Investigating the Water in Hydrated sPEEK Membranes Using Multiple Quantum Filtered <sup>2</sup>H NMR Spectroscopy
Bibliographic record
Abstract
Double and zero quantum filtered (2)H NMR spectroscopy is used to study the structure and dynamics of D(2)O in sulfonated poly(ether ether ketone) membranes as a function of membrane hydration. Both residual quadrupolar coupling constants and T(2) relaxation values are obtained as a function of hydration. The residual couplings vary from 160 Hz at low hydration to 30 Hz at high hydration. The T(2) relaxation times range from 3 to 14 ms, with the high hydration values having longer T(2). Results from this study are compared to results obtained for Nafion membranes, revealing similarities and differences in the water environments of the two membranes that result from the structure of the polymers and can be related to properties such as water diffusion.
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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 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".