How strongly can calcium ion influence the hydrogen-bond dynamics at complex aqueous interfaces?
The author has performed three independent molecular dynamics computer simulations to examine the effects of counterion identity on hydrogen-bond dynamics in the enclosed water pool of anionic surfactant-based reverse micelles. The water-water hydrogen-bond lifetime in the reverse micelle (RM) with calcium ions is found to be longer than that in the RM with sodium or ammonium ions. The hydrogen bond between a polar head group and a water molecule, on the other hand, breaks but reforms most rapidly in the RM with calcium ions, indicating that there exists a strong competition between head group-counterion and head group-water interactions at such complex interfaces.
Senapati
Sanjib
S
Department of Biotechnology, Indian Institute of Technology, Madras, Chennai 600036, India. sanjibs@iitm.ac.in
D002118:Calcium / Q000737:chemistry*; D002245:Carbon Dioxide; D002412:Cations; D002627:Chemistry, Physical / Q000379:methods; D006859:Hydrogen / Q000737:chemistry; D006860:Hydrogen Bonding; D007477:Ions; D008823:Micelles; D008962:Models, Theoretical; D012984:Software; D012996:Solutions; D013499:Surface Properties; D013997:Time Factors; D014867:Water / Q000737:chemistry*
D002412:Cations; D007477:Ions; D008823:Micelles; D012996:Solutions; D014867:Water; D002245:Carbon Dioxide; D006859:Hydrogen; D002118:Calcium