Hygroscopicity Study of Aerosolized Amino Acids

During the summer of 2023 I worked alongside Professor Tim Raymond of the Chemical
Engineering department on a research project concerning aerosols. This specific experiment used
both the Cloud Condensation Nuclei Counter (CCNC-100 by DMT) and the Scanning Mobility
Particle Sizer (SMPS, TSI Inc) to count and characterize a series of aerosols which were made in
the laboratory. There were six total compounds which were tested to determine their behavior as
an aerosol. The six compounds were selected based on previously observed behavior and
activity.
First, the individual compounds were made into a solution and aerosolized, which
allowed for its particle size distribution and particle counts to be recorded for later comparison.
Second, two compounds were selected and mixed into one solution. After this solution was made
it would then be aerosolized and run through the CCNC and SMPS to record the particle size and
counts of the mixture. This process was then repeated for three compounds mixed into a singular
solution. Thirdly, two compounds were chosen and made into separate solutions. These separate
solutions were aerosolized and then mixed in a chamber. This gaseous mixture was run though
the CCNC and SMPS to collect the particle size and count data. After all of this data was
collected, it was analyzed and compared using software written by the department for aerosol
analysis. Each of these trials gave a value denoted as Kappa, which was a measure of how active
a compound or mixture was. This Kappa value, the average particle size, and particle count was
then compiled and compared. This set of values was the ultimate goal of the experiment this
summer.