Experiment: Ziemann_20071125_2,3,6,7-Tetramethyloctane/Methyl nitrite/Nitric oxide_Hydroxyl radical_DOS

Experiment

Name: Ziemann_20071125_2,3,6,7-Tetramethyloctane/Methyl nitrite/Nitric oxide_Hydroxyl radical_DOS
Date: 2007-11-25

Organization
Ziemann

Chamber
UC Riverside (APRC)

Experiment Set
Branched Alkane OH, High NOx

Goals
Determine SOA yield of OH radical oxidation of the VOC

Summary
Alkanes were reacted with OH radicals in the presence of NOx in a 5900 L PTFE environmental chamber filled with clean, dry air (<5 ppbv hydrocarbons, <1% RH) at ∼25 °C and atmospheric pressure. The reaction mixture contained ∼200-400 µg m-3 of dioctyl sebacate (DOS) seed particles added from an evaporation condensation aerosol generator and 1 (0.5 heptadecane), 10, and 10 ppmv alkane, methyl nitrite, and NO. Reactions were initiated by turning on blacklights to form OH radicals by methyl nitrite photolysis. The average OH radical concentration for 60 min of reaction was ∼3 × 107 cm-3 , and ∼50-85% of the alkane reacted.

Additional Notes
In order to determine the yield at every time internal, an assumed OH profile was calculated in line with modeling from Lim and Ziemann, 2009 (https://doi.org/10.1039/B904333K). This was used in combination with initial and final measurements of the alkane concentration made with Tenax injections onto a GC-FID. Mass concentrations from the SMPS were increased by a factor of 1.24 in line with observations made in Bakker-Arkema and Ziemann, 2021 (https://doi.org/10.1021/acsearthspacechem.1c00008).

Experiment Details

Categories:

  • Gas phase chemical reaction
  • Photolysis, any phase
  • Aerosol formation
  • Aerosol aging
Temperature: 25
Relative Humidity: 1
Seeded Experiment: Yes
Type of Seed: DOS
Initial Seed Concentration Value: 140
Seed Concentration Units: micrograms_per_cubic_meter
Fuchs Adjusted Surface Area:
Condensation sink rate coefficient: 1
Reaction type:
Oxidant Name: Hydroxyl radical
Initial Oxidant Concentration Value: 0 (molecules_per_cubic_centimeter)
RO2 Main Fate: NO
RO2 Lifetime: (Seconds)
Pressure: 740 Torr

Data Set plots
Choose a file: Choose the X-Axis:

Experiment Set Details

Name: Branched Alkane OH, High NOx
Time format and units: Minutes from start of reaction
Description:
Branched alkanes were oxidized by OH radicals in a high NOx environment. For each experiment, 1 ppmv of the alkane*, 10 ppmv methyl nitrite, and 10 ppmv NO. *The only exception is heptadecane, which was run at 0.5 ppmv. The following linear alkanes were used: 3,4-diethylhexane, 2-methylundecane, 2,3-dimethyldecane, 2,6-dimethyldecane, 2,3,6,7-tetramethyloctane, 2,2,4,4-tetramethyloctane, 2,2,4,6,6-pentamethylheptane, 4,4-dipropropylheptane, 2,3,3-trimethyldecane, 2,6,10-ttrimethyldodecane, n-butylcyclohexane, and n-deccylcyclohexane.

Collaborators:

Contacts

Principal investigator:

Paul J Ziemann
Phone: 3034929654
E-mail: paul.ziemann@colorado.edu
OrcID: 0000-0001-7419-0044

Data Manager:

Marla DeVault
E-mail: marla.devault@colorado.edu

Reactants

Reactant Compound type Concentration Concentration units
2,3,6,7-Tetramethyloctane (537765) 0.996 Parts Per Million
Methyl nitrite (12231)
  • Nitroalkane
10 Parts Per Million
Nitric oxide (145068)
  • NOx
10 Parts Per Million

2,3,6,7-tetramethyloctane_Timeline.csv Timeline

Time_Min Event Description
0 Lights on
56 Lights off

Characterizations
Light Flux Characterizations:
2008-03-01 (#44)
Particle Loss Characterizations:
(None)
Vapor Loss Characterizations:
(None)

Chamber Details

Name: UC Riverside (APRC)
Volume in cubic meters: 5.9
Shape:
Surface area in cubic meters: 3.3
Flow Mode: Batch
Flow through rate in liters per minute:
Body Material: Teflon
Body thickness:
Replacement date:
Replacement frequency:
Cleaning method: Flushing with air
o3 background:
nox background:
Particle background in micrograms per cubic meter:
Air filtration method:
Mixing method: 1
Mixing method material: Fan
Temparature Control: No
Temparature measurements recorded: No
Temparature range (min degrees celcius):
Temparature range (max degrees celcius):
Humidity Control: Yes
Humidity Measurements Recorded: Yes
Relative humidity range (min percent): 1
Relative humidity range (max percent): 100
Particle experiment capability: 1
Lights: Yes
Light source type(s): Blacklights
Supplemental information:
Additional Notes: