Preferential Adsorption and Co-nonsolvency of Thermoresponsive Polymers in Mixed Solvents of Water/Methanol
Bibliographic record
Abstract
If two good solvents become poor for a polymer when mixed, the solvent pair is called a co-nonsolvent pair for the polymer. The sharp depression of the LCST by the co-nonsolvency in solutions of poly( N -isopropylacrylamide) in the mixed solvent of water and methanol is shown to be caused by the competitive hydrogen bonding of water and methanol molecules onto the polymer chains. On the basis of a new statistical-mechanical model for competitive hydrogen bonds, the degree of hydration θ (w) and of methanol binding θ (m), excess degree Δθ E of solvent binding, preferential adsorption coefficients Γ, LCST spinodal lines, and cloud-point depression Δ T cl are theoretically calculated and compared with the experimental results. The optimal composition x m ( M ) of methanol at which LCST takes the minimum value is studied as a function of the polymer molecular weight M. In the high molecular weight limit, it takes x m ≃ 0.35. The solution recovers a uniform state in the region of higher methanol composition. Such a peculiar phase separation is caused by the dehydration of the polymer chains by the mixed methanol molecules in a cooperative way.
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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) | 0.000 | 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 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".