Occlusion of Polyaromatic Compounds in Asphaltene Precipitates Suggests Porous Nanoaggregates
Bibliographic record
Abstract
This study examined the occlusion of two polyaromatic hydrocarbons (PAHs) (pyrene and phenanthrene) in asphaltene precipitates. To test for occlusion inside the nanoaggregates, a toluene solution of asphaltene and each of these aromatic compounds was allowed to equilibrate and mix for 2 days to enable penetration into the asphaltene nanoaggregates and then the asphaltenes were precipitated with n -pentane, filtered, washed, and dried. To test for trapping and adsorption outside the nanoaggregates during precipitation, a solution of asphaltene in toluene was mixed with a solution of aromatic compound in toluene and n -pentane, giving immediate precipitation, then allowed to equilibrate overnight, then filtered, washed, and dried. The PAHs in the asphaltene precipitates were determined quantitatively by gas chromatography using a high-temperature simulated distillation instrument. Pyrene and phenanthrene, which are normally soluble in the toluene– n -pentane solutions, were detected in the asphaltene precipitates at up to 6 wt % concentration. Trapping of PAHs outside of the nanoaggregates during precipitation gave 7–14 times less of the PAHs in the solid precipitate. This study shows that asphaltene aggregates can interact significantly with PAHs. The results are consistent with the presence of open porous asphaltene nanoaggregates in solutions, such as toluene.
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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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".