Learning objectives
D1 - Knowledge and comprehension skills
The student will be able to describe the fundamental concepts of nanochemistry and how they are applied to the different classes of materials. He will understand the thermodynamic basis of the growth of nanocrystals and the interactions between them. He will be able to describe how the interactions affect the self-assembly of nanocrystals. He will know methods for controlling the size, shape, defects, and surface chemistry of nanostructures, as well as the effect of these parameters on the optical, magnetic, biological, and electrical properties of materials.
D2 - Ability to apply knowledge and understanding
The student will have the ability to draw up one or more synthetic strategies for obtaining a proposed nanostructure. As well as it will have the ability to qualitatively predict how the properties of the material are modified in the nanostructured form. Finally, the student will know which characterization approaches are necessary to validate the success of the synthetic strategies he / she proposes.
D3 - Autonomy of judgment
The student will be able to independently evaluate characterization data that identify fundamental aspects of nanostructured materials (composition, size, shape, crystalline structure). He/she will also be able to identify additional characterizations that may be necessary to uniquely identify a nanostructured material.
D4 - Communication skills
The student will be able to find information and communicate on issues related to nanochemistry.
D5 - Learning skills
The student will be able to obtain and sift information through databases and search engines, and will be able to continue to study the subject of nanochemistry independently.
Prerequisites
Basic knowledge of electromagnetism, thermodynamics, acquired in the three-year degree courses.
Course unit content
Chapter I.
Strength vs Fields vs Potentials vs Potential Energies
State variables
Unit of measure
Energy, pressure, temperature, force, moment, entropy, gas constant
Process variables
Differences between state and process variables
Difference between heat and temperature
Definition of systems (closed, rigid, etc ...)
First law of thermodynamics (microscopic and macroscopic form)
Equations of state (what they are)
Equation of state of ideal gases
Intakes of ideal gases
Reversible vs irreversible processes
Entropy (explained at the microscopic level)
Difference between microstates and macrostates
Free energies and their meaning
Microscopic and macroscopic significance of entropy and enthalpy and how these affect G depending on the temperature.
Maxwell Boltzmann distribution and its meaning
Chapter II
Particle wave duality
Principle of uncertainty as a consequence of the particle wave duality
Orbitals as standing waves in 3D in the presence of an electron-nucleus attractive potential
Classification of orbitals
How the electronic structures of atoms are built
What influences the energy of the orbitals
Energy transitions between orbitals and atomic absorption and emission spectra
Ionization energies (definition and trends on the periodic table)
Electronic affinity (definition and trends on the periodic table)
Atomic radius (definition and trends on the periodic table)
Molecular orbitals (what they are and why they are a valid description of chemical bonds)
Differences between binding and antibonding orbitals
Differences between sigma and pi bonds
Lewis structures and limitations of the valence bond theory
Ionic binding component
Electronegativity (definition and trend on the periodic table)
Number (state) of oxidation
Hybridization sp1, sp2 and sp3
Resonance
Nitric acid and nitrate ion
Coordination bond
Hydrogen bond
Dependence of the bond energy on atomic rays, electronegativity, bond length
Definition of dipole (what influences its value)
Permanent vs temporary dipoles
Van der Waals interactions and what influences them
Different energy of the interactions and how these determine the formation of phases with temperature (and why)
Ketelaar triangle
Covalent compounds, ionic and metallic compounds
How to predict if a substance will be an extended solid or a molecule
Differences between ionic, metallic and covalent solids from the electron point of view
Phases (definition and examples)
Trend of the enthalpy of a phase with the temperature
Trend of the entropy of a phase with temperature
Thermodynamic meaning of the balance between two phases
Latent heat (what it is and where it comes from)
Ideal solutions (assumptions)
Dependence of the ∆G of solution on the composition for ideal solutions
Difference between real and ideal solutions
Model of regular solutions
Partial molar variables
Chemical potential, activity, activity coefficient in real and ideal solutions
Origin of immiscibility
Chapter III
Variance
Affinity, equilibrium constant, reaction quotient, and standard free energy of reaction in monovariant systems
What changes when you have multivariant systems
How to simplify a multivariant system
How to solve a multivariant system
Ellingham diagram (what it shows and what information can I get from it)
Predominance diagrams (what they are and what information they can give me)
Solubility equilibria
Acids and bases according to Arrhenius and Bronsted
"Strength" of acids and bases
Conjugated acids and bases and their influence on their strength
Balance of water dissociation and pH / pOH
Hydrolysis
Chapter IV
Galvanic cell (how it is built, why, and the chemical processes that take place inside it)
Electromotive force
Normal reduction potentials (how they are obtained and what they allow us to calculate)
Electrolytic cells and differences with galvanic cells
Full programme
The course introduces students to chemistry with an interdisciplinary approach. Unlike similar courses for chemists and physicists, the course starts from the physical basics (i.e., interactions and how they are quantified by fields, forces, potentials and potential energies), as well as qualitatively explaining the mathematical tools to understand them. On these bases the thermodynamic basis of chemistry is then introduced both in the Gibbsian macroscopic aspect and in the statistical aspect with the aim of clarifying the microscopic nature of entropy (Boltzmann equation) as well as laying the foundations for a deep understanding of the distribution. by Maxwell Boltzmann on which much of the quantitative description of chemical processes is based.
Once this is done, the course introduces the atom in a qualitative way using as much as possible classical or semiclassical analogies (e.g., waves, spherical harmonics) to explain quantization. The uncertainty principle is introduced as a direct consequence of the wave-particle duality. On this basis it is possible to provide a profound insight into the nature of orbitals without necessarily having to make an analytical treatment that is beyond the reach of first year students.
The orbitals are then used to explain the properties of the atoms and therefore the periodic trends of the periodic table.
Chemical bonds are first dealt with as molecular orbitals and only later with the valence bond theory. This allows students a better understanding of the limitations of more popular chemistry concepts (the octet, the Lewis formula, etc ...).
The chemical bond leads to the description of the concepts of electronegativity, of the Ketelaar triangle. We use nitric acid as a "case history" to introduce the concepts of hybridization, resonance. This, in turn, allows us to introduce the dipole-dipole bonds as well as the hydrogen and dative bonds.
Based on this set of information, we make several examples of predicting the characteristics of the compounds formed as a consequence of the bonds. Therefore, not only in order to predict the formation of molecules instead of extended solids, but also the prediction of the electronic properties of the phase.
After that, the students are introduced to the phases (from gases, made previously) to liquids and solids and how to calculate their stability on the basis of the thermal capacity functions at constant pressure.
Once the phases (and their equilibria on the basis of the equivalence of G (T)) have been explained, the solutions are introduced using the concept of solution energy and therefore the models of ideal and regular solutions. This then naturally leads to the concepts of activity, activity coefficients and chemical potential.
Once this introductory part is completed, students are now ready to face the concepts of reactivity that are introduced starting from the concept of variance and affinity.
This leads to the equilibrium constant and the systematic introduction to equilibria in aqueous solutions.
The last part of the course introduces the fundamental concepts of electrochemistry and redox reactions.
Bibliography
Chimica Generale
Silvestroni, V ed.
Casa Editrice Ambrosiana
Teaching methods
Hopefully, the lessons will be held in person, however with the continuation of the Covid-19 emergency, the activities can be carried out in telepresence through the use of the Teams and Elly platforms. In particular, lessons will be held in both synchronous (via Teams) and asynchronous mode (uploaded on the Elly page of the course).
Assessment methods and criteria
The preparation will be verified with an oral test evaluated in thirtieths. The oral exam will consist of a question on a topic treated in class at the student's choice and on two topics chosen by the teacher. In one of these, the student will be asked to formulate a synthetic strategy to obtain a nanostructure selected by the teacher, what properties can be expected from this nanostructure, as well as what characterization approaches are necessary to validate the success of the synthetic strategy he / she proposed.
Other information
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