651-3008/02 – Dispersion Systems (DS)
| Gurantor department | Department of Chemistry and Physico-Chemical Processes | Credits | 6 |
| Subject guarantor | prof. Ing. Jana Dobrovská, CSc. | Subject version guarantor | prof. Ing. Jana Dobrovská, CSc. |
| Study level | undergraduate or graduate | Requirement | Compulsory |
| Year | 1 | Semester | summer |
| | Study language | Czech |
| Year of introduction | 2022/2023 | Year of cancellation | |
| Intended for the faculties | FMT | Intended for study types | Follow-up Master |
Subject aims expressed by acquired skills and competences
- to use of thermodynamic quantities for the description of colloidal and
coarse dispersed systems,
- to describe the properties of colloidal dispersion systems - kinetic,
mechanical, electrical and optical,
- to monitor the stability of disperse systems, the possibility of influencing
stability,
- to assess the effect of interfacial properties on heterogeneous disperse
systems - interfacial tension, contact angle, Young-Laplace equation, Kelvin
equation, the Gibbs adsorption isotherm, adsorption equilibrium,
- to apply obtained theoretical knowledge in tutorials and laboratory and on
selected processes of chemical practice.
Teaching methods
Lectures
Individual consultations
Tutorials
Experimental work in labs
Summary
This course deals with the physico-chemical properties of colloidal systems, surfaces and multiphase systems. Classifies dispersion systems, based on the dispersity, particle size distribution function, optical, electrical, molecular-kinetic properties of colloidal systems, and the structure of colloidal particles. Describes the physical chemistry of phase boundaries, phase dispersion systems, molecular colloids.
Compulsory literature:
Recommended literature:
Way of continuous check of knowledge in the course of semester
FULL-TIME STUDY
List of conditions for obtaining of credit:
- required attendance at the exercises
- two written tests
- passing the required number of laboratory exercises, elaboration and defense
of laboratory protocols.
Points scoring for credit:
Min. number of points - 20
Max. number of points - 45
Points scoring for examination - combined examination.
The examination consists of two parts - written and oral examination.
Written examination (min. number of points - 5, max. number of points - 15)
Oral examination (min. number of points - 10, max. number of points - 40)
E-learning
Other requirements
No other activities are required.
Prerequisities
Subject has no prerequisities.
Co-requisities
Subject has no co-requisities.
Subject syllabus:
1. Colloidal systems. Preparation, condensation and dispersion methods,
significance in industry and environment, degree of dispersion, particle
size distribution functions and experimental determination of particle size
distributions.
2. Properties of colloidal systems – optical (Tyndall effect, nefelometry),
kinetic (Brownian motion, diffusion of colloidal particles) and electrical
(electrophoresis, sedimentation potential, streaming potential, electro-
osmosis). 3. Structure of colloidal particles. Electrical charge of
colloidal particles, micelle, theory and models of electrical double layer
- Helmholtz double layer, Gouy-Chapman double layer, Stern modification of
diffuse double layer. Lyophilic and lyophobic colloids, preparation and
stability.
4. State changes of colloidal systems. Coagulation, coalescence, sols and
gels, xerogels, swelling, thixotropy. Methods for separations colloidal
systems. Dialysis, electrodialysis, filtration, electro- ultrafiltration,
ultrafiltration, electro-decantation.
5. Coagulation. Coagulation threshold. Coagulation and adsorption. Hardy-
Schultz rule, lyotropic (Hofmeister) series. Coagulation kinetics of
monodispersed systems. Basic conceptions of coagulation kinetics of
polydispersed systems. Swelling kinetics.
6. Sedimentation of colloid particles. Sedimentation in the gravitational
field and sedimentation in the centrifugal field. Sedimentation equilibrium
and rate. Determination of molar masss weight by sedimentation.
7. Motion of colloidal particles. Stokes' law. Diffusivity and mobility of
colloidal particles. Movement of colloidal particles in electric field.
8. Passage of dispersion systems through membranes. Theory of the Donnan
membrane equilibrium. Osmotic pressure and viscosity of colloidal systems.
Einstein relation.
9. Emulsions - preparation and stability. Emulsifiers, stabilisers of
emulsions, their physicochemical action. Foams, preparation, stability and
utilization.
10. Surface phenomena. Free surface energy, surface and interfacial tension.
Wetting of solid surface by liquid, Laplace equation, contact angle,
measurement methods. Interfacial phenomena on interface between two
immiscible liquids. Surface films.
11. Adsorption on liquid-liquid and gas-liquid phase interface. Gibbs
adsorption isotherm, surface-active and surface-nonactive agents.
Flotation principles.
12. Adsorption on liquid-solid and gas-solid phase interface. Adsorption of
gases on solid surfaces. Adsorption from solutions on solids. Adsorption
isotherms (Freundlich and Langmuir isotherms, BET model of adsorption).
Factors affecting adsorption. Adsorption hysteresis. Adsorption kinetics.
13. Angular phase interface. Kelvin’s equation. Dissolution of solid
substances. Thermodynamics and kinetics of crystallization from solutions.
Distribution coefficient, principles of extraction.
14. Polymer systems. Theory and thermodynamics of macromolecules. Flory-
Huggins theory.
Theoretical exercises:
- Introduction - introduction to exercise timetable, conditions for obtaining
credit and recommended reading. Size of dispersed particles, the degree of
dispersity, differential and integral distribution function of particle
size, average molar mass.
- Electrokinetic phenomena, kinetics of coagulation.
- Sedimentation and gross sedimentation equilibrium colloidal dispersion
systems.
- Osmotic pressure, membrane equilibrium membrane hydrolysis.
- Surface films, adsorption of the movable interface.
- Adsorption on a solid phase interface from the gas phase and solution.
- Calculation test.
Laboratory exercises:
- Safety in the laboratory, an introduction to laboratory assignments, basic
information on the exercises and the formulation of requirements for
protocol processing.
- Determination of the constants of adsorption isotherm of acetic acid on
charcoal.
- Determination of strongly acidic cation exchange capacity in a standard
condition.
- The critical micelle concentration of sodium lauryl sulfate.
- The titration curves of ion exchangers.
- Determination of the degree of swelling depending on the pH of the gelatin
solution.
- Adsorption on a mobile interface.
- Sizing hydration package of gelatin.
- Adsorption of methylene blue on activated carbon.
- Determination of some physical properties of ion exchangers.
- Evaluation of content and formal level protocols, credit.
Conditions for subject completion
Occurrence in study plans
Occurrence in special blocks
Assessment of instruction