<sup>13</sup>C Solid-State NMR of the Mobile Phase of Poly(vinylidene fluoride)
Bibliographic record
Abstract
The solid-state 13 C spectra of poly(vinylidene fluoride) (PVDF) acquired by direct polarization (DP) with and without simultaneous 19 F and 1 H decoupling, under moderate sample spinning conditions, are compared to the spectra obtained using direct polarization followed by a short Hahn echo. We show that by using an appropriate combination of saturation and dephasing conditions high-resolution solid-state 13 C NMR spectra of the amorphous domain can be obtained. These spectra allow for a complete assignment of the solid-state 13 C NMR spectra of the amorphous phase of PVDF, and we propose a simple methodology to obtain high-resolution solid-state 13 C NMR spectra of high molecular weight polymers. Furthermore, these spectra lead to the conclusion that differential line broadening is occurring in the multiplet structure of the signals present in the coupled spectra. This can be attributed to relaxation interference effects and further reduces the line width in the coupled spectra, allowing for the dramatically improved resolution. In addition, this explains the loss of resolution when decoupling is applied during the acquisition of the solid-state 13 C spectra of PVDF.
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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".