title: Area per surfactant molecule values of gemini surfactants at the liquid-hydrophobic solid interface.
abstract: Areas per surfactant molecule at the liquid/hydrophobic solid (A(LS)) and the liquid/air (A(LA)) interface as a function of the spacer length are reported for cationic gemini surfactants having (CH2)n spacer s. A(LA) increases with increasing spacer length up to 6-8 CH2 groups in the spacer and then levels off. A(LS) values indicate a more closely packed arrangement of the surfactant molecules than that at the liquid/air interface. Comparison of A(LA) and A(LS) values indicates that the surfactant molecules at the liquid/hydrophobic solid interface are almost three times as closely packed as those at the liquid/air interface. A comparison of the experimental values of the area per surfactant molecule at both interfaces was made with those calculated from dimensions of the surfactant molecule in vacuo.
authors.affiliation: Department of Chemical Theory of Drugs, Faculty of Pharmacy, Comenius University, Kalinciakova 8, SK-83232 Bratislava, Slovakia. pisarcik@fpharm.uniba.sk
authors.forename: Martin
authors.initials: M
authors.lastname: Pisárcik
authors.forename: Milton J
authors.initials: MJ
authors.lastname: Rosen
authors.forename: Mária
authors.initials: M
authors.lastname: Polakovicová
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Devínsky
authors.forename: Ivan
authors.initials: I
authors.lastname: Lacko
mesh_terms: D000388:Air; D002412:Cations / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D008958:Models, Molecular; D012997:Solvents / Q000737:chemistry; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D002412:Cations; D012997:Solvents; D013501:Surface-Active Agents