Fluorescent Nanoparticles through Self‐Assembly of Linear Ionenes and Pyrenetetrasulfonate

Abstract

We investigated the association of linear cationic model polyelectrolytes with oppositely charged pyrenetetrasulfonate in aqueous solution. Water soluble ionenes were prepared via Menschutkin reaction from 1‐4‐diazabicyclo[2.2.2]octane (DABCO) and dibromoalkenes. UVVis results revealed that PY molecules bind to ionenes in a cooperative process due to π–π interaction. Size and structure of the particles vary in dependence of inter‐charge distance on the ionene backbone. Stable spherical dye–ionene assemblies with radii between 50 and 200 nm have been obtained with one polyelectrolyte (PD4), while this was not possible with a different polyelectrolyte (PD6) or in either case at polyelectrolyte excess. It was possible to deposit the fluorescent polyelectrolyte–dye aggregates onto mica surfaces.magnified image

Light‐Responsive Shape: From Micrometer‐Long Nanocylinders to Compact Particles in Electrostatic Self‐Assembly

“…Simple linear polyelectrolytes are highly suitable building blocks as they are readily available. Linear polyelectrolytes have been used to form assemblies according to this concept of electrostatic self‐assembly, up to now only with spherosymmetric shape though …”

Association of a Cylindrical Polyelectrolyte Brush with Tetravalent Counterions

“…After inter‐polyelectrolyte and polyelectrolyte–counterion complexes of linear polyelectrolytes have been investigated extensively,23–28 and solid state polyelectrolyte–surfactant complexes have been well‐known for a longer time,29–32 cylindrical polyelectrolyte brushes recently came into focus for self‐assembled ionically driven systems 33–41. Polyelectrolyte brush‐surfactant complexes have been studied in solution, showing a brush diameter increase and persistence length increase for a poly(vinylpyridine) based system,42 while surfactants induced helix formation of poly(lysine) brushes 43, 44.…”

Cost‐effectiveness of prostate cancer chemoprevention

“…Although polyelectrolytes as PDADMAC have been extensively applied in layer‐by‐layer self‐assembly, for example with various inorganic nanoparticles64, 65 or dyes,66–70 stable nano‐assemblies of PDADMAC or QPVP and dye molecules in solution have not been in focus yet. Only a few studies exist that consider the nanoscale structure of assemblies from linear flexible polyelectrolytes and oppositely charged dye molecules, but none with the goal to create switchable systems 71–74. Of special interest in the study presented here are the assembly sizes, stoichiometries and thermodynamic parameters before and after irradiation and in comparison to the previous investigation; that is, the influence of polyelectrolyte architecture and the closely associated question of the driving forces behind the light‐driven size change.…”