Salinity tolerance, adsorption, and emulsification properties of nonylphenol alkyl sulphonates derived from bi-component linear alpha olefin

A series of bi-component nonylphenol alkyl sulphonate surfactants with different alkyl chains (C 12/ n -NPAS, n = 8, 10, 14, 16) were synthesized through sulphonation-alkylation-neutralization, using a mixture of linear alpha olefins as raw materials. The chemical structures were characterized by FTIR and ESI-MS. The purity values measured by the two-phase titration method were all higher than 0.96 g/g (96 wt%). The effects of the raw materials composition on salinity tolerance, adsorption, and emulsification properties were also investigated. There is marked adsorption amount variation for bi-component surfactants with a strong difference of carbon number of alkyl groups. The salinity tolerance of C 12/n -NPAS is about 40 g · L −1 of NaCl, and 0.65 g · L −1 of CaCl 2 . Compared with petroleum sulphonates (14 g · L −1 of NaCl, 0.08 g · L −1 of CaCl 2 ) and LAS (22 g · L −1 of NaCl, 0.37 g · L −1 of CaCl 2 ), NPAS surfactants show a low adsorption, excellent salinity tolerance, and emulsion stability.