Final Activity Report Summary - POLYAMPHI (Self-Organized Nanostructures of Amphiphilic Copolymers)
POLYAMPHI dealt with the novel nanostructures, which are generated by the self-organisation of a special kind of macromolecules, i.e. the amphiphilic block copolymers. Those polymers consist of at least one long segment, which is water-soluble or even carries charges (polyelectrolyte) and at least another segment, which is either insoluble in water or becomes insoluble under certain conditions, e.g. by raising the temperature. These polymers form various kinds of superstructures, both in bulk state and in solution, and very typical structures that are found in aqueous solution are micelles and vesicles. Micelles have a star-like structure in the range of tens of nanometres with a collapsed core built by the hydrophobic block and a diffuse corona built by the hydrophilic block. Vesicles are hollow objects in the range of hundreds of microns with a wall consisting of the collapsed hydrophobic block, which carries the water-soluble chains, similar to a liposome, on both sides. There is a number of interesting applications for such entities, including removal of pollutants from water or organ-targeted administering of drugs. They could also be used as nanosized reactors for chemical reactions or stabilisers of latex particles.
The project had the following various aims:
1. the synthesis of new polymer structures, which should be able to self-organise in a hierarchy of structures, as a model of biological objects. Advanced synthetic approaches were used, in particular living, i.e. radical, anionic or cationic, polymerisation techniques.
2. experiments which should prove the formation of a multitude of new structures and study their properties in solution or on an interface. Numerous experimental methods were used or developed, e.g. scattering (light, x-ray, neutron and neutron spin-echo), imaging (transmission and scanning electron microscopy, including cryo-techniques and scanning force microscopy) or spectroscopies, e.g. infrared (IR), ultraviolet (UV), two-dimensional nuclear magnetic resonance (2D-NMR), fluorescence and fluorescence correlation.
3. the utilisation of analytical theory and various techniques of simulation to help to understand the experimental phenomena and predict new structures.
13 research groups, including two within major industrial companies from seven European countries, with a total of 10 PhD students and 10 post-doctoral fellows collaborated for four years towards that end. Some of the most important project results were the following:
1. we synthesised a library of amphiphilic and bis-hydrophilic diblock copolymers different combinations, with well controlled and systematically varied block lengths, as well as polyelectrolytes of various topologies, such as stars, cylindrical and spherical brushes.
2. we achieved the generation of the so-called Janus particles, i.e. spherical, cylindrical or disc-like nanoparticles with a surface consisting of hemispheres or hemicylinders of different chemistry, e.g. polarity. The particles were generated via various pathways, such as self-organisation of ABC triblock terpolymers in bulk and cross-linking the B block and self-organisation of AB and CD diblock copolymers, where A and C were cationic and anionic, respectively, and B and D were different water-soluble polymers. Using atom layer deposition, these Janus particles served as templates for new hybrid structures.
3. the parameters determining the shape, size and dynamics of superstructures formed by block copolymers in aqueous solution were determined. Biohybrid vesicles were formed through interaction with channel proteins. Their use as a nanoreactor was demonstrated.
4. the interaction of micelles, brushes or stars with an ionic corona with polyelectrolytes of inverse charge led to various kinds of interpolyelectrolyte complexes, in particular to core-shell-corona structures.
5. reversible co-assembly of polymers was achieved by using ionic, hydrogen-bonding and metal-complex forces.
6. the self-assembly of rod-coil block copolymers in thin films yielded a large variety of highly ordered morphologies at multiple length scales.
The project had the following various aims:
1. the synthesis of new polymer structures, which should be able to self-organise in a hierarchy of structures, as a model of biological objects. Advanced synthetic approaches were used, in particular living, i.e. radical, anionic or cationic, polymerisation techniques.
2. experiments which should prove the formation of a multitude of new structures and study their properties in solution or on an interface. Numerous experimental methods were used or developed, e.g. scattering (light, x-ray, neutron and neutron spin-echo), imaging (transmission and scanning electron microscopy, including cryo-techniques and scanning force microscopy) or spectroscopies, e.g. infrared (IR), ultraviolet (UV), two-dimensional nuclear magnetic resonance (2D-NMR), fluorescence and fluorescence correlation.
3. the utilisation of analytical theory and various techniques of simulation to help to understand the experimental phenomena and predict new structures.
13 research groups, including two within major industrial companies from seven European countries, with a total of 10 PhD students and 10 post-doctoral fellows collaborated for four years towards that end. Some of the most important project results were the following:
1. we synthesised a library of amphiphilic and bis-hydrophilic diblock copolymers different combinations, with well controlled and systematically varied block lengths, as well as polyelectrolytes of various topologies, such as stars, cylindrical and spherical brushes.
2. we achieved the generation of the so-called Janus particles, i.e. spherical, cylindrical or disc-like nanoparticles with a surface consisting of hemispheres or hemicylinders of different chemistry, e.g. polarity. The particles were generated via various pathways, such as self-organisation of ABC triblock terpolymers in bulk and cross-linking the B block and self-organisation of AB and CD diblock copolymers, where A and C were cationic and anionic, respectively, and B and D were different water-soluble polymers. Using atom layer deposition, these Janus particles served as templates for new hybrid structures.
3. the parameters determining the shape, size and dynamics of superstructures formed by block copolymers in aqueous solution were determined. Biohybrid vesicles were formed through interaction with channel proteins. Their use as a nanoreactor was demonstrated.
4. the interaction of micelles, brushes or stars with an ionic corona with polyelectrolytes of inverse charge led to various kinds of interpolyelectrolyte complexes, in particular to core-shell-corona structures.
5. reversible co-assembly of polymers was achieved by using ionic, hydrogen-bonding and metal-complex forces.
6. the self-assembly of rod-coil block copolymers in thin films yielded a large variety of highly ordered morphologies at multiple length scales.