Main lectures

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ML01

SELF-ORGANIZED MACROMOLECULAR AND SUPRAMOLECULAR SYSTEMS: FROM DESIGN TO REALITY

K. E. GECKELER

Laboratory of Applied Macromolecular Chemistry, Department of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), 1 Oryong-dong, Buk-gu, Gwangju 500-712, South Korea (keg/gist.ac.kr, http://mse.gist.ac.kr/~mseamc )

Self-organized systems have attracted great interesst and have been found to be important in may respect. The use of nanosized building blocks in conjunction with other molecules such as organic macrocylces and hydrophilic polymers allows designing and developing new concepts for the synthesis of novel macromolecular and supramolecular systems. To this end, versatile synthons can be applied both in nanoscience and supramolecular chemistry. These different fundamental concepts are presented and highlighted both as synthetic approaches and in the context of their applications.

Several model systems with carbon nanotubes have been studied and examples of self-organized products based on different types of reactions and syntheses are given. Supramolecular conjugates presented are based on the use of single- and multi-walled carbon nanotubes for the supra­molecular constructs. The novel self-organized systems are expected to have an application potential in many areas such as the biomedical and electronic areas.

References

1.K. E. Geckeler, Trends Polym. Sci., 2, 355 (1994).

2.K. E. Geckeler (Ed.), Advanced Macromolecular and Supramolecular Materials and Processes, Kluwer Academic/Plenum Publishers, 2003.

3.K. E. Geckeler and E. Rosenberg (Eds.), Functional Nanomaterials, American Scientific Publishers, Valencia, USA, 2006.


ML02

ENGINEERING WITH (SUPRA)MACROMOLECULES: FROM SELF-ORGANIZED SYSTEMS TO NEW FUNCTIONS

U.S.SCHUBERT

Laboratory of Macromolecular Chemistry and Nanoscience

Eindhoven University of Technology & Dutch Polymer Institute

P.O. Box 513, 5600 MB Eindhoven, The Netherlands. E-mail: u.s.schubert/tue.nl

Metallo-supramolecular block copolymers represent a new class of compounds, where an asymmetric bis-terpyridine ruthenium(II) complex serves as the supramolecular linker between two different polymer blocks. A two-step self-assembly process is employed: first only one ligand is chelated around a ruthenium(III) metal ion. This so-called mono complex can be isolated and coupled with any other kind of terpyridine ligand under reducing conditions. Asymmetric bis-terpyridine ruthenium(II) complexes can thus be prepared and if the ligands are connected to polymers, metallo-supramolecular block copolymer are obtained.1,2 Due to the inertness of ruthenium-terpyridine complexes, only A-B block copolymers are being formed. The introduction of terpyridine ligands at the chain ends of a polymer will be discussed by using end group modification reactions and by using terpyridine functionalized initiators suitable for controlled radical polymerizations as well as the utilization of anionic processes.3 Characterization of these systems is not straightforward due to the intrinsic charge and therefore some attention will be given to techniques such as analytical ultracentrifugation and special GPC-setup’s.4 Studies on the bulk morphology will be presented by small angle x-ray scattering, atomic force microscopy and trans­mission electron microscopy and compared with their covalent analogues. Additional aggregation of the metal complexes was found by SAXS (and explained by modeling studies) due to electro­static interactions between the metal complexes of neighboring chains.5 Manipulation of amphiphilic diblock copolymers into micelles will be briefly discussed, which have been further analyzed by analytical ultracentrifugation.6 The strength of coupling two polymers together via a metal complex for investigation of structure-property relationships will be demonstrated by the preparation and analysis of a metallo-supramolecular block copolymer library based on polystyrene and poly(ethylene oxide).7 Moreover, some preliminary experiments with respect to the reversibility of bis-terpyridine ruthenium complexes will be discussed as an outlook on possible future applications in nanotechnology, such as functional patterned surfaces.8 Besides AB and ABC block copolymers also ABA and chain extended linear polymers were investigated.9 Finally, the first examples combining the metallo-supramolecular connec­tion with strong hydrogen-bonding or biotin-(strept)avidin units will be shown.10

References

1.     U.S. Schubert, H. Hofmeier, G.R. Newkome, Modern Terpyridine Chemistry, Wiley-VCH, Weinheim, 2006.

2.     B.G.G. Lohmeijer, U.S. Schubert, Angew. Chem. Int. Ed. 41, 3825 (2002); H. Hofmeier, U.S. Schubert, Chem. Soc. Rev. 33, 373 (2004); P.R. Andres, U.S. Schubert, Adv. Mater. 16, 1043 (2004).

3.     B.G.G: Lohmeijer, U.S. Schubert, J. Polym. Sci.: Part A: Polym. Chem. 41, 1413 (2003); B.G.G: Lohmeijer, U.S. Schubert, J. Polym. Sci.: Part A: Polym. Chem. 42, 4016 (2004); B.G.G: Lohmeijer, U.S. Schubert, J. Polym. Sci.: Part A: Polym. Chem. 43, 6331 (2005); C.Guerrero-Sanchez, B.G.G. Lohmeijer, M.A.R. Meier, U.S. Schubert, Macromolecules 38, 10388 (2005).

4.     M.A.R. Meier, B.G.G. Lohmeijer, U.S. Schubert, Macromol. Rapid Commun. 24, 852 (2003); C. Tziatzios, B.G.G. Lohmeijer, L. Börger, U.S. Schubert, D. Schubert, Prog. Colloid Polym. Sci. 127, 54 (2004); M.A.R. Meier, H. Hofmeier, C.H. Abeln, C. Tziatzios, M. Rasa, D. Schubert, U.S. Schubert, e-polymers, in press (2006); M. Rasa, U.S. Schubert, Soft Matter, in press (2006).

5.     M. Al-Hussein, B.G.G. Lohmeijer, U.S. Schubert, W. H. de Jeu, Macromolecules 36, 9281 (2003);  M. Al-Hussein, B.G.G. Lohmeijer, U.S. Schubert, W. H. de Jeu, Macromolecules 38, 2832 (2005); A.V. Kyrylyuk, B.G.G. Lohmeijer, U.S. Schubert, Macromol. Rapid Commun. 26, 1948 (2005).

6.     J.-F. Gohy, B.G.G. Lohmeijer, U.S. Schubert, Macromolecules 35, 4650 (2002); V. Vogel, J.-F. Gohy, B.G.G. Lohmeijer, J.A. van den Broek, W. Haase, U.S. Schubert, D. Schubert, J. Polym. Sci.: Part A: Polym. Chem. 41, 3159 (2003); J.-F. Gohy, B.G.G. Lohmeijer, A. Alexeev, X.-S. Wang, I. Manners, M.A. Winnik, U.S. Schubert, Chem. Eur. J. 10, 4315 (2004).

7.     B.G.G. Lohmeijer, D. Wouters, Z. Yin, U.S. Schubert, Chem. Commun. 2886 (2004).

8.     C.-A. Fustin, A.-S. Duwez, B.G.G. Lohmeijer, U.S. Schubert, J.-F. Gohy, Adv. Mater. 17, 1162 (2005).

9.     M.A.R. Meier, D. Wouters, C.Ott, P. Guillet, C.-A. Fustin, J.-F. Gohy, U.S. Schubert, Macromolecules 39, 1569 (2006).

10.   H. Hofmeier, A. El-ghayoury, A.P.H.J. Schenning, U.S. Schubert, Chem. Commun. 318 (2004); H. Hofmeier, J. Pahnke, C.H. Weidl, U.S. Schubert, Biomacromolecules 5, 2055 (2004); H. Hofmeier, U.S. Schubert, Chem. Commun. 2423 (2005); H. Hofmeier, R. Hoogenboom, M.E.L. Wouters, U.S. Schubert, J. Am. Chem. Soc. 127, 2913 (2005).


ML03

HIGHER-ORDER STRUCTURES IN BLOCK COPOLYMER MICELLES

T. P. LODGE

Department of Chemistry and Department of Chemical Engineering & Materials Science, University of Minnesota, 207 Pleasant Street SE, Minneapolis MN 55455-0431, USA (lodge/chem.umn.edu)

The ability of block copolymers to self-assemble spontaneously into micelles, when dispersed in a solvent that is good for one block and poor for the other, is well-known. The prevalent micellar morphologies are spheres, cylinders (or worms), and bilayers (usually curved around to form vesicles), and the factors that dictate the selection of morphology (interfacial tension, corona crowding, and core block stretching) are also understood. However, these micelles, as with their small molar mass amphiphile analogs, are constrained to divide space into two domains: an “inside” and an “outside”. We have been interested in creating multicompartment micelles, i.e., structures in which the solvophobic cores are further subdivided into distinct nanodomains.

A prototypical system of mikto-arm star terpolymers, comprising a water soluble arm (polyethylene oxide), a hydrophobic arm (polyethylethylene), and a lipophobic and hydrophobic fluorocarbon arm (polyperfluoropropylene oxide), has exhibited great promise in this regard.  When dispersed in water, these terpolymers self-assemble into a fascinating array of multicompartment micelles, including structures termed hamburgers, segmented worms, and laterally nanostructured vesicles. Cryogenic transmission electron microscopy has been used to image these micelles directly. The synthesis and characterization of the terpolymers, the factors that dictate the choice of structure, and possible applications of these systems will be discussed.


ML04

VINYL AMIDE-BASED HOMO- AND COPOLYMERS: SYNTHESIS BY CONTROLLED RADICAL POLYMERIZATION AND INVESTIGATION OF THEIR SOLUTION BEHAVIOR

Y. GNANOU

Laboratoire de Chimie des Polymères Organiques,ENSCPB-CNRS-Université Bordeaux-1,16, Avenue Pey-Berland, 33607 Pessac –France, gnanou/enscpb.fr

In the past decade, the discovery of methods that bring about “living”/controlled polymerizations by radical means has resulted in the synthesis of various well-defined polymeric architectures. For instance, nitroxide-mediated polymerization and atom transfer radical polymerization (ATRP) are two examples of “living”/controlled processes, which allow control over molar mass and molecular architecture (e.g., diblock, grafted or tapered copolymers).

However, monomers such as N-vinylpyrrolidone (NVP) and N-vinylcaprolactam (NVCL) could not be polymerized under “living”/controlled conditions by any of the above mentioned methods. The recently developed RAFT (reversible addition-fragmentation chain transfer) process, which employs thiocarbonylthio compounds, could be successfully applied in the polymerization of NVP and NVCL. Both NVP and NVCL were successfully polymerized by RAFT process using either diphenyldithiocarbamate of diethylmalonate (DPCM) or methyl 2-(ethoxycarbonothioylthio) propanoate (xanthate) as chain transfer agent in the presence of a conventional radical initiator (AIBN). The molar masses of poly(N-vinylpyrrolidone) (PNVP) and poly(N-vinylcaprolactam) (PNVCL) synthesized under these conditions were found to increase with conversion and time and to corresponding almost ideally with the expected values. In all cases the SEC traces of these polymers revealed monomodal and narrow distributions.

table

The living nature of these polymers were confirmed by synthesizing amphiphilic block copolymers with styrene, n-butyl acrylate (n-BA), maleic anhydride (MAH) etc. by sequential addition of monomers. Star-shaped PNVP could also be obtained by reacting PNVP-b-(MAH-alt-PNVP) with diamines. PNVCL-b-PNVP shows self-assembly (áRhñ@200 nm) in aqueous solutions in the temperature range of 60-65 °C due to thermal sensitivity of PNVCL. The áRhñ value of the self-assembled aggregates was found to vary with the polymer concentration. These monodisperse aggregates exhibited a spherical shape as shown by their áRhñ value which was independent of the angle of detection and by TEM images. Colloidally stable nanoparticles with áRhñ@108 nm were formed upon heating the homopolymer of PNVCL to 40 °C and the nanoparticlesformed could be stabilized even at room temperature upon addition of a strong hydrophobe.



ML05

CONTROL AND SWITCHING OF ELECTRICAL AND OPTICAL POLYMER PROPERTIES BASED ON SELF-ASSEMBLED COMPLEXES

O. IKKALAa

aLaboratory of Optics and Molecular Materials, Department of Engineering Physics and Mathematics, Helsinki University of Technology, P.O. Box 2200, FIN-02015 TKK, Espoo, Finland (Olli.Ikkala/tkk.fi)

Self-assembly, which results from competing interactions, allows spontaneous periodic structure formation. Hierarchical structures can be achieved if structural units of different sizes are used.(1) To prevent phase separation, supramolecular design principles are useful, using hydrogen bonds, ionic interactions, coordination, and more complex interactions. The structures allow tuning of different properties, eg. electrical, optical, porosity, surface properties etc. Here the versatility of such an approach is illustrated by using three different groups of materials. By combining block copolymers (typically allowing self-assembly at the length scale at ca. 10-150 nm) and surfactant-like oligomers (typically allowing self-assembly at the length scale at ca. 1-5 nm), capable of selective bonding to the block copolymer, hierarchical structures are achieved, whose phase transitions manifest in photonic bandgap and protonic conductivity (collaboration with G ten Brinke and J Ruokolainen et al) (2,3). Towards conjugated materials, ionically self-assembled complexes of tetrameric aniline oligomers and phosphoric acid surfactants allow three orders of magnitude reversible conductivity change between the low temperature columnar liquid cystalline state and the high temperature disordered state (collaboration with C Faul et al) (4). The final example discusses polyaniline complexes with polyethylene oxide benzene sulfonic acid, where the side chain crystallization and melting causes reversible conductivity modulation (5).

1. Functional Materials based on Self-Assembly of Polymeric Supramolecules, O. Ikkala and G. ten Brinke, Science, 295, 2407-2409 (2002).

2. Self-assembled polymeric solid films with temperature-induced large and reversible photonic-bandgap switching, S. Valkama, H. Kosonen, J. Ruokolainen, T. Haatainen, M. Torkkeli, R. Serimaa, G. ten Brinke, and O. Ikkala, Nature Materials, 3(12), 872-876 (2004).

3. Switching Supramolecular Polymeric Materials with Multiple Length Scales, J. Ruokolainen, R. Mäkinen, M. Torkkeli, T. Mäkelä, R. Serimaa, G. ten Brinke, O. Ikkala, Science, 280, 557-560 (1998).

4. Self-Assembly and Electrical Conductivity Transitions in Conjugated Oligoaniline/Surfactant Complexes, Z. Wei, T. Laitinen, B. Smarsly, O. Ikkala, C.F.J. Faul, Angewandte Chemistry, 44(5), 751-756 (2005).

5. Electrical Conductivity Transitions and Self-Assembly in Comb-Shaped Complexes of Polyaniline Based on Crystallization and Melting of the Supramolecular Side Chains, M. Vilkman, H. Kosonen, A. Nykänen, J. Ruokolainen, M. Torkkeli, R. Serimaa, and O. Ikkala, Macromolecules, 38(18), 7793-7797 (2005).


ML06

TUNING SOFT, HYDRATED INTERFACES COMPOSED OF TETHERED POLYMER LAYERS WITH MULTI-VALENT, IONIC INTERACTIONS

A. ISHIKUBOa, d, F. LIa, J. MAYSb, c, M. TIRRELLa*

aShiseido Research Center, 2-2-1 Hayabuchi, Tsuzuki-ku, Yokohama-shi 224-8558, JAPAN

bDepartment of Chemistry, University of Tennessee,Knoxville, TN 37996, USA

cChemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA

dDepartments of Chemical Engineering and Materials, Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, CA 93106, USA

End-tethered polyelectrolyte layers (“brushes”) shrink monotonically in response to addition of mono-valent salt, which also produces corresponding monotonic changes in the range of the repulsive normal forces exerted by such brushes. High swelling and very low frictional forces have been reported under low salt concentrations. A new pattern of behavior is demonstrated here via surface force measurement on polyelectrolyte brushes in the presence of multi-valent ionic interactions, introduced via tri-valent aluminum cations (Al3+) or aggregates of cationic surfactants. Very low concentrations of added Al3+ or surfactant produce much stronger shrinkage of the brush than does mono-valent salt. Normal forces become strongly attractive under these circumstances. Multi-valent interactions enable tuning of polyelectrolyte brush structure and properties over a wide range, from compact, stiff and sticky to swollen, soft and repulsive. In this paper, we demonstrate, using the SFA, that addition of multi-valent ions, or agents that form multi-valent aggregates in solution, can not only contract polyelectrolyte brushes (quite dramatically) but also change the sign of interaction forces between polyelectrolyte brushes from repulsive to attractive and back again. Furthermore, we quantify the magnitudes of the attractive interactions between polyelectrolyte brushes in media of various ionic nature.


ML07

CRYO-TEM OF POLYMER SELF-AGGREGATION IN SOLUTION

Y. TALMON

Department of Chemical Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel

Cryo-TEM has become an indispensable tool to acquire high-resolution direct images of complex liquids, namely liquids with structure on the order of nanometers to micrometers. The methodology that has been developed over the years allows us to capture the nanostructure in its native state of fixed concentration and temperature. A wide range of systems of low- and high-molecular weight solutes, synthetic and biological has been studied already by the technique. While most cryo-TEM work has been done on aqueous systems, more recently the technique has been extended to non-aqueous solvents as well.

The term ‘cryo-TEM’ actually refers to the two techniques: direct-imaging cryo-TEM, by which a thin vitrified sample is examined by the TEM at cryogenic temperatures, and ‘freeze-fracture-replication’ cryo-TEM (FFR), by which a carbon-metal replica of the fractured fast-cooled specimen is examined at room temperature by the TEM. The two techniques are complementary, as I will explain in my talk.

The presentation will begin with a brief description of the two techniques with emphasis on FFR, a most useful technique that is, unfortunately, quite rarely used nowadays. This will be followed by a discussion of the application of cryo-TEM to non-aqueous systems, pointing out the potential and the difficulties of this type of application. A survey of recent applications of cryo-TEM is to follow. This will focus on sophisticated ways to design and perform cryo-TEM experiments. One example is given below in Figure 1. The direct visualization of the change in dimensions of polymer micelles, as the solvent properties are changed by the change of temperature.

Fig. 1. Cryo-TEM images of PS-PNIPAM latex particles of in water at 5 °C (A) and 45 °C (B). Note the change in the size of the PNIPAM “corona” with change of solvent properties.


ML08

ATOM TRANSFER RADICAL POLYMERISATION: A VERSATILE TOOL FOR THE POLYMER CHEMIST

S.P. ARMES

The University of Sheffield, Dainton Building, Department of Chemistry, The University of Sheffield, Brook Hill, Sheffield, S3 7HF, South Yorkshire, UK

Atom Transfer Radical Polymerisation (ATRP) was developed independently by Matyjaszewski’s group and Sawamoto et al. about a decade or so ago. There is no doubt that this powerful and versatile technique has made it much easier for polymer chemists to design new, sophisticated architectures based on functional monomers. This paradigm shift is illustrated in this lecture, in which the following six themes will be discussed:

1. Synthesis of a series of near-monodisperse poly(2-hydroxyethyl methacrylates) and assessment of their aqueous solubility;

2. Preparation of degradable-branched copolymers for ‘proof-of-structure’ studies;

3. Investigation of the evolution of branching with monomer conversion for branched vinyl copolymers prepared under ‘pseudo-living’ conditions;

4. Design of peptide-degradable fibres using branched poly(2-hydroxyethyl methacrylate) copolymers.

Some of this work has been recently published. Relevant references include:

“Stimulus-responsive water-soluble polymers based on 2-hydroxyethyl methacrylate”, J. V. M. Weaver, I. Bannister, K. L. Robinson, X. Bories-Azeau, S. P. Armes, P. McKenna and M. Smallridge, Macromolecules, 37, 2395-2403 (2004).

“Synthesis and chemical degradation of branched vinyl polymers prepared via ATRP: use of a cleavable disulfide-based branching agent”, Y. Li and S. P. Armes, Macromolecules, 38, 8155-8162 (2005).

“Biochemically-degradable, stimulus-responsive triblock copolymer gelators”, C. Li, P. J. Madsen, S. P. Armes and A. L. Lewis, Angewandte Chem. in the press (2006).

“Synthesis and peptide-induced degradation of biocompatible fibres based on highly branched poly(2-hydroxyethyl methacrylate)” L. Wange, C. Li, A. J. Ryan and S. P. Armes*, Advanced Materials, in the press (2006).


ML09

STRUCTURE FORMATION IN SELF-ORGANIZED BLOCK COPOLYMER BASED HYBRID SYSTEMS

U. WIESNER

Departments for Material Science and Engineering, Chemical and Biomolecular Engineering, and Chemistry and Chemical Biology

Cornell University, 330 Bard Hall, Ithaca, NY 14853

Phone: (607) 255 3487; Fax: (607) 255 2365; e-mail: ubw1/cornell.edu

The study of polymer based self-assembly (“bottom-up”) approaches to multifunctional organic-inorganic nanohybrids and nanobiohybrids is an exciting emerging research area interfacing solid state and soft materials and offering enormous scientific and technological promise. By choice of the appropriate synthetic polymers as well as iorganic precursors unprecedented morphology control down to the nanoscale is obtained in nanohybrids. Tailoring of the polymer–inorganic interface is of key importance. The structures generated on the nanoscale are a result of a fine balance of competing interactions, a typical feature of complex biological systems. The potential for new multifunctional materials lies in the versatility of the polymer chemistry as well as that of the solid state chemistry that can be exploited in the materials synthesis. In the present contribution the synthesis and characterization of nanostructured hybrid materials will be presented with potential applications ranging from microelectronics to nanobiotechnology. Cooperative self-assembly of organic and inorganic species is induced, e.g., by amphiphilic macromolecules, either block copolymers or extended amphiphilic dendrons, blocked species with one block being highly branched. Besides amorphous and crystalline oxide materials novel systems toward high temperature SiCN and SiC structures are introduced. Other examples will include the preparation of mesoporous materials and superparamagnetic mesoporous materials with pore sizes ranging from 5-50 nm for separation technology and catalysis, solid hybrid polymer electrolytes for battery applications, thin film materials with potential applications in microelectronics and nanobiotechnology as well as nanobiohybrids from novel fluorescent core-shell nanoparticles (Cornell Dots) for applications in bioimaging and biosensing.

Selected References:

1.) H. Ow, D. R. Larson, M. Srivastava, B. A. Baird, W. W. Webb, U. Wiesner, Bright and Stable Core-Shell Fluorescent Silica Nanoparticles, Nanoletters 5 (2005), 113-117.

2.) A. Jain, G. E. S. Toombes, L. M. Hall, S. Mahajan, C. B. W. Garcia, W. Probst, S. M. Gruner, U. Wiesner, Direct Access to Bicontinuous skeletal Inorganic Plumber’s Nightmare networks from block copolymers, Angew. Chem. Int. Ed. 44 (2005), 1226-1229.

3.) M. Kamperman, C. B. W. Garcia, P. Du, H. Ow, U. Wiesner, Ordered Mesoporous Ceramics Stable up to 1500°C from Diblock Copolymers, J. Am. Chem. Soc. 126 (2004), 14708-14709.

4.) B.-K. Cho, A. Jain, S. M. Gruner, U. Wiesner, Mesophase Structure-Mechanical and Ionic Transport Correlations in Extended Amphiphilic Dendrons, Science 305 (2004), 1598-1601.

5.) C. B. W. Carcia, Y. Zhang, F. DiSalvo, U. Wiesner, Mesoporous Aluminosilicate Materials with Superparamagnetic g-Fe2O3 Particles Embedded in the Walls, Angew. Chem. Int. Ed. 42, (2003), 1526 – 1530.

6.) A. C. Finnefrock, R. Ulrich, A. Du Chesne, C. C. Honeker, K. Schumacher, K. K. Unger, S. M. Gruner, U. Wiesner, Metal-Oxide-Containing Mesoporous Silica with Bicontinuous Plumber’s Nightmare Morphology from a Block Copolymer-Hybrid Mesophase, Angew. Chem. Int. Ed. 40 (2001), 1208-1211.

7.) M. Templin, A. Franck, A. Du Chesne, H. Leist, Y. Zhang, R. Ulrich, V. Schädler, U. Wiesner, Organically Modified Aluminosilicate Mesostructures from Block Copolymer Phases, Science 278 (1997), 1795-1798.


ML10

FROM SINGLE MOLECULES TO ORGANIZED STRUCTURES IN THIN POLYMER FILMS

M. STAMM, A. KIRIY

Leibnitz Institute for Polymer Research, Dresden, Germany

Virtually all knowledge of chemical processes has been deduced from ensemble measurements. This has led scientists to think of molecular processes as well-ordered sets of events. However, if one wants to know either the molecules are all the same or all different, one should simply look at the individual molecules one at a time and compare them. The direct observation of individual molecules overcomes limitations of ensemble measurements, while still permitting the determination of collective properties through the collection and statistical treatment of the data. Investigation of biological and synthetic macromolecules as individual entities is a newly emerging and promising area of research. However, single synthetic macromolecules are significantly less explored than biopolymers, while they offer a wide variabilty of chemical composition, architecture and functionalities, which can be designed by macromolecular chemistry. In that respect synthetic macromolecules can provide versatile building blocks for future molecular electronics.

This lecture will review our recent achievements in investigation of single adsorbed polymer molecules. In particular, visualization of macromolecules of various architecture in different conformations by atomic force microscopy will be in the focus of the first part of the presentation. We will demonstrate that AFM is a powerful tool for study of various processes at the level of individual macromolecules and is also a useful method for determination of molecular weight of polymers. Utilization of the single macromolecules in synthesis of nanoparticles of various shape and composition – metallic, semiconductive, organic and inorganic – will demonstrated in the second part of the talk (A. Kiriy, S. Minko, G. Gorodyska, M. Stamm, W. Jaeger. Nano Letters, 2002, 2, 881-885; A. Kiriy, A. Gorodyska, S. Minko, C. Tsitsilianis, W. Jaeger, M. Stamm, J. Am. Chem. Soc. 2003, 125, 11202.). Finally, we will report on our recent results in fabrication of nanodevices and nanosensors using individual macromolecules as positive templates (V. Bocharova, A. Kiriy, H. Vinzelberg, I. Mönch, M. Stamm, Angew. Chem. Int. Ed. 2005, 44, 6391. V. Bocharova, A. Kiriy, M. Stamm, F. Stoffelbach, R. Jérôme, C. Detrembleur, Small 2006, in press).