Solar polymeric

The facile, photoinduced valence isomerization of ethyl 1//-azepine-l-carboxylate to ethyl 2-azabicyclo[3.2.0]hepta-3,6-diene-2-carboxylatehas been studied as a potential solar energy storage system.101102 Unfortunately, the system proved to be inefficient due to build up of polymeric material during the thermally induced, exothermic retro-reaction. 

The deposition of CBD CdS as a junction layer for solar cell devices has proven to be a very successful industrially acceptable technique. Kessler et al.13 reported on copper indium gallium diselenide (CIGS) mini-modules (area = 16cm2) with a conversion efficiency of 16.6%, wherein CBD CdS was used as a junction layer. Basol et al.14 fabricated 9.3% active-area efficient thin-film flexible CuInSe2 (CIS) solar cells (specific power >1 kW/kg) on lightweight, flexible metallic, and polymeric (polymide-based) substrates using CBD CdS. 

Most synthetic and natural polymers degrade when exposed to solar ultraviolet (UV) radiation (1-5). In synthetic polymers degradation is generally caused by the presence of photosensitive impurities and/or abnormal structural moieties which are introduced during polymerization or in the fashioning of the finished products. The presence of groups such as ketones, aldehydes, peroxides and hydroperoxides are implicated in polymer degradation (1-5). 

Landi BJ, Castro SL, Ruf HJ, Evans CM, Bailey SG, Raffaelle RP (2005). CdSe quantum dot-single wall carbon nanotube complexes for polymeric solar cells. Solar Energy Mater And Solar Cells 87 733-746. 

Schubert M, Yin CH, Castellani M, Bange S, Tam TL, Sellinger A, Horhold HH, Kietzke T, Neher D (2009) Heterojunction topology versus fill factor correlations in novel hybrid small-molecular/polymeric solar cells. J Chem Phys 130 094703... 

These molecular assemblies are unfortunately not stable enough to construct practical solar energy conversion systems. Vesicles composed of polymerizable monomers (e.g., 4, 5) were polymerized to give polymeric vesicles having enhanced stability 25 26). 

The photoreduction of polymer pendant viologen by 2-propanol was reported to proceed by the successive two-electron transfer processes between the adjacent viologen units and the propanol which is a two-electron reducing agent44). Preferential formation of a dimeric cation radical of viologen observed was ascribed to the polymeric structure and the two-electron process. These fundamental studies on polymeric electron mediators contribute to the construction of solar energy conversion systems. 

As described above, polymeric materials provide specific microenvironment in solution which contributes much to construct solar energy conversion systems. Macrohetero-geneous systems constructed from polymers are of great value especially from the practical point of view. 

Apart from the possible use of polymerized vesicles as stable models for biomembranes (Sect. 4) there may be a variety of different applications. Polymerized surfactant vesicles have been proposed to act as antitumor agents on a cellular level33 in analogy to the action of the immune system of mammals against tumor cells 85). Polymerized vesicles open the door to chemical membrane dissymmetry 22) which in turn, may lead to enhanced utility in photochemical energy transfer84 (solar energy conversion, artificial photosynthesis). The utilization of unpolymerized lipo-... 

Reviews have already been published by J. H. Fendler on Polymerized Surfactant Vesicles 91 92,931 which refer to Novel Membrane Mimetic Systems , synthetic strategies leading to them and their characterization and potential utilization in various areas such as solar energy conversion and reactivity control. It is the intend of this appendix to bring the reader up to date on the state of the art of polymerized liposomes. 

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