Physical chemistry of formulations

A.Y. 2021/2022
Overall hours
Learning objectives
The aim of the course is to provide the student with the physical chemistry notions useful to interpret the behaviour of formulations, considering both fundamental and applicative aspects. Separate disciplines, in particular of colloid, surface chemistry and process technology, play a role in the formulation of an active ingredient into its commercial form
Expected learning outcomes
Students will understand the principles of making finished products from a blend of different individual ingredients. They will acquire an integrate knowledge of the diverse range of chemistry/physics sub-disciplines, the ability to define a problem, identify potential alternatives, gather appropriate knowledge and information to formulate and articulate a solution for real industrial cases; the capacity to think critically and be able to evaluate, design, and conduct research in the formulation field, studying the basic raw materials and their influences on the performance of the finished formulation.
Course syllabus and organization

Single session

Course syllabus
Concept of formulation, applications and its industrial relevance. Main ingredients of a formulation. Colloids and Interfaces: introduction to the science of colloids and surfaces. Lyophilic and lyophobic colloids. Definition of interface, dispersed system and surface tension/free interfacial energy. Intermolecular forces. Types of dispersed systems (liquid-gas, liquid-liquid and liquid-solid). Concepts of cohesion, adhesion and diffusion. Thermodynamic and kinetic stability: from diluted dispersed systems to concentrated complex mixtures.
Surfactants and their applications: definition, concepts of chemical and physical adsorption. Adsorption on liquid and liquid-solid interfaces. Role of surfactants in formulations (detergents, wetting agents, dispersants, flocculants, emulsifiers, etc). Classification of surfactants and different typologies. HLB scale. Physico-chemical properties of surfactants. Association colloids: general properties, Micellar Critical Concentration, thermodynamics and micellization kinetics. Ability to interpret technical data sheet of commercial surfactants. Use and Limitations.
Dispersions: Definition. Granulation, dispersion and spraying phenomena. Interfacial electrification phenomena. Surface wettability by contact angle measurements. Determination of particle size by conventional and novel methods (light scattering, electronic microscopy). Industrial reactor.
Emulsions: definition and types. Recognition and prediction of the emulsion type. Choice of suitable emulsifier. Bancroft rule and HLB system for classification, PIT (Phase Inversion temperature), formation and stability. Destabilization phenomena (creaming, clustering, coalescence). Production of emulsions by batch or continuous systems (primary and secondary homogenization). Application to the industrial and cosmetic world. Performance and cost evaluation.
Foams: definition and applications. Types of foam and foam structure. Stabilization of a foam (film elasticity concept, Marangoni & Gibbs effect, gas diffusion). Foaming agents, stabilizers, antifoaming additives. Foam production. Solid foam.
Role of Rheology: the importance of rheology in the science of formulations. Rheological properties of colloidal systems recall on Newtonian and non-Newtonian fluids (plastic, pseudo-plastic, dilatant). Definition of dynamic and kinematic viscosity. Viscosity of dispersions and emulsions. Reometers and viscometers. Examples of applications in the formulation industry. The role of thickeners.
Industrial applications: Coatings: definition, global comprehension of ingredients, production techniques applicable to coatings industry. Role of pigments, binders, fillers, drying agents, resins and solvents. Natural and synthetic tires. Cosmetics: definition. Description of the several administration forms (pharmaceutical ones). Fluid-solid or semi-solid forms (ointments, creams, pastes). Preservatives and antioxidants. Description of equipment intended for the production of semi-solid, solid, rubbery forms. Detergents: general principles and fundamental phenomena. Suitable additives and builders. Anionic, cationic detergents. Role of other additives (polyethylene glycol, antifoam agents, thickeners, antistatic agents and pH balancers). Agro-formulations: definition and typologies (insecticides, fungicides, herbicides, etc). Active principles. Adjuvants. Dispersion methods. Bituminous materials.
Prerequisites for admission
Basis of thermodynamic and kinetic principles. This course is strictly recommended for Master Degree students.
Teaching methods
The lectures will be carried out remotely in asynchronous mode through computer recording; they will be made available to students on the ARIEL platform.
Teaching Resources
H. Mollet, A. Grubenmann, Formulation Technology, Wiley-VCH, 2007
K. S. Birdi, Surface and Colloid Chemistry, CRC Press, 2010
L. L. Schramm, Emulsions, Foams, Suspensions and Aerosols, Wiley-VCH, 2014
Teaching material provided by the professor.
Assessment methods and Criteria
The oral exam will be held electronically via the MSTeams online platform. The examination begins with a topic chosen by the student. The ability to make connections among all the issues proposed is required. Further, the student will have to try to solve formulation problems directly connected to the industrial productions.
CHIM/02 - PHYSICAL CHEMISTRY - University credits: 6
Lessons: 48 hours