Development of Ion Speciation Plots for Three Promising Tertiary Amine–CO<sub>2</sub>–H<sub>2</sub>O Systems Using the pH Method and the <sup>13</sup>C NMR Method
Bibliographic record
Abstract
In this work, three promising tertiary amines—1-(2-hydroxyethyl)piperidine (1-(2-HE)PP), 3-(diethylamino)-1,2-propanediol (DEA-1,2-PD), and N -(2-hydroxyethyl)pyrolidine (1-(2-HE)PRLD)—were experimentally studied and the results presented in terms of p K a, the protonation calibration curves, and ion speciation plots. The p K a of these amines were determined in the temperature range of 294–320 K. The protonation calibration curves for the three amines were also developed based on 13 C NMR detection. In addition, ion (amine, amineH +, HCO 3 –, and CO 3 2– ) speciation plots for the three tertiary amines were developed at the temperature of 298 K, at the amine concentration of 1.0 M, over the CO 2 loading ranges of 0–0.897 mol CO 2 /mol amine for 1-(2-HE)PP, 0–0.915 mol CO 2 /mol amine for DEA-1,2-PD, and 0–0.927 mol CO 2 /mol amine for 1-(2-HE)PRLD by using the pH method, the 13 C NMR method, and the pH + 13 C NMR method. By comparing the ion (amine, amineH +, HCO 3 –, and CO 3 2– ) concentrations of the three tertiary amines obtained from these three methods, it can be concluded that each of these three methods could be used to develop the ion speciation plots of amine–CO 2 –H 2 O systems, but there are some significant differences between them.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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 source (direct Gemma or distilled Codex), 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".