The heterogeneous reaction of isoprene and kaolinite.

Date of Award


Document Type



College of Liberal Arts

Degree Name

Bachelor in Arts


Isoprene is the most abundant biogenic volatile organic compound (BVOC) in the Earth's atmosphere with emissions levels second only to methane. Once in the atmosphere, isoprene can undergo oxidation reactions and yield products that condense to form secondary organic aerosols (SOA), however there is still uncertainty over these processes. For example, there is still a discrepancy between model estimations and field measurements of isoprene concentration, especially over forest canopies. We suggest the reactive uptake of isoprene on mineral solids in soil as a possible sink. A laminar flow reactor was constructed to study the heterogeneous reaction of isoprene and kaolinite. The isoprene and kaolinite reaction produced adsorbed organic compounds that are suggested to be 2-c-methyl-eryhtritol and possibly the 2-methylthreitol, isomers of the 2-methyl tetrol and a component detected in aerosols. Kinetic analysis with the use of a laminar flow reactor provided an initial effective reactive uptake coefficient 1.3x10-4 for the heterogeneous reaction of isoprene and kaolinite under dry conditions. Further analysis under relative humidity is required to determine atmospheric relevance. If uptake coefficients remain on the same order of magnitude under humidified conditions, then this reaction would be considered a significant atmospheric process. (What follows is an illustration of a heterogeneous reaction of isoprene and kaolinite which produces the 2-methyl tetrol isomers.)