title: Micellization of cetyltrimethylammonium bromide: effect of small chain Bola electrolytes.
abstract: Sodium dicarboxylates (or Bola salts) with methylene spacers 0, 2, 4, 6, 8, and 10 were studied in aqueous solution to investigate their influence on the micellization of cetyltrimethylammonium bromide (CTAB). Since bolas with spacer length ≤12 are known not to micellize in general, the herein used sodium dicarboxylates were treated as 2:1 amphiphilic electrolytes which reduced surface tension of water (except sodium oxalate with zero spacer) without self-association. Their concentration dependent conductance was also linear without breaks. The bolas affected the micellization of CTAB but acted like salts to decrease its CMC. Their combinations did not form bilayer aggregates as found in vesicles. Nevertheless, they synergistically interacted with CTAB at the air/water interface as revealed from Rosen's thermodynamic model. Hydrodynamic radius (Rh), Zeta-potential (ζ), and electrical double layer behavior of bola interacted CTAB micelles were assessed. From SANS measurements, micelle shape, shape parameters, aggregation number (Nagg), surface charge of the bola influenced CTAB micelles were also determined. NMR study as well supported the non-mixing of bolas with the CTAB micelles. They interacted in solution like "amphiphilic electrolytes" to influence the surface and micelle forming properties of CTAB.
authors.affiliation: Centre for Surface Science and §Indian Society for Surface Science & Technology, Department of Chemistry, Jadavpur University , Kolkata 700 032, India.
authors.forename: Animesh
authors.initials: A
authors.lastname: Pan
authors.forename: Pallabi
authors.initials: P
authors.lastname: Sil
authors.forename: Sounak
authors.initials: S
authors.lastname: Dutta
authors.forename: Prasanta Kumar
authors.initials: PK
authors.lastname: Das
authors.forename: Subhash Chandra
authors.initials: SC
authors.lastname: Bhattacharya
authors.forename: Animesh Kumar
authors.initials: AK
authors.lastname: Rakshit
authors.forename: Vinod Kumar
authors.initials: VK
authors.lastname: Aswal
authors.forename: Satya Priya
authors.initials: SP
authors.lastname: Moulik
mesh_terms: D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry*; D004573:Electrolytes / Q000737:chemistry*; D008823:Micelles; D008954:Models, Biological; D008958:Models, Molecular
chemical_list: D002593:Cetrimonium Compounds; D004573:Electrolytes; D008823:Micelles; D000077286:Cetrimonium