Absolute Orientation of Ester Side Chains on the PMMA Surface
Bibliographic record
Abstract
Phase-resolved sum-frequency generation spectroscopy has been used to measure the complex, nonlinear susceptibility spectra of the ester methyl groups at the poly(methyl methacrylate)–air interface. The response of the ester methyl symmetric stretch is found to be in phase with that of the aliphatic methyl symmetric stretch in an ordered octadecylsilane monolayer. However, because the local bonding environments of these two methyl groups differ significantly, the signs of the molecular hyperpolarizability tensor elements are not necessarily the same. Therefore, the ester methyl orientation cannot be inferred from the phase measurements alone. To address this ambiguity, the relevant tensor elements were calculated for both types of methyl groups. Results of these calculations, combined with spectroscopic evidence, indicate that the ester methyl groups at the polymer surface are oriented with their hydrogen atoms directed toward the air. This finding may be used to better understand the hydrophobicity and reactivity of the polymer surface.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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".