title: Cationic gemini surfactants with cleavable spacer: chemical hydrolysis, biodegradation, and toxicity.
abstract: The paper describes synthesis and characterization of a new type of cationic gemini surfactant, which has dodecyl tails and a spacer that contains an ester bond. The nomenclature used to describe the structure is 12Q2OCO1Q12, with Q being a quaternary ammonium group and the numbers indicating the number of methylene or methyl groups. Due to the close proximity to the two quaternary ammonium groups, the ester bond is very stable on the acid side and very labile already at slightly alkaline conditions. The hydrolysis products are two single chain surfactants (i.e. 12Q2OH and 12Q1COOH) which are less surface active than the intact gemini surfactant. 12Q2OCO1Q12 was found to be readily biodegradable, i.e. it gave more than 60% biodegradation after 28 days. This is interesting because similar gemini surfactants but with ester bonds in the tails instead of the spacer, have previously been found not to be readily biodegradable. The gemini surfactant was found to be toxic to aquatic organisms (ErC50 value of 0.27 mg/l), although less toxic than the two hydrolysis products.
authors.affiliation: Chemical Engineering Department, Faculty of Engineering and Architecture, American University of Beirut (AUB), Beirut 1107 2020, Lebanon; Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
authors.forename: A R
authors.initials: AR
authors.lastname: Tehrani-Bagha
authors.affiliation: Department of Chemical and Biological Engineering, Chalmers University of Technology, SE-412 96 Göteborg, Sweden. Electronic address: kh@chalmers.se.
authors.forename: K
authors.initials: K
authors.lastname: Holmberg
authors.affiliation: AkzoNobel, Ecotoxicology & Environmental Testing Department, PO Box 9300, 6800 SB Arnhem, The Netherlands.
authors.forename: C G
authors.initials: CG
authors.lastname: van Ginkel
authors.affiliation: AkzoNobel, Ecotoxicology & Environmental Testing Department, PO Box 9300, 6800 SB Arnhem, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Kean
mesh_terms: D001673:Biodegradation, Environmental; D000460:Chlorophyta / Q000187:drug effects* / Q000254:growth & development; D006868:Hydrolysis; D008823:Micelles; D000644:Quaternary Ammonium Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity*; D045483:Rivers / Q000737:chemistry; D013501:Surface-Active Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism / Q000633:toxicity*
chemical_list: D008823:Micelles; D000644:Quaternary Ammonium Compounds; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical
keywords: Biodegradation; Cleavable; Gemini surfactant; Hydrolysis; Toxicity