Understanding Adsorption of Violanthrone-79 as a Model Asphaltene Compound on Quartz Surface Using Molecular Dynamics Simulations
Bibliographic record
Abstract
A series of molecular dynamics simulations were performed to investigate the adsorption of violanthrone-79 (VO-79) as a model asphaltene compound on quartz surface in different organic solvents (n-heptane, toluene, and heptol with three different n-heptane/toluene volume ratios). Our simulations demonstrated that the type of solvent had a great impact on the kinetics of adsorption, such as the adsorption rate and final adsorption amount. However, the equilibrium modes of adsorption were similar: both monomer and aggregate adsorptions were observed regardless of the n-heptane and toluene contents. With monomer adsorption, the polyaromatic core (PAC) of VO-79 was merely parallel to the surface, whereas the PACs showed two types of orientations in aggregate adsorption—parallel and slant—with the majority of them slant to the surface, maintaining π–π stacking between neighboring PACs. Energetic analyses showed that the adsorption was driven primarily by van der Waals forces, accompanied by electrostatic interactions, hydrogen bonding, and free energy of solvation. The results reported here provide valuable insights at the molecular level into the mechanistic understanding of asphaltene adsorption on mineral surfaces in organic media.
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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".