Experiment: Caltech Atmospheric Chamber_20201112_DECAMETHYLCYCLOPENTASILOXANE_Hydroxyl radical_Ammonium sulfate_C8


Name: Caltech Atmospheric Chamber_20201112_DECAMETHYLCYCLOPENTASILOXANE_Hydroxyl radical_Ammonium sulfate_C8
Date: 2020-11-12

Caltech Atmospheric Chamber

Near Bag 2017

Experiment Set
D5 Chamber Experiments

Measure SOA yield of D5

Performed in the Caltech Near Bag, initial NO of 84 ppb, used CH3NO2 (all others used H2O2)

Experiment Details


  • Aerosol formation
Temperature: 26.6
Relative Humidity: 5
Seeded Experiment: Yes
Type of Seed: Ammonium sulfate
Initial Seed Concentration Value:
Seed Concentration Units:
Fuchs Adjusted Surface Area:
Condensation sink rate coefficient: 5
Reaction type:
Oxidant Name: Hydroxyl radical
Initial Oxidant Concentration Value: variable (molecules_per_cubic_centimeter)
RO2 Main Fate: HO2
RO2 Lifetime: (Seconds)

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

Experiment Set Details

Name: D5 Chamber Experiments
Time format and units:
Decamethylcyclopentasiloxane (D5, C10H30O5Si5) is measured at ppt levels outdoors and ppb levels indoors. Primarily used in personal care products, its outdoor concentration is correlated to population density. Since understanding the aerosol formation potential of volatile chemical products is critical to understanding particulate matter in urban areas, the secondary organic aerosol yield of D5 was studied under a wide range of OH concentrations and exposures using both batch-mode chamber and continuously run flow tube experiments. These results were comprehensively analyzed and compared to two other secondary organic aerosol (SOA) yield datasets from literature. It was found that the SOA yield from the oxidation of D5 is extremely dependent on the OH concentration or exposure.


  • Sophia M Charan Caltech


Principal investigator:

John H Seinfeld
Phone: (626) 395-4635
E-mail: seinfeld@caltech.edu
OrcID: https://orcid.org/0000-0003-1344-4068

Data Manager:

Stephanie Kong
Phone: 626-395-3194
E-mail: wkong@caltech.edu


Reactant Compound type Concentration Concentration units

201112_NB_TimeLine.csv Timeline

Time (America/Los_Angeles) Action
11/12/2020 15:53:29 RHT/NOx/O3 on
11/12/2020 17:07:03 CIMS on
11/12/2020 17:20:50 SMPS on
11/12/2020 18:00:20 GC on
11/12/2020 18:56:00 Time background starts
11/12/2020 21:59:00 Lights on
11/13/2020 05:28:48 GC off
11/13/2020 05:43:40 DMA off
11/13/2020 05:50:26 CIMS off
11/13/2020 06:22:59 RHT/Nox/O3 off

Light Flux Characterizations:
Particle Loss Characterizations:
Vapor Loss Characterizations:

Chamber Details

Name: Near Bag 2017
Volume in cubic meters: 19
Shape: Rectangular Prism
Surface area in cubic meters: 41.8
Flow Mode: Batch
Flow through rate in liters per minute:
Body Material: Teflon
Body thickness: 50
Replacement date: 2017-08-08
Replacement frequency: As needed
Cleaning method: Flushing with air
o3 background:
nox background: 0.1
Particle background in micrograms per cubic meter: 0
Air filtration method: Custom Filter
Mixing method: 0
Mixing method material:
Temparature Control: Yes
Temparature measurements recorded: Yes
Temparature range (min degrees celcius): 20
Temparature range (max degrees celcius): 45
Humidity Control: Yes
Humidity Measurements Recorded: Yes
Relative humidity range (min percent): 5
Relative humidity range (max percent): 100
Particle experiment capability: 1
Lights: Yes
Light source type(s): UVA Black Lamps
Supplemental information: https://www.worldscientific.com/doi/abs/10.1142/9789813147355_0001
Additional Notes: