Characterization of the stable and metastable poly(ethylene oxide)–urea complexes in electrospun fibers
Bibliographic record
Abstract
Abstract Solution electrospinning was used for the first time to prepare nanofibers of the stable (α) and metastable (β) complexes between poly(ethylene oxide) (PEO) and urea. Both types of fibers were highly crystalline and presented a large level of molecular orientation. Detailed characterization of the ill‐studied β complex was performed using wide angle X‐ray diffraction (WAXD), infrared spectroscopy, and differential scanning calorimetry (DSC). Results reveal that it possesses a 3:2 PEO:urea stoichiometry and suggest that it belongs to the orthorhombic system with a = 1.907 nm, b = 0.862 nm, and c = 0.773 nm. The PEO chains are oriented along the fiber axis and present a conformation significantly affected by strong hydrogen bonding with urea when compared with the pure polymer and the stable complex. A layered structure model is suggested for the metastable complex, in which the urea molecules would be arranged into a ribbon‐like structure intercalated between two PEO layers. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1903–1913, 2008
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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".