Effect of hydrophilic and hydrophobic group types

Hydrophobic tail groups are generally long-chain hydrocarbon residues [CH3 (CH2) —] including such different structures as  

4 Alkylnaphthalene residues (C3 and greater-length alkyl groups) 

5 High-molecular-weight propylene oxide polymers (polyoxypropylene glycol derivatives) 

The introduction of branching or unsaturation into the hydrophobic tail group increases the solubility of the surfactant in water or in organic solvents (compared to the straight-chain, saturated isomer), decreases the melting point of the surfactant, causes looser 

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