Mass spectrometry is an analytical technique that identifies the chemical composition of a compound or sample based on the mass-to-charge ratio of charged particles. It is also used for elucidating the chemical structures of compounds. Mass spectrum of N-(3-(butylideneamino)propyl)-N,N-dimethylhexadecan-1- ammonium bromide (C16BT) was shown in Fig. 3 showed ion peaks at m/z: 460 (5%) (Corresponding to molecular weight) and at m/z: 462 (1%) (Corresponding to isotope peak). 3.2. Surface properties 3.2.1. Critical micelle concentration (CMC) Critical micelle concentration values of the prepared cationic surfactants have been obtained graphically by plotting the surface tension (g) of aqueous solutions of the prepared surfactants versus their bulk concentrations in mol/l at 25, 40 and 60 8C as showed in Figs. 4–6. By inspection data in Table 1, the CMC values of prepared cationic surfactants decrease by increasing the hydrophobic chain length this can be attributed to increasing the hydrophobicity and decreasing solubility thus free energy of system increase. So surfactant molecules aggregate into clusters (micelles), where the hydrophilic group are directed toward the solvent while the hydrophobic chain are directed toward the interior of micelle in a way to avoid energically unfavorable contact with the aqueous media, thereby reducing the free energy of system. Therefore, by increasing hydrophobic chain length, the tendency of surfactant molecule to form micelle increase thus CMC decreased. The decrease in CMC with rising temperatures is a result to increasing the temperatures causes a decrease in the hydration of hydrophilic group, which favor micellization (decrease CMC), also causes disruption of structured water surrounding the hydrFophobic group, an effect that disfavors micellization (increase CMC). Therefore, the relative magnitude of these two opposing effects determine whether the CMC increase or decrease over a particular temperature range [15]. From the data in Table 1, it is clear that CMC decrease by increasing temperatures, which implies that the magnitude of two factors is favoring micellization as indicated in Fig. 7.