Table 3.

Grouped atomic partial charges for free and bound surfactants calculated by DFT at B3LYP level of theory and 6–311 + + G** basis set^a.

Surfactant molecule	Head-group	α-group	α-group + alkyl tail	Net charge
Free surfactants (no solvation effect)
SDS	−1.258	+0.300	+0.258	−1
OG	−0.368	+0.198	+0.368	0
HPS	−1.000/+0.812	+0.063	+0.188	0
CTAB	+0.738	+0.044	+0.262	+1
Surfactants bound to solvated BSA protein
SDS	−1.242	+0.418	+0.399	−0.843
OG	−0.570	−0.504	+0.404	−0.166
HPS	−0.971/+0.649	+0.260	+0.400	+0.078
CTAB	+0.772	−0.021	+0.063	+0.835

^aHuibers⁴⁷ included α group as part of the head-group whereas others^48–50 included α group as part of the tail-group.