G. Kickelbick, J. Bauer, N. Hüsing, M. Andersson, K. Holmberg:
"The binary phase behavior of short-chain PDMS-b-PEO diblock copolymers in aqueous solutions in dependence of the PDMS chain length-a combined polarized optical microscopy, 2H NMR and SAXS study.";
Colloids and Surfaces, A: Physicochemical and Engineering Aspects,
The binary phase behavior of three short-chain polydimethylsiloxane-b-poly(ethylene oxide) (PDMS-b-PEO) diblock copolymers with the compns. DMS4-b-EO12, DMS6-b-EO12 and DMS10-b-EO12 (DMS = dimethylsiloxane unit, EO = ethylene oxide unit) was studied in aq. solns. using polarizing light microscopy, deuterium NMR spectroscopy, and SAXS measurements. At low surfactant concns. all three diblock copolymers show a mixed water/lamellar phase (W + Lα), which switches to a lamellar phase depending on the DMS length and temp. in the region of 40% for DMS4 to over 50% for DMS10. The surfactants consisting of DMS4 and DMS6 show further assocn. in the concn. range between 40 and 85% predominately lamellar phases, while at high concn. a surfactant rich phase L2 developed. If the DMS segment was increased to 10 units the region between 55% and approx. 75% was dominated by a mixed inverse hexagonal and lamellar phase at higher concn. a pure inverse hexagonal and afterwards a surfactant rich lamellar phase developed, respectively.
Erstellt aus der Publikationsdatenbank der Technischen Universitšt Wien.