A newly built molecular beam scattering apparatus that utilizes a flat liquid jet allows us to experimentally probe the scattering dynamics of molecular beams from the surface of flat, microscopically thin jets of volatile liquid, and in turn, the highly chemically relevant gas-liquid interface. The scattered species are analyzed by a rotatable mass-spectrometer which provides mass, energetic, and angular selectivity. The capacity to rotate both the flat liquid jet and detector enables us to sample a large range of incident and outgoing angles. A tunable electron impact ionizer enables isomer-specific identification of the scattered species by measurement of ionization efficiency curves.

We have studied the evaporation and scattering of neon from a dodecane flat liquid jet, extracting relevant information on scattering and energetic distributions at various deflection angles. The latter gives us the ability to examine energy loss of the incident beam through kinematic models. The dynamics of reactive scattering events are at the forefront of our interests, leading us to future work focusing on more volatile solutions. For example, studying water-based systems such as CO₂ scattering from monoethanolamine (MEA) solution and SO₃ scattering from salty water will provide more insight onto water-based catalysis and atmospheric chemistry.

Systems studied:

Dodecane–neon

Dodecane–deuterium oxide

Dodecane–methane-d₄

Dodecane–ammonia-d₃

Farnesene–neon

Project members:

Madison Foreman

Steve Saric

Walt Yang

Schematic of the scattering machine

Microfluidic chip for flat jet production and representative liquid flat jet