Long-chain polymerizable diacetylenic

Recently, the Langmuir-Blodgett (LB) technique has been recognized as a useful way of tailoring thin films of molecular thickness. Interest in the LB technique has led to a number of investigations of different types of materials. For example, the classic long-chain fatty acids and alcohols as well as polymerizable molecules, e.g. diacetylenic acids [211-213], aromatic hydrocarbons, e.g. substituted anthracenes [214, 215], TCNQ radical anion salts [216, 217] and charge transfer complexes [218-220] and dye substances can now all be produced as monomolecular layers. 

Since cholesterol is an important component of many biological membranes mixtures of polymerizable lipids with this sterol are of great interest. In mixed monolayers of natural lipids with cholesterol a pronounced condensation effect , i.e. a reduction of the mean area per molecule of phospholipid is observed68. This influence of cholesterol on diacetylenic lecithin (18, n = 12), however, is not very significant (Fig. 32). Photopolymerization indicates phase separation in this system. Apparently due to the large hydrophobic interactions between the long hydrocarbon chains of... 

Some substimted diacetylenes (R-C=C-CMI -R, hereinafter referred to as DA) constitute a class of crystals polymerizable in the solid state [1]. One may thus obtain large single crystals, built of poly diacetylene (PDA) chains parallel to one another. A pronounced anisotropy of the systems, due to the presence of long TC-conjugated chains, resulted in an interest concerning electrical and opticd properties of DA [2,3]. Much less attention has been paid to studies of their dielectric properties [4-6]. 

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