Macroporous Monolithic Methylsilsesquioxanes Prepared by a Two-Step Acid/Acid Processing Method
Bibliographic record
Abstract
The development of monolithic methylsilsesquioxane (MSQ) materials with bicontinuous meso-/macroporous morphologies has proven to be advantageous for the fabrication of chromatographic stationary phases. However, it is currently very difficult to obtain suitable columns over a range of capillary sizes, owing to alterations in morphology in narrow diameter capillaries and material shrinkage in large-bore capillaries. Herein, we describe a new acid/acid two-step sol−gel processing method (A2) for fabricating MSQ bicontinuous monolithic capillary columns with sizes ranging from 20 to 530 μm. The effect of temperature on pore volume and pore size of the related bulk gel was characterized by mercury intrusion porosimetry. It was found that the pore morphologies are stable at 300 °C while pores contract significantly at 400 °C. The evolution of the MSQ chemical structure upon heat treatment was examined by infrared spectroscopy and thermogravimetric analysis. IR spectra demonstrate that both the unstable Si−C bonds (from SiCH 3 groups) and the opening of rings at temperatures of 400 °C are responsible for the densification of gel skeletons and the collapse of macropores. These results indicate that column fabrication should be done without a calcining step to avoid irreversible loss of desirable morphologies and chemical properties.
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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".