laser-based techniques to explore atmospheric chemical ... · laser-based techniques to explore...

Research in the Kidwell Group

Office: ISC 1287; Lab: ISC 1243; Email: nmkidwell@wm.edu

Laser-Based Techniques to Explore Atmospheric Chemical Reactions

9/21/2017 1

Kidwell Group Fall 2017

College of William and Mary, Kidwell Group Research Description

9/21/2017 2

The Laser Lab

College of William and Mary, Kidwell Group Research Description

Aerosol Formation

College of William and Mary, Kidwell Group Research Description 3

[IPCC, 2013]Kulmala, M., Science, 2003, 302, 1000

College of William and Mary, Kidwell Group Research Description 4

Atmospheric Chemistry in the Kidwell Research Group

Marine Chemistry Planetary Atmospheres

All three projects are

investigating the first

few nucleation events

towards aerosol

formation under

different conditions

Urban Tropospheric Chemistry

College of William and Mary, Kidwell Group Research Description 5

Our Experimental Tool Kit

Sample/ArPump

Laser

Probe

Laser Townsend et al., Rev. Sci. Instrum. 2003 74, 2530

Eppink et al., Rev. Sci. Instrum. 1997 68, 2477

College of William and Mary, Kidwell Group Research Description 6

Anthropogenic Emissions in Urban Tropospheres

Lin, P., Phys. Chem. Chem. Phys., 2015, 17, 23312

Brown Carbon Molecules

Many classes of BrC molecules with many isomers

Fossil Fuels

Biofuels/Biomass Burning

College of William and Mary, Kidwell Group Research Description 7

Near UV Photodissociation of NitrophenolsE

ner

gy

Ground

State

Excited

State

355

nm

Pu

mp

Reaction Coordinate

NO

UV

Pro

be

Probing NO Q1(30.5)o-Nitrophenol + hn → Hydroxyphenoxy + NO

College of William and Mary, Kidwell Group Research Description 8

Biogenic Emissions from Oceans/Bodies of Water

Biomaterial

Halocarbons,

Amino Acids

Sulfur

Compounds

Bimolecular

Reaction

+hν+H2O,

NH3, etc.

Phytoplankton

Solar

Photolysis

College of William and Mary, Kidwell Group Research Description 9

Ozone Depletion from Halocarbon Photochemistry

CH2BrI + hn → CH2Br + I/I*

College of William and Mary, Kidwell Group Research Description 10

Ozone Depletion from Halocarbon Photochemistry

CH2BrI + hn → CH2Br + I/I*Probing I Probing I*

College of William and Mary, Kidwell Group Research Description 11

Ozone Depletion from Halocarbon Photochemistry

CH2BrI + hn → CH2Br + I/I*Determination of the

Bond Dissociation Energy (D0)

College of William and Mary, Kidwell Group Research Description 13

Planetary Atmospheres: Cassini’s Grand Finale Sept. 15, 2017

nasa.gov

College of William and Mary, Kidwell Group Research Description 14

Planetary Atmospheres: Models for Earth’s Atmosphere

College of William and Mary, Kidwell Group Research Description 15

Student Research Activities & Involvement

En

erg

y

S0

S1

35

5 n

m

Reaction Coordinate

UV

Probe

355 nm

Pump

Students will learn:

• Instrumentation building, troubleshooting

• Operate lasers and equipment to run experiments

• Computational chemistry and modeling

College of William and Mary, Kidwell Group Research Description 16

Kidwell Group

Currently 11 Students in the Group

• 1 Graduate Student: Jacob Blackshaw

• 6 Seniors: Annalise Ajmani, Changen Pan,

Wade Fritzeen, Sam Zhang,

Joseph Lee, Chandan Reddy

• 1 Junior: Robert Korb

• 2 Sophomores: Naa-Kwarley Quartey,

Sarah Chen

• 1 High School Student: Lehman Montgomery

• Interested in taking Freshmen,

Sophomores, or Juniors