Foto del docente

Marco Giacinti Baschetti

Associate Professor

Department of Civil, Chemical, Environmental, and Materials Engineering

Academic discipline: ING-IND/24 Fundamentals of Chemical Engineering

Research

Keywords: Permeability Diffusivity Solubility Ceramic membranes Glassy Polymer

The different topics currently considered in the research activity are mainly related to the study sorption, diffusion and permeation of gases and vapors in different materials and to the other phenomena, such as swelling or modification of physicochemical properties, that are to these processes.

The different research topics can be summarized as follows:

-    Study of diffusion sorption and of organic vapors in glassy polymers with particular attention to those endowed with very high free volume such as poly(1-trimethylsilyl-1-propyne)

-    Permeability measurements on different nanocomposite and barrier materials to water vapor nitrogen and oxygen to test their potential use in the food packaging industry

-    Fabrication and testing of Pd-Ag based membrane for hydrogen purification

-    Study of water and methanol diffusion in perfluorosulfonated materials as proton exchange membrantop be used in fuel cell systems



A brief overview of the different research activities of Dr. Giacinti Baschetti is reported below. For a more complete description the reader can refer to the bibliography section.

Characterization and modelling of Perfluorosulphonate ionomeric materials for fuel cells applications.

 The study of perfluorosulphonated ionomeric (PFSI) materials to be used inside Proton exchange membranes Fuel cells (PEM-FCs), is a research field which started within a collaboration with Ausimont S.p.A in years 2000 and it is still one of the most active research field for the diffusion in polymer group of the University of Bologna.

Dr. Giacinti Baschetti's interest in particular is focused on the study of the mass transport properties of Aquivion® (formerly known as Hyflon Ion®) a new short side chain PFSI material, produced by Solvay-Solexis, that could be used as PEM inside a fuel cells having good proton conductivity and higher mechanical resistance with respect to Nafion®, the benchmark material for these kind of applications. During the experimental work which covered more than five years of activity, the water and methanol sorption and permeation in extruded as well as cast films of Aquivion® were measured with different experimental techniques and in different experimental conditions allowing to confirm the similarities with Nafion for extruded membranes and the need for a better production protocols for cast films which showed lower water absorption with respect to extruded ones. The experimental work was accompanied also by a modelling activity which allowed to describe in a quantitative manner the process of water sorption in Aquivion® through a diffusion reaction model, which then proved to be suitable also for Nafion® membranes.

 Membranes and membrane separation processes for hydrogen purification

 Another very active research field for Dr. Giacinti Baschetti was, in the last years, the one related to the study of palladium membranes for purification of hydrogen produced through methane reforming, which was conducted in the framework of an Italian project started in 2005 and then continued as an activity sponsored by the Interdepartmental Centres for Industrial Research (CIRI) of the University of Bologna. To carry out the different activities Dr. Giacinti Baschetti and his colleagues set up a new experimental apparatus for the measurements of permeability of different gases in Pd-based membranes in different experimental conditions and characterized different Pd and Pd-Ag membranes both produced inside the research group or supplied by other partners. The activity was focused not only on membranes characterization but also on the modelling of the permeation process, with particular attention to the influence of gas phase resistance and palladium poisoning on the membrane module efficiency. In particular the modelling work allowed to develop mathematical tools able to account for both these effects starting from a sound theoretical approach and without the use of simplified or empirical correlations which are sometimes used for this purpose. Moreover a numerical model based on a computational fluid-dynamics approach was also developed which could be of great help in the design and scale up of Pd based membrane separation modules for these kind of applications.

Even if it has not produced any publication yet, it is worthwhile also to mention that in the very last years a research has started also in the field polymeric membranes for purification of hydrogen produced through bio-chemical reactions inside an Italian project in which Dr. Giacinti Baschetti is coordinating the activity of the membrane separation working group.  

 Analysis of diffusion in nanocomposites and barrier materials for packaging applications

 The attention to barrier materials for packaging applications has been one of the interest of Dr. Giacinti Baschetti since his participation to a national research project related to clay based nanocomposites materials in 2004, and to the Sustainpack project founded in the EU FP6. The work was once again focused both on experimental and modelling activity. In particular the experiments were focused on the characterization of permeability of innovative films based on microfibrillated cellulose (MFC) which showed extremely interesting barrier properties, comparable with those of oil based non biodegradable materials such as PET. The water solubility as well a water and oxygen permeability of these films were measured confirming the interesting properties of MFC but also their sensitivity to water which caused a permeability increase of more than two order of magnitude in pure MFC membranes.

The modelling was instead related to the analysis of transport properties of clay based nanocomposite. Diffusion in these materials was indeed modelled by considering a numerical approach which allows to describe the behaviour of gas diffusing in heterogeneous systems where impermeable flakes are dispersed in a permeable matrix. This approach gave consistent results for ordered systems, for which an analytical solution exists, and also allowed to obtain guidelines for the prediction of permeability in disordered systems, where the clay platelets are randomly distributed in the polymeric matrix. 

In the last years the involvement in two COST Actions and in a Marie Curie Training network, where Dr. Giacinti acts as training coordinator, gave new force to this research field which among the other results allowed to develop a new method for depositing MFC coatings on hydrophobic biopolymers such as Polylactid Acid which is now being patented by the University of Bologna.

Analysis of sorption and diffusion in Glassy polymers and other complex systems

 The interest on mass transport properties of complex materials, such as non equilibrium glassy polymers, nanocomposites or phase segregated block-copolymers, has accompanied Dr. Giacinti Baschetti from the beginning of his research activity. Apart from the already considered research on PSFI and nanocomposites, indeed he also worked on a number of other systems and research activities which are briefly described below:

- Polytrimethylsilylpropyne (PTMSP), alone or combined Polytrimethylsilylhexine to form block-copolymers was studied in order to describe and understand the peculiar transport properties of this materials. In particular the determination of solubility, diffusivity of different vapors in both materials was considered focusing the attention on the analysis of the effect of ageing, which resulted more pronounced for PTMSP homo-polymer with respect to block-copolymers, that were endowed with lower free volume and permeability but were characterized by higher long term stability. On PTMSP also a modelling analysis was considered to find an explanation of the deviation from solution diffusion permeation mechanism sometimes observed for this material. In particular Dr. Giacinti Baschetti developed a numerical approach for the description of the diffusion of this nanoporous material which was considered as a web of semi interconnected voids channel constituting a preferential pathway for diffusion of penetrant molecules.

- Apart from high free volume systems, the interest on glassy polymers has always been present in the research activities of Dr. Giacinti Baschetti in view of the modelling of solubility in these materials through the use of a non-equilibrium approach developed inside the Diffusion in polymers research group. The Non Equilibrium Thermodynamics for Glassy polymers (NET-GP) approach indeed that was initially elaborated by Profssor Sarti and Doghieri and then extended, applied and adapted, also with contribution of Dr. Giacinti Baschetti, to different systems, such as biopolymers, polymer blends and penetrants inducing not negligible polymer swelling.

- Related to the previous activity also the analysis and the measurement of polymer dilation upon sorption has been an active field of investigation; NET-GP approach indeed needs polymer density to be known during sorption for a complete prediction of the system behaviour. As a consequence the experimental measurements of sorption induced polymer swelling was one of the other interests of Dr. Giacinti Baschetti who, during its career at University of Bologna, contributed to the set up of al least three different apparatuses which could give contemporary information on sorption and swelling processes in the polymer-penetrant system. One of this experimental systems in particular exploited the technique of Attenuated total reflectance Fourier transport infrared spectroscopy (FTIR-ATR) with which he learned during his stay at Johns Hopkins University in Baltimore.

- Dr. Giacinti Baschetti also worked with block copolymer which included the analysis rheological and transport properties of phase segregated diene-styrene based block copolymers, made in collaboration with Polimerieuropa a National company leader in the production of elastomeric materials, as well as the analysis of sorption and diffusion behaviour of homogeneous but semicrystalline poly(ethylene-co-octene)s which was carried out while tutoring a PhD student in secondment from the Royal Institute of Technology (KTH) in Stockholm, Sweden, and, more recently, the analysis of transport behaviour of semi-crystalline polystyrene-block-poly(ethylene oxide) copolymers to be used as solid electrolytes in lithium batteries and potentially interesting also for CO2 recovery from gaseous streams.