title: Water-mediated aggregation of 2-butoxyethanol.
abstract: Water plays an important role in mediating hydrophobic interactions, and yet open questions remain regarding the magnitude, and even the sign, of water-mediated contributions to the potential of mean force between a pair of oily molecules dissolved in water. Here, the water-mediated interaction between 2-butoxyethanol (BE) molecules dissolved in water is quantified using Raman multivariate curve resolution (Raman-MCR), molecular dynamics (MD) simulations, and random mixing (RM) predictions. Our results indicate that the number of contacts between BE molecules at concentrations between 0.2 M and 1 M exceeds RM predictions, but is less than some MD predictions. Moreover, the potential of mean force between BE molecules in water has a well depth that is shallower than the direct interaction between 1-ethoxybutane chains in the gas phase, and thus the water-mediated contribution to BE aggregation is repulsive, as it pulls BE molecules apart rather than pushing them together.
authors: Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA. bendor@purdue.edu.
authors: Shannon R
authors: SR
authors: Pattenaude
authors: Blake M
authors: BM
authors: Rankin
authors: Kenji
authors: K
authors: Mochizuki
authors: Dor
authors: D
authors: Ben-Amotz