Correlations between the Viscoelastic Behavior of Pyrene-Labeled Associative Polymers and the Associations of Their Fluorescent Hydrophobes
Bibliographic record
Abstract
The viscoelastic behavior of a series of three pyrene-labeled hydrophobically modified alkali swellable emulsion copolymers (Py-HASEs) was investigated. All Py-HASEs thickened the aqueous solutions with viscosities orders of magnitude larger than that of a HASE control which displayed no pyrene hydrophobe. This fact demonstrated that the pyrene molecule is a good hydrophobe for associative thickeners such as HASEs. The Py-HASE solutions exhibited shear thinning, whose magnitude was found to increase with increasing pyrene content. A large shear-thinning effect indicates that a large fraction of the elastically active cross-links has been severed. Fluorescence measurements on the Py-HASEs confirmed that the smaller the pyrene content of the Py-HASE, the more intermolecular associations it formed, in agreement with the results obtained by rheology. Above the overlap concentration of the polymers, the zero-shear viscosity of the Py-HASE solutions increased steeply with increasing polymer concentration. The onset concentration where viscosity increases matches the onset concentration where intermolecular associations are being formed, as probed by fluorescence. Oscillatory rheological measurements were carried out to determine the terminal relaxation time, Td, and the storage modulus at the infinite time limit, G0, of the Py-HASE network. G0 was found to increase with decreasing pyrene contents, indicating that Py-HASEs with lower pyrene contents exhibited a higher density of elastically active chains. This result is in agreement with the trends obtained by the fluorescence and steady-state rheology measurements. A model is suggested that accounts for the fluorescence and rheology results.
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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".