Wall Slip of Tridisperse Polymer Melts and the Effect of Unentangled versus Weakly Entangled Chains
Bibliographic record
Abstract
We characterized wall slip of tridisperse linear 1,4-polybutadiene on a silicon wafer in a parallel plate shear cell and tracer particle velocimetry. Tridisperse mixtures of fixed weight-average molecular weight M w and varying number-average molecular weight M n were prepared from nearly monodisperse polybutadienes. Their steady state slip behavior was examined at shear rates over the range of ∼0.1–15 s –1 . The results show that the slip behavior in the transition regime depends on M n at constant M w . This study also revealed that weakly entangled and unentangled chains in the mixtures influence wall slip differently: mixtures containing moderate amounts of weakly entangled chains exhibited enhanced slip while those containing unentangled chains did not. We explain this observation using the tube theory through the slip disentanglement mechanism proposed by Brochard and de Gennes in 1992 and conclude that the slip behavior is changed because of the force balance between the mobile and adsorbed chains and the reduced entanglement density and coil stiffness related to the incorporation of short chains of different lengths.
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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".