Bond length, hydrophobic groups

The maximum amount of water solubilized into hydrocarbon solvents by ionic surfactants appears to increase with increase in the concentration of the surfactant, the valence of the counterion, and the length of the alkyl chain (Kon-no, 1971b) and with the introduction of double bonds into the hydrophobic group (Demchenko, 1971). Straight-chain compounds appear to solubilize less water than branched-chain ones, possibly because the former form micelles that are more compact and rigid than the latter (Frank, 1969 Kon-no, 1971c). 

It is a simple matter to estimate the volumes of hydrophobic groups from published density data for alkanes (normal and fluori-nated) and poly dimethyl siloxanes [4, 5, 34]. One simply sums the group volumes (see Table 3). Similarly, the maximum length of the hydrophobic group can be calculated from known bond lengths. Thus, the maximum micelle radius and hence the limiting a values for the various aggregates can be calculated. Note that there are small dif-... 

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