Photoinduced Birefringence and Surface Relief Gratings in Polyurethane Elastomers with Azobenzene Chromophore in the Hard Segment
Bibliographic record
Abstract
A series of polyurethane elastomers containing aromatic azobenzene chromophore in the hard segment was synthesized by a one-step method. AFM surface study showed that particles on the order of 100 nm to several micrometers appeared after annealing the polymer films. Birefringence was induced in these polymer elastomers. The stability of the photoinduced birefringence could be improved significantly by annealing the polymer films. This also induced microphase separation. The effects of azo contents and molecular weight of soft segments were investigated. Dynamic study shows that photoinducing rate decreased while relaxation rate increased after annealing. Surface relief gratings could be induced only on the pure polyurethane and the elastomer containing 75% bis(azo)−diol. Only a reversible volume hologram was observed for the other elastomers.
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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".