Dear Colleagues

171(1-3) (2000), 25-31
This report intends to draw a line from the controlled preparation and understanding of Langmuir monolayers to the fabrication of hollow capsules with exciting perspectives for basic science and applications. It is shown that methods used to characterize structure and transport properties of Langmuir and Langmuir-Blodgett films could be used to study polymeric ultrathin films. Since the latter are permeable to small molecules they could be used to prepare capsules after coating depolymerizable colloids. The inside of the capsule can be designed such that it is distinguished by inner walls and pH in the interior to perform a specific chemistry. As an application example selective precipitation of a dye molecule as a model for drug loading is presented. (C) 2000 Elsevier Science B.V. All rights reserved.

[53] Formation of Luminescent Spherical Core-Shell Particles by the Consecutive Adsorption of Polyelectrolyte and CdTe(S) Nanocrystals on Latex Colloids

A. S. Susha, F. Caruso, A. L. Rogach, G. B. Sukhorukov, A. Kornowski, H. Möhwald, M. Giersig, A. Eychmuller and H. Weller

Colloid Surf. A 163(1) (2000), 39-44

Functional core-shell particles were prepared by assembling a composite multilayer shell of charged polyelectrolytes and luminescent CdTe(S) nanocrystals (cadmium telluride with a certain content of sulfide) via their consecutive electrostatic adsorption from solution onto micron-sized latex particles. The formation of the composite shell has been confirmed by optical spectroscopy, confocal microscopy and high-resolution transmission electron microscopy. Variation of the size and surface chemistry of the semiconductor nanoparticles, the size and shape of the colloid templates, and the nature of the polyelectrolyte opens new avenues for the production of a variety of novel core-shell materials. (C) 2000 Elsevier Science B.V. All rights reserved.

[54] Lateral Lipid Diffusion in Phospholipid Monolayers Coupled to Polyelectrolyte Films

M. Auch, B. Fischer and H. Möhwald

Colloid Surf. A 164(1) (2000), 39-45

The lateral diffusion of lipid probes in lipid monolayers on polyelectrolyte support in different solvent environment was studied by a fringe pattern photobleaching experiment that enabled to measure diffusion coefficients D of over six orders of magnitude, In nonpolar solvents, as well as in air, electrostatic binding of ionic and also of zwitterionic lipids is so strong, that D < 10(-12) cm(2) s(-1) was observed. In polar solvents (e.g. methanol), the interaction is reduced for zwitterionic lipids, enabling D > 10(-7) cm(2) s(-1). In water, the coupling is similarly reduced for zwitterionic, not for ionic lipids. In the case of a weak interaction with the polymer, one encounters a temperature dependence for the monolayer of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) as expected for a system with a fluid/gel phase transition. (C) 2000 Elsevier Science B.V. All rights reserved.

[55] Polyelectrolyte Adsorption Processes Characterized in-Situ Using the Quartz-Crystal Microbalance Technique - Alternate Adsorption Properties in Ultrathin Polymer-Films

A. Baba, F. Kaneko and R. C. Advincula

Colloid Surf. A