Investigation of Polymerizable Amphiphiles in Monolayers

Various states can be seen in the monolayer in analogy to pV-diagrams of three-dimensional systems at low pressures a gas analogous phase (a) can be formed which obeys a two-dimensional gas law. Compression leads to an expanded or liquid 

The measurement of surface pressure/area isotherms provides a method for studying the influence of parameters such as temperature, head group charge and size, alkyl chain length, and pH on membrane properties. The effect of head group bulkiness on surface pressure/area isotherms of polymerizable lysophospholipid analogs is illustrated in Fig. 7 36). 

A decrease in occupied area of the head group results in an increase in packing density of the molecules (45) exhibits only an expanded phase, (46) both a liquid and a solid-like phase, and (47) forms only a condensed film. Monolayer properties of many natural phospholipids and synthetic amphiphiles are described in the literature37 38. Especially the spreading behaviour of diacetylenic phospholipids at the gas-water interface was recently described by Hupfer 120). 

Apart from the characterization of lipids in monolayers, several other examples for the versatility of this method have been described. Gorter and Grendel postulated 

The correlation of monolayer properties and spherical membranes (liposomes, cells) has been discussed by Blume 44). 

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