Two Phase Systems Flashcards
List physical properties
- Particle size & surface area
- Solubility
- Dissolution
- Crystal properties
- Stability
- Organoleptic
What are two phase systems?
Solid-liquid phases
Define crystal
Clear ice, crystals chemically well defined, high degree of order for atoms & molecules
Define ideal crystals
Perfect arrays in which the building blocks are arranged according to well defined symmetries into unit cells that are repeated in three dimensions by translations
What is amorphous material?
Atoms and molecules are arranged in a random manner, disordered state, e.g. glass
What is crystallisation from solution?
Transition of chemical from liquid solution state into solid crystalline state
Define solute, solvent and anti-solvent
Solute: chemical in liquid solution state
Solvent: liquid in which solute dissolved
Anti-solvent: liquid in which the solute is insoluble
What is supersaturation?
Addition of anti-solvent or precipitant
What is nucleation?
Formation of a small mass
What is homogenous nucleation?
Pure molecules of solute crystallise
What is heterogeneous nucleation?
Catalytic formation of crystal around an impurity
Define crystal growth
Addition of more solute molecules to the formed nuclei
What are supercritical fluids?
Substances above their critical temperature and pressure
What properties does supercritical fluids combine?
- Viscosity & dispersion(gas)
- Density (liquid)
Why do supercritical fluids have a high dissolution capacity?
Due to their high density
