The course is an introduction to the physical chemistry of finely dispersed systems. These systems are largely adopted in process engineering (environmental remediation, formulation chemistry, synthesis of pigments and catalysts) as well as in the production of different kinds of materials (biomaterials, ceramics, polymers and soft matter). The transformations in the dispersed state are strongly influenced by the high surface energy of the system and their study needs a peculiar approach, capable of linking information from the microscopic structure of the interface and the macroscopic global properties of the dispersion. The course begins with the macroscopic description of the interface provided by surface mechanics and thermodynamics, and subsequently moves towards the aspects related to the smallest scales: surface forces, charge separation and structure of interfaces. Finally, the modes of evolution of a disperse phase are examined and population balance method is introduced, as a tool to predict the dynamics of a disperse system.

The aim of the course is to provide students with the basic knowledge necessary to understand the main phenomena occurring in heterogeneous finely dispersed systems, and to quantitatively predict and control their dynamics. In particular, at the end of the course the student should know the main evolution mechanisms of a dispersion and be able to select proper methods to control or modify the size distribution and the morphology of a disperse phase.

Students should have a good knowledge of the fundamentals of chemistry, physics, thermodynamics, mathematics and numerical methods.

1: Mechanics and thermodynamics of interfaces (15 h) Surface and interfacial tension, Young-Laplace equation, capillary rise, contact angle; surface tension and stress in solids; Kelvin equation and capillary condensation; dynamic effects on surface tension and contact angle. 2. Structure of the solid-liquid interface and electrical double layer (15 h) Mechanisms of surface charge generation; ion distribution and charge distribution; Z potential and electrokinetic phenomena 3: Surface forces in dispersed systems (10 h) Van der Waals forces; Electrical double layer interaction; Electrostatic stabilisation of colloidal dispersions and DLVO theory; Steric stabilisation; Structural forces; Capillary forces. 4. Evolution of a disperse system (20 h) Aggregation-coalescence: kinetics and mechanisms (Brownian, shear flow, turbulent, inertia); Nucleation: primary homogeneous and heterogeneous, secondary; growth and dissolution; Introduction to the population balance approach: characterisation of a population of particles; prediction of the dynamics by the balance equation.

The course is organized in lectures and practical sessions devoted to the solution of simple problems.

Some reference books are listed below. The teachers will suggest the proper bibliography. H.J. Butt, K. Graf, M. Kappl, Physics and Chemistry of Interfaces, Wiley-VCH. J.C. Berg, An Introduction to Interfaces and Colloids: The Bridge to Nanoscience, World Scientific. P.C. Hiemenz, R. Rajagopalan, Principles of Colloid and Surface Chemistry, CRC Press. J.W. Mullin, Crystallization, Butterworth.

Modalitą di esame: Prova orale facoltativa; Prova scritta tramite PC con l'utilizzo della piattaforma di ateneo;

The exam is aimed at ascertaining the knowledge of the subjects listed in the course syllabus and the ability to apply the theory and related calculation methods to practical applications. The written part of the test lasts approximately two hours. It contains short theoretical questions, to ascertain the knowledge of the basic aspects of the subject, and simple numerical problems to verify the ability to quantitatively predict the response of a system. No notes, handouts or books may be kept or consulted during the test. The result of the exam is communicated on the teaching portal, together with the date on which the students can view the test and give the optional oral exam. After the written test, the exam can be concluded (in this case the maximum grade is 27/30) or it can be continued with an additional oral exam, which aims at evaluating in depth the comprehension of the subject and the ability to apply the theoretical results.

Modalitą di esame: Prova scritta (in aula); Prova orale facoltativa; Prova scritta tramite PC con l'utilizzo della piattaforma di ateneo;

The examination consists of a 1.5-hour written test (taken in classroom or remotely) followed by an optional oral test (also either in classroom or remotely). Rules and criteria are fully similar to those of the online exam.