Nonlinear Rheology of Multiarm Star Chains
Bibliographic record
Abstract
In the linear viscoelastic regime, multiarm star chains having more than 24 arms bound by a soft core exhibit fast relaxation due to motion of individual arms and slow relaxation related to motion of the soft cores (structural rearrangement in a liquidlike order). In this regard, the multiarm stars are qualitatively similar to randomly dispersed polystyrene−polyisoprene (PS−PI) and polybutadiene−polystyrene (PB−PS) copolymer micelles, the former having rigid (glassy) PS cores and the latter with soft (rubbery) PB cores. However, the multiarm star PB chains and the copolymer micelles were found to exhibit significant rheological differences in the nonlinear regime possibly because of the differences in their core−arm (core−corona) compatibility and core softness. In long time scales, the nonlinear damping of the relaxation modulus measured for the multiarm star PB was much weaker than that for the micelles and somewhat similar to the damping of a critical gel. In contrast, the damping in short time scales was moderately stronger for the multiarm stars. A corresponding difference was observed for the viscosity under fast flow. These differences may be attributed to a strain-induced elastic coupling of the multiarm star chains: The soft core of the multiarm star, chemically identical to the arms, may become scarcer on application of large deformation to suck in some segments of neighboring star arms so as to preserve the segment density therein. Then, the multiarm star chains are elastically coupled/connected through these cores to form a huge transient network under large deformation, thereby increasing and decreasing the relaxation intensities in long and short time scales, respectively. This mechanism, being absent for the PS−PI and PB−PS micelles because of lack of the core−corona compatibility (as well as the core rigidity for the PS−PI micelles), would have led to the observed weakening and enhancement of the damping for the slow and fast processes of the multiarm stars.
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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".