Silver-loading in uncrosslinked hydrogen-bonded LBL films: structure change and improved stability
Bibliographic record
Abstract
As nanoreactor for the synthesis of metal nanoparticles, hydrogen-bonded layer-by-layer assembled (LBL) films may be a better choice than the electrostatic ones, because more carboxylic acid groups are available for metal ion binding. However, these films should be crosslinked before metal ion loading because of their instability (Chem. Mater., 2005, 17, 1099–1105). Here we report that the uncrosslinked hydrogen-bonded poly(vinyl pyrrolidone)/poly(acrylic acid) (PVPON/PAA) LBL films remain stable during Ag+ loading. FTIR and XPS studies indicate that Ag+ binds with PVPONvia coordination interaction, while it simultaneously binds with PAAvia electrostatic interaction. Therefore the films do not disintegrate upon the disruption of hydrogen bonds between PVPON and PAA. After Ag+ loading, the erosion rate of the film in water decreases, indicating that the long-term stability of the film is actually improved. The loaded Ag+ can be easily unloaded by immersing the film in acidic solutions. The loading and unloading of Ag+ are reversible and can be repeated many times. Silver nanoparticles were synthesized in situ by UV irradiation. The nanoparticles are spherical in shape and present a surface plasmon absorption peak at 434 nm.
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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 | 0.001 |
| 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".