L6

a substance that is distributed (dispersed phase) in the dispersing agent

nature of interaction between dispesed phase and dispersion medium

-> hydrophilic colloids

-> hydrophobic colloids

1. Dispersed colloids

2. association colloids

3. macromolecular colloids

two fuids that dont mix

unstable

stabilize an emulsion

in the gi tract its vile acids

must be hydrophilic (soap)

in more concentrated solutions aome hydrophilic colloids harden into a gel mass

have a net like structure

1. OPTICAL- Tyndall effect, the light scatters

2. MECANICAL- brownian movement, zigzag path

3. DIALYSIS- colloid particles can not pass through the cellophane or animal bladder (purification of proteins)

4. ELECTRICALLY- colloid particles obtain charge in a polar solvent (H2O)

5. ELECTROPHORESIS- movement of charged colloidal particles in an electric field

6. ADSORPTION- sponatneous accumulation of a one subastance (adsorbate) on the other substance (adorbent) -selctive

   -rapid

   spontaneous and followed by the decrease of entropy

   -usually exotherm

weak bond

reversible

a chemicla bond is created

rearly reversible

slower than physical adsorption

usually the adsorbens is solid substance which adsorbs gases or substances from solution

1. nature of the substance

2. specific surface of the adsorbent

3. absorbate concentration (pressure)

occures when the solution with macromolecules is seperated by semipermeable membreane from pure solvent or a solution with small ions