Berlin 2005 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 33: Novel materials I
CPP 33.1: Vortrag
Mittwoch, 9. März 2005, 09:45–10:00, TU C230
Direct measurements of mechanical properties of Pickering emulsions by AFM — •Philippe Carl1, Alexander Boker2, Qian Wang2, Yao Ling2, Thomas P. Russell2, Jhonny Rodrigues3, Bernie Binks3, Helmuth Moehwald1, and Andreas Fery1 — 1MPI fur Kolloid und Grenzflachenforschung, Am Muhlenberg, D 14424 Potsdam (Germany) — 2Department of Polymer Science & Engineering, University of Massachusetts, Amherst, MA 01003 (USA) — 3Surfactant & Colloid Group, Department of Chemistry, University of Hull, Hull. HU6 7RX. (U.K.)
Emulsions stabilized by self-assembly of particles at the fluid interfaces, driven by the reduction in interfacial energy, also called Pickering emulsions attracted much attention in the last years. These systems are interesting since they allow size-selective particle assembly, two-dimensional phase behavior, as well as functionalization, abling the fabrication of nanoscopic materials with unique optical, magnetic, and electronic properties. Moreover, the particles stabilizing the emulsion drops can also be locked together to form some elastic shells, which can be used as solid capsules with tailored size, permeability, mechanical strength, and compatibility perfectly aimed for encapsulation or drug delivery. But while the self assembly of this particles, the interaction between the particles and the interfaces and the size of the drops are well characterized, little is known so far on the mechanical properties of these emulsion drops. We report first results using colloidal probes and standard AFM techniques to directly measure the forces necessary to deform such drops and thus evaluate the influence of these parameters.