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.
Basis of thermodynamic and kinetic principles. This course is strictly recommended for Master Degree students.
Materiale di riferimento
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.
Modalità di verifica dell’apprendimento e criteri di valutazione
Oral: 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.