Analyte
Synthetic and native polymers which are soluble in water or any organic solvent,
dispersions of nanoparticles
- Sample mass: < 100 mg
- Molar mass range: 103 - 1014 g/mol
- Particle size range: 1 - 500 nm
Equipment
- Gerät: Analytical ultracentrifuge Optima XL-I (Beckman-Coulter, USA)
- Rotor speed: 2,000 bis 60,000 U/min
- Solvents: Water or aqueous buffers, organic solvents (e.g. THF, Toluol, DMF, DMF+LiCl, DMAc etc.)
- Sample cells: double sector cells made from Carbon filled Epon, aluminium or titanium; multi-channel cells for sedimentation equilibrium; synthetic boundary cells
- Detection systems: UV-Vis-Absorption (200 - 800 nm), Interference, (Schlieren-Optics - MOM3180)
Evaluation Methods and Targets
-
Sedimentation velocity measurement
=> sedimentation coefficient s and s-distribution g(s)
=> average molar mass / mass distribution by means of s-M-calibration or by combination with intrinsic viscosity or coefficient of diffusion (Svedberg Equation)
=> size distributions of nano particles (Stokes law) -
Sedimentation equilibrium measurement
=> absolute values of average molar masses Mw, Mz und 2nd virial coefficient A2,o -
Synthetic boundary experiment at low rotor speed
=> coefficient of diffusion Dx -
Synthetic boundary experiment for the generation of density gradients
=> density ρ or density distribution g g(ρ) of polymer particles
Application Examples
Contact
Dr. Eckhard Görnitz
Research devision
Water-born Polymer Systems
phone +49 (0) 331/ 568-1302
fax +49 (0) 331/ 568-3000
email Eckhard.Goernitz@iap.fraunhofer.de
Research devision
Water-born Polymer Systems
phone +49 (0) 331/ 568-1302
fax +49 (0) 331/ 568-3000
email Eckhard.Goernitz@iap.fraunhofer.de
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)
- Viskosimetrie ([η])
- Dynamische Lichtstreuung (dH)
- Vapor pressure osmometry (Mn)
- Measurement of the partial specific volume ν