Preparation and Characterization of Polyion-Complexed Langmuir−Blodgett Films Containing an NLO Chromophore
Bibliographic record
Abstract
Polyion complexes formed by monolayers of quaternary ammonium amphiphiles containing the 4-nitro-4'-alkoxy azobenzene chromophore spread at the surface of aqueous solutions of a number of anionic polyelectrolytes were investigated. In general, pi-A isotherms were found to depend on the nature of the polyion present in the subphase, with monolayers of complexes involving polycarboxylates tending to exhibit larger limiting areas than those formed with polysulfonates or polysulfates. Monolayers of the polyion complexes can be transferred to hydrophilic solid substrates to yield Z-type LB films, although some peeling off for more than 10 layers is an impediment. X-ray reflectivity measurements indicate that relatively smooth and uniform films are obtained up to about 10 layers. Average layer thicknesses are, however, significantly smaller than extended molecular lengths, implying that the amphiphiles are strongly inclined from the surface normal. Polarized FT-IR measurements also indicate poor molecular orientation perpendicular to the surface. Preliminary SHG measurements for LB films of two systems, 12Q/CMC-Na and 12Q/PAA, confirm the presence of noncentrosymmetric out-of-plane chromophore ordering. Stable signals are observed for elevated temperatures up to 130 degrees C and for a period of 4 months at room temperature. To the best of our knowledge, this represents the first report of stable SHG in LB films of polyion complexes.
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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) | 0.001 | 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".