Analyte
Water- and organosoluble synthetic and natural polymers, nanoparticle-dispersions
- Sample mass: ~ 100 - 500 mg (depending on molar mass etc.)
- Molar mass range: 104 - 105 g/mol
Equipment
- Instrument: GONOTEC membrane osmometer OSMOMAT 090
- Solvent: water and aqueous salt solutions as well as organic solvents e.g. tetrahydrofuran, toluene, chloroform
- Membranes: cellulose triacetate (cut-off 5000, 10000 and 20000 g/mole), regenerated cellulose (cut-off 20000 g/mole)
Evaluation methods and targets
-
measurement of the osmotic pressure p against the polymer concentration and extrapolation of
the reduced osmotic pressure on zero concentration
=> number average molar mass Mn and 2nd virial coefficient A2,o
Application example
Comparative and additional methods
- Aqueous size exclusion chromatography (SEC) (Mn; MW; D)
- Organic size exclusion chromatography (SEC) (Mn; MW; D)
- Static light scattering (MW; RZ; A2)
- Analytical ultracentrifugation (MZ; D)
- Differentialrefraktometrie (dn/dc)
- dynamische Lichtstreuung (dH)
- Dampfdruckosmometrie (Mn)