Cationic lamellar liquid crystalline morphologies decrease the rate of hydrolysis of a series of 4-substituted benzylidene t-butylamine N-oxides compared to aqueous solutions. Rate constants for the aqueous acid hydrolysis decrease as the electron releasing effect increases and they are linear when plotted against σ+-substituent constants. Rho-values indicate a less sensitive reactivity series than the benzoic acids and a more sensitive reactivity in lamellar solvents. Reaction rates for the series in the latter solvent parallel the hydrophobic substituent constants. Three different lamellar morphologies were identified in the aqueous surfactant systems.