Atmospheric Chemistry of Perfluorinated Carboxylic Acids: Reaction with OH Radicals and Atmospheric Lifetimes
Bibliographic record
Abstract
Relative rate techniques were used to study the kinetics of the reactions of OH radicals with a homologous series of perfluorinated acids, F(CF 2 ) n COOH ( n = 1, 2, 3, 4), in 700 Torr of air at 296 ± 2 K. For n > 1, the length of the F(CF 2 ) n group had no discernible impact on the reactivity of the molecule. For n = 1, k (OH + F(CF 2 ) n COOH) = (9.35 ± 2.08) × 10 -14 cm 3 molecule -1 s -1 . For n = 2−4, k (OH + F(CF 2 ) n COOH) = (1.69 ± 0.22) × 10 -13 cm 3 molecule -1 s -1 . Dimerization constants for 2F(CF 2 ) n COOH = (F(CF 2 ) n COOH) 2 were determined to be 0.32 ± 0.03 Torr -1, 0.30 ± 0.03 Torr -1, 0.41 ± 0.04 Torr -1, and 0.46 ± 0.05 Torr -1 for n = 1, 2, 3, 4, respectively. Atmospheric lifetimes of F(CF 2 ) n COOH with respect to reaction with OH radicals are estimated to be approximately 230 days for n = 1 and 130 days for n > 1. Reaction with OH radicals is a minor atmospheric fate of F(CF 2 ) n COOH. The major atmospheric removal mechanism for F(CF 2 ) n COOH is believed to be wet and dry deposition which probably occurs on a time scale of the order of 10 days.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".