i.e., tanneries, refineries, slaughterhouses, distilleries, civil and industrial wastewater treatment plants, landfills and composting plants) as sources of olfactory nuisances, the top air pollution complaint. Although the human olfactory system is still regarded as the most important and effective “analytical instrument” for odour evaluation, the demand for more objective analytical methods, along with the discovery of materials with chemo-electronic properties, has boosted the development of sensor-based machine olfaction potentially imitating the biological system. This review examines the state of the art of both human and instrumental sensing currently used for the detection of odours. The olfactometric techniques employing a panel of trained experts are discussed and the strong and weak points of odour assessment through human detection are highlighted. The main features and the working principles of modern electronic noses (E-Noses) are then described, focusing on their better performances for environmental analysis. Odour emission monitoring carried out through both the techniques is finally reviewed in order to show the complementary responses of human and instrumental sensing.

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The thin film deposition in DBDs fed with Ar/HMDSO/O2 mixtures was studied by comparing the FT‐IR spectra of the deposits with the GC‐MS analyses of the exhaust gas. Under the experimental conditions investigated, oxygen addition does not enhance the activation of the monomer while it highly influences the chemical composition and structure of the deposited coating as well as the quali‐quantitative distribution of by‐products in the exhaust. Without oxygen addition a coating with high monomer structure retention is obtained and the exhaust contains several by‐products such as silanes, silanols, and linear and cyclic siloxanes. The dimethylsiloxane unit seems to be the most important building block of oligomers. Oxygen addition to the feed is responsible for an intense reduction of the organic character of the coating as well as for a steep decrease, below the quantification limit, of the concentration of all by‐products except silanols. Some evidences induce to claim that the silanol groups contained in the deposits are formed through heterogeneous (plasma‐surface) reactions.

This work describes the plasma‐enhanced chemical vapor deposition of thin films at atmospheric pressure using dielectric barrier discharges fed with argon, oxygen and different methyldisiloxanes, i.e., hexamethyldisiloxane, pentamethyldisiloxane, and 1,1,3,3‐tetramethyldisiloxane. The influence of the methyldisiloxane chemical structure and of the oxygen/methyldisiloxane feed ratio is investigated in order to provide insights into the organosilicon plasma chemistry at atmospheric pressure. As expected the FT‐IR and XPS analyses show that the carbon content of the coatings depends on the number of methyl groups in the precursor molecule; in the case of coatings obtained with PMDSO and TMDSO carbon removal seems to be further enhanced by the presence of SiH bonds. Gaschromatography‐mass spectrometry analyses of the exhaust gas allow to assess the precursor depletion and to perform the quali‐quantitative determination of by‐products (e.g., silanes, siloxanes, silanols) formed by plasma activation. The results are exploited to rise hypotheses on the contribution of the different reaction pathways on the deposition mechanism.

The objective of the present work is to develop nanostructured surfaces by combining low pressure plasma process and colloidal lithography, with the aim of obtaining suitable substrates with predetermined ordered nanometric surface roughness and surface chemical composition. The chemical properties of the resulting nanostructures were characterized by means of X‐ray photoelectron spectroscopy (XPS) and water contact angle (WCA) measurements, their morphology was characterized by scanning electron microscopy (SEM). The effects of both chemistry and morphology on Saos‐2 osteoblast cell behavior was investigated.