Experiment: Nguyen Group_20210204_2-methylbut-3-ene-1,2-diol/Methyl nitrite_Hydroxyl radical_Ammonium sulfate
Experiment
Name: Nguyen Group_20210204_2-methylbut-3-ene-1,2-diol/Methyl nitrite_Hydroxyl radical_Ammonium sulfate
Date: 2021-02-04
Organization
Nguyen Group
Chamber
Tran's big bag of air
Experiment Set
1,2-dihydroxy isoprene (DHI)
Goals
Product & SOA formation study on 2-methylbut-3-ene-1,2-diol (1,2-DHI) + OH, seeded (ammonium sulfate), dry, trying to get the best conditions possible for any isomerization/autooxidation to occur (including high temperature, low OH / light)
Summary
The chamber was heated to 35˚C and all but two lights were removed from the chamber (~3% of max light flux). 1,2-DHI and CH3ONO were injected, AS was atomized, and the bag was allowed to mix and equilibrate, after which the lights were turned on and left on overnight (>24 h). The CIMS was ran out of reagent gas, so signals were pretty wonky after 6:00am on the second day.Experiment Details
Categories:
- Gas phase chemical reaction
Relative Humidity: 5
Seeded Experiment: Yes
Type of Seed: Ammonium sulfate
Initial Seed Concentration Value: 250
Seed Concentration Units: micrograms_per_cubic_meter
Fuchs Adjusted Surface Area:
Condensation sink rate coefficient: 5
Reaction type:
Oxidant Name: Hydroxyl radical
Initial Oxidant Concentration Value: 3e5 (molecules_per_cubic_centimeter)
RO2 Main Fate: Autoxidation/Isomerization
RO2 Lifetime: (Seconds)
Pressure: 755
Data Set plots
Experiment Set Details
Name: 1,2-dihydroxy isoprene (DHI)
Time format and units: HH:MM, local time
Description:
A series of experiments to investigate the gas-phase oxidation rate of 1,2-dihydroxy isoprene, its oxidation products via various RO2 pathways, and the effects of including seed (AS = ammonium sulfate) particles both on observed gas-phase products and on SOA formation.
Collaborators:
- Kelvin H Bates Harvard / UC Davis
Contacts
Principal investigator:
Tran B. Nguyen
Phone: 5307525987
E-mail: tbn@ucdavis.edu
OrcID: 0000-0001-9206-4359
Data Manager:
Kelvin H. Bates
E-mail: kelvinhbates@gmail.com
timeline_210204.csv
Timeline
| Time_local_HHMM | Action |
| 13:45 | Instruments on; chamber heating |
| 13:50 | SMPS on |
| 13:52 | DHI injection start |
| 13:57 | Atomizing start |
| 14:08 | CH3ONO injection start |
| 14:27 | Atomizing stop |
| 14:30 | Other injections stop; mixing air bursts |
| 15:30 | 2 lights on (~3%) |
| 16:05 | pause CIMS to reduce sampling frequency for overnight sampling |
| 9:00 | Start reducing temperature and shutting down |
Citations
Characterizations
(None)
Particle Loss Characterizations:
(None)
Vapor Loss Characterizations:
(None)
Chamber Details
Name: Tran's big bag of air
Volume in cubic meters: 10
Shape: Rectangular Prism
Surface area in cubic meters: 28
Flow Mode: Batch
Flow through rate in liters per minute:
Body Material: Teflon
Body thickness: 2
Replacement date:
Replacement frequency: As needed
Cleaning method:
Flushing with air
Flushing with air with UV lights on
Oxidation
o3 background: < 0.5 ppb
nox background:
Particle background in micrograms per cubic meter:
Air filtration method: Custom filtration canisters to remove NOx, hydrocarbons, water, particles, ozone, SOx from pressurized ambient air.
Mixing method: 1
Mixing method material: Pulsed air jets, manually actuated
Temparature Control: Yes
Temparature measurements recorded: Yes
Temparature range (min degrees celcius):
Temparature range (max degrees celcius):
Humidity Control: Yes
Humidity Measurements Recorded: Yes
Relative humidity range (min percent):
Relative humidity range (max percent):
Particle experiment capability: 1
Lights: Yes
Light source type(s):
UV broadband black lights (centered at 350 nm)
Supplemental information:
Additional Notes: 40-Watt, Osram/Sylvania 350nm black lights, 48” long, T12 fluorescent; 72 bulbs, 36 each on two facing walls, with UV-reflective siding on all walls. Lights are controlled via 6 panels (3 on the right wall - top, mid, bottom - and 3 equivalent on the left wall).