Knowledge and understanding:
The course aims to give the students the theoretical tools necessary to determine some important micro- and nano-structural characteristics of complex systems by means of low field nuclear magnetic resonance, cryoporosimetry, mass transport and Rheology.
Applying knowledge and understanding:
The provided theoretical backgrounds enable students to successfully interpret the experimental results, in order to optimize the system/problem under study. In addition, the use of spreadsheets allows the practical application of the theoretical tools presented during the course, enabling also to acquire the necessary physical sensitivity to the magnitudes involved in the systems examined.
Making judgements:
Being able to select the most appropriate strategy to characterize the micro/nano structure of a complex system.
Communication skills:
Being able to expose, by means of a written, oral and graphical exposition, the results coming from the study of a complex system.
Learning skills:
Being able to get from scientific literature, manuals, textbooks and internet, the information (such as materials properties) required to correctly characterize complex systems.

Basic knowledge: transport phenomena.
Didactic: Those required by the Three Years Course on Industrial Engineering, process/materials curricula

The course, starting from the study of complex systems such as polymer matrices, fractal media and living tissues (gastrointestinal mucosa and skin), provides the thermodynamic and kinetics background necessary to interpret the results coming from the use of some micro and nano-structural characterization techniques of the aforementioned systems. In particular, attention is focused on the use of low-field nuclear magnetic resonance, cryoporosimetry, mass transport and Rheology. The course material is given to the student at the beginning of the course

1) M. Grassi, G. Grassi, R. Lapasin, I. Colombo. “Understanding drug release and absorption mechanisms: a physical and mathematical approach”. 2007. CRC Press, Boca Raton, London, New York.
2) Dealy J. M., Wissbrun, K. F. “Melt Rheology and its role in plastics processing”, 1999, Kluwer Academic Publishers, Dordrecht, The Netherlands.
3) M. Guadalupe Puia, Caratterizzazione strutturale di idrogel polimerici per applicazioni biotecnologiche, Dipartimento di Ingegneria Chimica, dell’Ambiente e delle Materie Prime, Università degli Studi Trieste, AA 2007-2008.
4) G. Tesei, NMR a basso campo per la determinazione delle caratteristiche nanostrutturali di matrici polimeriche, tesi di Laurea, Dipartimento di Ingegneria Industriale e dell’Informazione, Università degli Studi di Trieste, AA 2010-2011.
5) S. M. Fiorentino, Structural characterization of polymeric matrices for biomedical applications, XXVII Ciclo di Dottorato di ricerca in scienze chimiche e tecnologie farmaceutiche, Università degli Studi di Trieste, AA 2014-2015.
6) M. Abrami, Biomedical gels: structure and properties, XXIX Ciclo di Dottorato in Molecular Biomedicine, Università degli Studi di Trieste, AA 2016-2017.
7) Course slides (pptx), lessons recordings and course notes (pdf).

1) Complex systems
Polymeric gels, dispersed systems, living tissues, fractal mediums
2) Thermodynamic concepts
Physical equilibrium condition in a system consisting of j phases and k elements
Degrees of freedom of the system and Gibbs-Duhem equation
Thermodynamic potentials
Vapor-Liquid, Liquid-Liquid and Solid-Liquid balance
3) Thermodynamics of the interfaces
Interface, interfacial energy, equilibrium condition
Gibbs-Duhem equation for the interface
Young's equation, wettability, heterogeneous surfaces
Cassie-Buxter equation
Contact angle
Determination of surface energy (eq. State and methods of components)
Wettability (immersion work, adhesion, cohesion, spreading coefficient)
Dissolution and wettability
Determination of the interfacial composition (2 and 3 components)
4) Rheology
Recall of the main rheological properties
Shear stress and strain, Normal stress and strain
Elasticity (Hooke), viscosity (Newton), viscoelasticity, thixotropy - antithissotropy,
Deformation and stress tensor
Deformation and strain rate tensor, definition
Linear viscoelasticity
Boltzmann superposition principle, shear modulus
Viscoelastic models: Hooke, Newton, Maxwell, Voigt, (creep-recovery and relaxation)
Generalized Maxwell model: creep - recovery and stress/strain sinusoidal deformation (expression of the shear modulus, elastic modulus and viscous modulus)
Small sinusoidal stress, Time-temperature superposition principle,
Description of a stress controlled rheometer
Rheological characterization of a gel: stress sweep, frequency sweep, generalized Maxwell model, determination of mesh size by Flory and Schurz theory.
Notes on nonlinear viscoelasticity.
5) Low field NMR
Physical principle of nuclear magnetic resonance
The relaxation time of the spins (T2, T1): CPMG sequence
Effect of solid surfaces on T2: porous and fibrous systems
Estimate of the mesh size distribution of fibrous systems (Chui and Scherer theories)
Relaxation in the presence of a magnetic field gradient: Diffusion coefficient (Latour equation).
Pore size distribution estimate of porous systems.
Determination of the continuous relaxation spectrum
6) Cryoporosimetry
Melting temperature and crystal size
Young equation and Tolmann equation
Spherical and cylindrical pores (Brun's approach and Zhang's equation)
Pore size distribution estimate of porous or fibrous systems
7) Mass Transportation
Call to mass balance
Estimate of the diffusion coefficient for complex molecules
Diffusion coefficient measurement
Determination of the mesh size from release tests
Modeling of release kinetics
Diffusion modeling in fractal media (percolative lattices)
8) Controlled-release pharmaceutical systems
Pharmaceutical systems with controlled release
Absorption mechanisms of the active ingredients (intestine and skin)
Solubility and nanocrystals
Mechanochemical activation
9) Gels
Structure
Swelling equilbrium
Beyond Flory's theory

Frontal lessons
After the explanation of the physics of the illustrated phenomenon, it follows its translation according to the mathematical language for the realization of a model. Finally, students are provided with digital tools (typically software written by the teacher, but not only) which allow the mathematical model to be operational, i.e. they allow the simulation of the described phenomenon in order to realize a close connection between the theoretical and the practical aspects. Many case studies referring to the teacher research and industrial work are presented and discussed to stimulate student sand confer them the so called "forma mentis" typical of engineers.

The final examination comprehends an oral test dealing with all the topics discussed in the course. The student will have to demonstrate that she/he is able to know the physics of the topics covered and their mathematical modeling.
The score of the exam is attributed by means of a vote expressed out of thirty. To pass the exam (18/30) the student must demonstrate that she/he has understood the physical aspects of the topics covered by correctly answering 3 questions using technically and scientifically sound language. To achieve the maximum score (30/30 cum laude), the student must also be able to give a correct mathematical translation of all the physical phenomena requested.

This course is connected to targets 3 and 9