Dr. Castner's expertise is in the area of physical chemistry of condensed phases. His experimental expertise is focused on ultrafast laser spectroscopy, photophysics and photochemistry, aqueous polymer solutions, aggregates in solution, drug delivery, and ionic liquids. His recent work has focused on the development and physical characterization of room-temperature ionic liquids. Recently he became one of the editors for the Journal of Chemical Physics, published by the American Institute of Physics.