We present an explicit water molecular dynamics simulation of dilute solutions of model alkyltrimethylammonium surfactant ions (number of methylene groups in the tail is 3, 5, 8, 10, and 12) in mixture with NaF, NaCl, NaBr, and NaI salts, respectively.The copyright/E model is used to describe water molecules.Results Greens of the simulation at 298 K are presented in form of the radial distribution functions between nitrogen and carbon atoms of CH2 groups on the alkyltrimethylammonium ion, and the counterion species in the solution.The running coordination numbers between carbon atoms of surfactants and counterions are also calculated.
We show that I- counterion exhibits the highest, and Ball - Bat - Fastpitch F- the lowest affinity to "bind" to the model surfactants.The results are discussed in view of the available experimental and simulation data for this and similar solutions.