Berlin 2005 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 29: POSTER: Polymer physics
CPP 29.63: Poster
Dienstag, 8. März 2005, 16:30–18:30, Poster TU D
Linear-dendritic amphiphilic block copolymers in solution and in Langmuir-Blodgett films — •Sofiya Raleva1, Bernd Stühn1, Ahmed Sayeed1, Holger Kautz2, and Holger Frey3 — 1Instutute of Solid State Physics, Technical University Darmstadt, D-64289 Darmstadt — 2Department of Chemistry and Chemical Engineering, Eindhoven University, 5600 Eindhoven, The Netherlands — 3Institute of Organic Chemistry, Johannes Gutenberg University, D-55128 Mainz
A new type of linear-hyperbranched surfactant has been prepared by ring-opening multibranching polymerization of glycidol onto an end functional poly(propylene oxide) (PPO) macroinitiator. A hyperbranched, highly hydrophilic polyglycerol block is obtained as the polar segment of the structure. In this work we have studied the structure formation of these polymers in water and in thin films. Due to their unique architecture these amphiphiles are able to form well-defined micelles in water. SAXS in Kratky geometry was used to determine the structure factor as well as the form factor of the micelles formed in aqueous solution. Langmuir-Blodgett films were deposited from chloroform and methanol solutions at room temperature onto silicon substrate at different surface pressures. The thickness, interface roughness and electron density variation perpendicular to the surface of the so deposited layers were determined using specular X-ray reflection. In all cases we find well-separated hydrophobic and hydrophilic smooth layers. The hydrophilic layer shows a density profile, depending on the degree of polymerization of the hyperbranched block. We discuss the results with respect to the copolymer architecture and the hydrophilic/hydrophobic balance.