The scientific activity of DMC started, in the 1990s, in the field of elementary chemistry processes in the gas phase, with a particular emphasis on the characterization of nature and role of interatomic and intermolecular forces and stereodynamics of molecular collisions by molecular beam experiments and by semi-empirical modeling. Highlights in this topic are well illustrated by highly cited papers (Nature 1994; J Am. Chem. Soc. 1999; Chem. Phys. 2006). Lately, he has been interested in the study of surface physics (see, for instance, Angew.Chemie, 2006; Prog. Surf. Science, 2008) and hydrogen bonded systems (i.e., Acc. of Chem. Res., 2012). More recently, he turned his attention on environmental chemistry and in particular on atmospheric aerosols research (i.e. Atmos. Environ. 2012; ACP2014) and Polar research (i.e. Atmos. Environ., 2015, ACP2016). On these topics, he has been invited to give more than 40 talks at International Conferences and Universities. Research in the Cappelletti group is based on the chemical and morphological characterization of atmospheric aerosols in the urban, remote and indoor environments, vertical profile measurements of aerosol properties by tethered balloon experiments and aerosol source apportionment methodologies, implementation and optimization of chemical transport models (Lagrangian and Eulerian).