PHYSICAL CHEMISTRY OF NANOTECHNOLOGIES

CHIM/02 - 7 CFU - 2° Semester

Teaching Staff

GIOVANNI MARLETTA

Learning Objectives

The course will provide the physico-chemical bases of nanotechnologies, with special reference to the classes of molecular materials of interest to advanced technologies. Subject of the course are, therefore, the physico-chemical concepts underlying the behavior of complex systems of molecular aggregates, with particular attention to their application at the nanoscale, and the main instruments and methodologies relevant to their study. Learning objectives, then, will involve the acquisition of the ability to relate the main phenomena at nanoscale level to the physico-chemical laws that control them, as well as the ability to understand and choose the appropriate conditions for the use of methodologies, from time to time, better suited to study nanoscale systems, or to obtain their nanostructuring, in view of their functional properties.

Detailed Course Content

1) Introduction to Nanotechnologies – Definition of the field – Criteria to determine nanometric systems and their relevance – 1D, 2D and 3D systems (2 h)

2) Physico-Chemical bases of Nanostructures and related observation techniques (20 ore)

Basics (2 hours): hints of Intermolecular forces and their general characteristics – relationship between binding energies/force/time scales in condensed matter – Hints on the thermodynamic and kinetic order processes – Hierarchy of spatial order.
Mechanical stimuli (4 hours): mechanical quantities for the characterization of viscoelastic systems - Response of condensed phases to applied stresses – Young's modulus - Strain dependence on the stress application rate – Concept of experimental time and relaxation time - Deviations from ideal behavior – Strain energy barriers and Eyring’s "argument" – Viscosity in simple and complex fluids - Molecular models of elasticity and mechanical response - Time scale - Small deformations approximation - Molecular mechanism of stress relaxation.
Radiative Stimuli (2 hours): radiation-matter interaction – evolution of molecular and solid systems under high local densities of energy – etching processes – processes of grafting.
Nucleation and growth mechanisms (3 hours): General characters of liquid-solid transitions – homogeneous and heterogeneous nucleation processes – homogeneous nucleation mechanism –surface/volume terms’ balance – activation energy barrier and critical radius of growth of crystalline particles - Heterogeneous nucleation mechanism – A three-component system: surface and volume terms - Activation energy barrier for heterogeneous processes – Linear and dendritic propagation fronts.
Nanoscopic Processes in polymers (3 hours): Lamellae as hierarchical structures – The energy factors in crystalline order - Selection mechanism of lamellae size - Energy and speed of growth of a crystalline seed – Crystalline growth dependence on temperature - Modes of deformation at constant speed and oscillatory deformation - Linear viscoelasticity and Boltzmann superposition principle - Viscoelasticity dependence on temperature: Relaxation modulus and Williams-Landel-Ferry (WLF) equation – The "entanglement" concept - Entanglement and chain lengths – Chain motion in condensed phase and “creeping” model – Approximations for non-linear behavior.
Electrical properties of molecular systems (6 hours): Basics – Peculiarities of molecular system electrical properties – Electronic structure of molecular condensed phases – macroscopic conductivity and specific conductivity - Electronic structure and conductivity of molecular solids – Nature and mobility of charge carriers - Effective mass, bandwidth and conductivity - Types and generation mechanisms of charge carriers – Intrinsic carriers –"Doping" processes with electron-donors or -acceptors - Polarons, bipolarons and solitons – Chemical "doping" –"Electrochemical doping" and non-redox processes – Photoinduced doping processes - Charge-transfer molecular systems – organic complexes - polymer/molecule complexes –Complexes with transition metal - Polymer/fullerene complexes - Localized states and "trapping" mechanisms – Trapping at order/disorder interfaces – Energy distribution of "trapping states" – Trapping state from conformational "distortions" – Dipoles and "polarons" - Charge injection processes and localized states -Surface states – Contact Phenomena : Fabish–Duke model – Structural factors and "the trapping states" – Mixtures of polymers with different function to work.
3) Nanostructuring methods (6 hours + 6 laboratory): Top-down methods: lithography and nanolitographies - Bottom-up methods: processes of self-organization and self-assembly on surfaces - Langmuir-Blodgett methods - Methods for "soft" nanolithography.
4) near-field Microscopy (6 hours + 6 laboratory): Introduction to Scanning Probe Microscopies (SPM) - Atomic Force Microscopy (AFM) - Scanning Tunneling Microscopy (STM) - Scanning Near-Field Optical Microscopy (SNOM).
5) Nanotechnology and life sciences (4 hours): The nanometric cues for proteins, ECM, cells - Nanometric objects for “in-body” work.
6) Nanotechnology and Nanoelectronics (4 hours): Introduction to nanoelectronic components – Elements of molecular electronics

Textbook Information

Testi di riferimento:

The Course of Physical Chemistry of Nanotechnology is newly created and will be held for the first time in 2016/2017 AA (2nd semester), so that (in the first delivery of the course) Lecture notes and articles from specialized Journals will be made available to students from time to time.

1) Introduction to Nanotechnologies