Surfactant-induced surface freezing at the alkane-water interface

Lei, Q.; Bain, C.D.

Abstract

Long-chain alkanes exhibit surface freezing at the alkane-air but not the alkane-water interface. Ellipsometry and surface tensiometry are used to show that a simple cationic surfactant, hexadecyltrimethylammonium bromide (CTAB), can induce surface freezing at the tetradecane-water interface even when present in mole fractions as low as 0.1. The surface-freezing temperature Ts is a linear function of the interfacial excess of CTAB. The excess surface entropy below Ts, S = –0.76±0.02 mJ K–1 m–2, is consistent with a rotator phase. Ellipsometry provides strong evidence for a frozen monolayer in which the chains are oriented near the surface normal.

Citation

Lei, Q., & Bain, C. (2004). Surfactant-induced surface freezing at the alkane-water interface. Physical Review Letters, 92(17), https://doi.org/10.1103/physrevlett.92.176103

• Journal Article Type: Article
• Publication Date: Apr 30, 2004
• Deposit Date: Apr 20, 2007
• Journal: Physical Review Letters
• Print ISSN: 0031-9007
• Electronic ISSN: 1079-7114
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 92
• Issue: 17
• DOI: https://doi.org/10.1103/physrevlett.92.176103
• Public URL: https://durham-repository.worktribe.com/output/1551049