- Descrições dos simpósios
- General Timetable
- Horário das apresentações orais e de posters

Materials Science has always been driven by the desire to transform matter into something more useful which is typically also thought to be more valuable. One of the important instruments for creating ordered systems is molecular self-organization based on molecules which undergo molecular self-assembly. However, even simple devices are often multimaterial composites with a hierarchical structure. It is evident that basic self-assembly methods will not be able to address molecular organization at this level of complexity and, as a consequence, multistep assembly procedures will need to be employed for the (nano)fabrication of such materials or devices. Layer-by-layer (LbL) assembly has, over the last years, developed into a method which begins to make it possible to construct multimaterial soft-matter devices by rational design and has thus kindled widespread interest in such nanohybrids. Electrostatic interactions between anionic and cationic compounds (e. g. synthetic or natural polyions such as polyelectrolytes, DNA, proteins or even colloids) offer five major advantages:

• layer-by-layer construction due to surface charge reversal in each layer
• restriction to single layers due to repulsion between last layer and excess material in each deposition cycle
• low steric demand for interaction between oppositely charged ions
• deposition on almost any solvent accessible surface
• easy access to (bio)functional multicomposite films

Since the technique allows to interface a wide variety of (bio)materials with predefined spatial arrangement, it has successfully been introduced to both materials science and applied bio-sciences. Starting with some key examples, it will be outlined where this nanofabrication technology has arrived today. This journey will take us from examples of LBL-films containing e.g. simple polyelectrolytes and extend to films in which the composition of the film controls the interaction with living cells. Besides a demonstration of the exceptional structural control in the fabrication of such films, some recent surprises while assembling LBL-films will be discussed. Such surprises concern e.g. unusual effects of polyelectrolyte concentrations or eventually, unexpected consequences of the variation of the stoichiometric balance. The functionalization of nanoparticles and recent applications in thin film devices will briefly be discussed and the presentation will finish with the construction of multilayers containing cells and with devices for biomedical use.

Some references:
(1) Decher, G., Layered Nanoarchitectures via Directed Assembly of Anionic and Cationic Molecules; in: Comprehensive Supramolecular Chemistry, Vol. 9,
"Templating, Self-Assembly and Self-Organization" (Sauvage, J.-P. and Hosseini, M. W., Eds.), Pergamon Press: Oxford, 1996; 507-528.
(2) Decher, G.; Eckle, M.; Schmitt, J.; Struth, B., Layer-by-Layer assembled multicomposite films, Curr. Opinion Coll. & Interf. Sci. 3, 32-39 (1998).
(3) Bertrand, P.; Jonas, A.; Laschewsky, A. and Legras, R., Ultrathin polymer coatings by complexation of polyelectrolytes at interfaces: suitable materials,
structure and properties. Macromol. Rapid. Commun. 21, 319-348 (2000).
(4) Paula T. Hammond, Recent explorations in electrostatic multilayer thin film assembly. Curr. Opinion Coll. & Interf. Sci. 4, 430-442 (2000).
(5) Multilayer Thin Films: Sequential Assembly of Nanocomposite Materials; Decher, G. and Schlenoff, J. B., eds., Wiley-VCH: Weinheim, 2003; 524 pages.
(6) Zhiyong Tang, Ying Wang, Paul Podsiadlo and Nicholas A. Kotov, Biomedical Applications of Layer-by-Layer Assembly: From Biomimetics to Tissue
Engineering, Adv. Mater. 18, 3203–3224 (2006).
(7) Johnston A.P.R., Cortez C., Angelatos A.S. and Caruso F., Layer-by-layer engineered capsules and their applications, Curr. Opinion Coll. & Interf. Sci. 11,
203-209 (2006).
(8) Katsuhiko Ariga, Jonathan P. Hill and Qingmin Ji, Layer-by-layer assembly as a versatile bottom-up nanofabrication technique for exploratory research
and realistic application. Phys. Chem. Chem. Phys. 9, 2319–2340 (2007).
(9) N. Jessel, P. Lavalle, V. Ball, J. Ogier, B. Senger, C. Picart, P. Schaaf, J.-C. Voegel and G. Decher, Polyelectrolyte Multilayer Films – A General Approach to
(Bio)-Functional Coatings, in Macromolecular Engineering Vol. 2, “Elements of Macromolecular Structural Control” (Y. Gnanou, L. Leibler and K.
Matyiaszewski, Eds.), Wiley-VCH: Weinheim, 2007, 1249-1306.