2. Introduction to Colloidal systems Joachim Koetz, Universität Potsdam

3. Alchemist Elexier of life ? potable gold-solution (aurum potabile)

4. Definition ( Graham ) Colloids are glue-like substances, diffuse very slowly, and do not dialyse

5. suspensions > 1000 nm Types of disperse systems ( W. Ostwald ) Disperse systems colloidal dispersions 1 bis 1000 nm solutions < 1 nm

6. Definition Any particle that has some linear dimension between 1 nm and 1 μm is considered a colloid! However, the limits are rather arbitrary.

7. A state of subdivision in which the particles, droplets, or bubbles dispersed in another phase have at least one dimension between 1 – 1000 nm All combinations are possible between gas, liquid, and solid W. Ostwald Definition:

8. History of Colloid Chemistry 1927 Burry, Ekwall: Associating Colloids 1929 Staudinger: Macromolecules

9. Associating Colloids Amphiphilic self-organizing systems Colloids are associated physically, not chemically Size and shape of the associates can change

10. Macromolecules as colloidal systems Any macromolecule consisting of 10 3 up to 10 9 atoms Any dispersed macromolecular coil having colloidal dimensions

11. History of Colloid Chemistry 1923 Svedberg: Ultracentrifugation 1932 Ruska: Electron Microscopy

12. The Colloidal Domain One dimension between 1 and 1000 nm All combinations of dispersed matter Classification: - colloidal dispersions - associating colloids - macromolecules

13. Biomineralization Inorganic component Organic component Organism SiO 2 * x H 2 O composite of hydrocarbon and protein Diatomeen Aragonite, CaCO 3 composite of hydrocarbon and protein Perl oyster Hydroxyapatit, Ca 10 (PO 4 ) 6 (OH) 2 composite of collagenfilament and protein Bone and teeth

14. Nanoparticles as Quantendots Color effects in glases (e.g. CdS or gold) Non linear optical effects (fast optoelectronical switches) High storage capacity (optical storage)

15. Formation of Nanoparticles (Nanotechnology) Particle formation from gas phases Particle formation from droplets Particle formation from Sol-Gel-Processes

16. Nanoparticles produced by nucleation processes Colloidal Sulfur Colloidal Gold Latex Particles Nanocrystallites

17. Conditions for the production of monodisperse nanoparticles - Heterogeneous nucleation - La Mer diagram

18. Disciplines and Topics for which Colloids and colloidal phenomena are important Analytical chemistry Physical chemistry Biochemistry Material Science Petroleum Science Household products Imaging technology Adsorption phenomena, chromatography Nucleation, supersaturation, liquid crystals Electrophoresis, osmosis, ultrafiltration Ceramics, fibres, powder metallurgy Oil recovery, Milk, beer, cosmetics Emulsions, printing inks, paper coating