Self-assembly casting methods

Several polymer/polyelectrolyte-nanocrystal hybrid devices have been fabricated seeking to exploit the electro and photoluminescent properties of such material [179-188]. Device fabrication in all these cases is by low-cost self-assembly based techniques. These devices utilize thin films of these hybrids obtained either by multilayer deposition or drop/spin casting methods. Thus, solar cells have been made from poly(2-hexylthiophene)-CdSe nanorod multilayers, lasers from drop cast films of CdSe-titania composites and an infrared emitter from multilayers... 

Kim et al. have developed a solution-phase synthesis method of ultralarge GO sheets involving pre-exfoliation of graphite flakes. Such large GO sheets spontaneously form lyotropic nematic phase at a very low concentration in water [125]. They produced self-assembled brick-Uke GO nanostmctures by simple casting of GO dispersions and drying in ambient conditions. These free-standing GO papers... 

Devices based on composites of nanocrystals with polymers or polyelectrolytes have been fabricated to exploit electroluminescent and related properties of nanocrystalline media. These devices utilize thin films of composites obtained by layer-by-layer deposition using self-assembly, drop-casting, or spin-casting methods. 

Smalley and coworkers sought to employ self-assembly to fabricate CNT-based electronic devices, where individual SWNTs were deposited on chemically functionalized nanolithographic patterns." This method should enable the creation of nanotube-based circuits and structures according to a predesigned pattern. Prior to this approach, it was common for nanotubes to be deposited on an electrode array by either random deposition (i.e., drop casting) or using probe microscopy (AFM or STM) to position CNTs on the electrode. Their approach is an example of using carboxylated CNTs in noncovalent interactions. 

Under the right concentrations, polymer colloids can self-assemble to form close-packed hexagonal films. Simple drop-casting methods enable the formation of large arrays of hexagonally packed particles, which provide a very simple but effective template through which to deposit materials to form patterns. The interstices between colloidal particles are small, approximately triangular holes. 

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