Surfactant-Free Polymerization Forming Switchable Latexes That Can Be Aggregated and Redispersed by CO<sub>2</sub> Removal and Then Readdition
Bibliographic record
Abstract
Polystyrene latexes prepared using the bicarbonate salt of initiator 2,2′-azobis[2-(2-imidazolin-2-yl)propane] via surfactant-free emulsion polymerization can be aggregated using only argon and gentle heat and redispersed using carbon dioxide and sonication. The bicarbonate and hydrochloride salts of the initiator have similar thermal decomposition behavior, but only the bicarbonate salt of 2,2′-azobis[2-(2-imidazolin-2-yl)propane] can be switchable between ionic and nonionic forms by addition and removal of CO 2 . Measurements of particle size and zeta potential were used to study the aggregation and redispersion of the latexes. The latex is aggregated by heating and bubbling with argon to remove CO 2 and convert the active cyclic amidinium groups to their neutral form. When treated with sonication and bubbling with CO 2, the aggregated polystyrene latex can be redispersed successfully, as evidenced by restoration of the original latex particle size and zeta potential from the large aggregated polymer particles. This is the simplest method to date to prepare a redispersible latex stabilized by CO 2 .
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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 | 0.001 |
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".