Langmuir and Langmuir−Blodgett Films of Mixed Asphaltene and a Demulsifier
Bibliographic record
Abstract
Asphaltene was extracted from Athabasca oil sands bitumen with n -heptane. The extracted maltene-free asphaltene was characterized for physicochemical properties through molecular weight, chemical composition, and functional group analysis. Monolayer characteristics of mixtures of asphaltene and a polymeric demulsifier were studied using a Langmuir interfacial trough at air−water and heptol−water interfaces through measurements of pressure−area and relaxation isotherms (“heptol” refers to a solvent mixture of hep tane and tol uene). Single-layer Langmuir−Blodgett (LB) films from monolayers of mixed asphaltene and demulsifier were deposited on silicon wafers at air−water and heptol−water interfaces. The deposited LB films were characterized by atomic force microscopy (AFM) imaging and contact angle measurements. Asphaltene forms nanoaggregates at both air−water and heptol−water interfaces. Asphaltene monolayers at a heptol−water interface are more compressible than those at an air−water interface and show little hysteresis. The presence of a demulsifier in a mixed monolayer renders the monolayer more compressible at both air−water and heptol−water interfaces. The asphaltene and demulsifier aggregates follow ideal mixing behavior at both air−water and heptol−water interfaces. AFM images of deposited monolayers reveal the presence of nanosize aggregates. The presence of demulsifier in an asphaltene monolayer can reduce the mechanical strength of the asphaltene monolayer as indicated by reduced rigidity with increasing demulsifier content in the compressibility plot.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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 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".