Thin film synthesis

Linear and nonlinear optical properties of a class of polydiacetylenes that can be grown as large area and controlled thickness thin films have been investigated. This involved an integrated research effort including monomer synthesis, thin film growth and new measurement techniques. 

Synthesis, thin film and tape 18, 17.3,10.2,5 Ba2Ca2Cu,09Tl TlBa2Ca2Cu,09... 

Polyacetylenes. The first report of the synthesis of a strong, flexible, free-standing film of the simplest conjugated polymer, polyacetylene [26571-64-2] (CH), was made in 1974 (16). The process, known as the Shirakawa technique, involves polymerization of acetylene on a thin-film coating of a heterogeneous Ziegler-Natta initiator system in a glass reactor, as shown in equation 1. 

In most of the studies discussed above, except for the meta-linked diamines, when the aromatic content (dianhydride and diamine chain extender), of the copolymers were increased above a certain level, the materials became insoluble and infusible 153, i79, lsi) solution to this problem with minimum sacrifice in the thermal properties of the products has been the synthesis of siloxane-amide-imides183). In this approach pyromellitic acid chloride has been utilized instead of PMDA or BTDA and the copolymers were synthesized in two steps. The first step, which involved the formation of (siloxane-amide-amic acid) intermediate was conducted at low temperatures (0-25 °C) in THF/DMAC solution. After purification of this intermediate thin films were cast on stainless steel or glass plates and imidization was obtained in high temperature ovens between 100 and 300 °C following a similar procedure that was discussed for siloxane-imide copolymers. Copolymers obtained showed good solubility in various polar solvents. DSC studies indicated the formation of two-phase morphologies. Thermogravimetric analysis showed that the thermal stability of these siloxane-amide-imide systems were comparable to those of siloxane-imide copolymers 183>. 

Husein, F., Imad, Zhou, YuanZhong, Li, Fan, Ryne, C., AUen, Chung Chan, Jacob, I., Kleiman, Yu, Gudimenko, and Clark, V, Cooper, Synthesis of Carbon Nitride Thin Film by Vacuum Arcs, Mater. Sci. Eng., A, Vol. 209,1996, pp. 10-15. 

Tessier, P. Y., Pichon, L., VUlechaise, P, Linez, P., Angleraud, B., MubumbUa, N., Fouquet, V, Straboni, A., Milhet, X., and Hildebrand, H. F., Carbon Nitride Thin Films as Protective Coatings for Biomaterials Synthesis, Mechanical and Biocompatibility Characterizations, Diamond Relat. Mater, Vol. 12,2003,pp. 1066-1069. 

The synthesis of thin films of organic conducting polymers on a nanometer scale is one of the challenges of nanotechnology. Electrochemical poly-... 

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