Organization of nanoscale objects via polymer demixing

We present an extremely versatile method for the lateral organization of nano-scale objects (NOs) based on the phenomenon of polymer demixing. NOs are suspended in a soln. of two immiscible polymers, which is used to form a thin polymer film by spin coating. During spin coating the two polymers sep. to give a microphase structure, whose length scale depends on the exptl. conditions. The NOs spontaneously partition into one or other of the polymer phases resulting in their lateral organization. In this work, the organization of CdSe nanoparticles and fluorescent org. dyes was studied by fluorescence microscopy. The NOs were organized in the polymer film in stochastic patterns or in ordered designs on substrates pre-patterned by soft-lithog. techniques. Single-particle measurements, using confocal microscopy, showed that at low concns. there was little aggregation of the particles. [on SciFinder (R)]