Synthesis and Properties of Charge-Shifting Polycations: Poly[3-aminopropylmethacrylamide-<i>co</i>-2-(dimethylamino)ethyl acrylate]
Bibliographic record
Abstract
Charge-shifting copolymers of N -(3-aminopropyl)methacrylamide (APM) and 2-(dimethylamino)ethyl acrylate (DMAEA) were prepared and investigated as potential replacements for conventional polycations like poly( l -lysine) (PLL) in biomaterial applications. 1 H NMR was used to determine the reactivity ratios of APM and DMAEA to be 0.89 and 0.37, respectively, at pH 3–4 where both monomers were protonated and DMAEA was hydrolytically stable. Conventional free radical and reversible addition–fragmentation chain transfer (RAFT) copolymerization were used to prepare a series of P(APM- co -DMAEA) (PAD) copolymers with different MWs and compositions. Charge shifting from cationic toward neutral and anionic net charges by hydrolysis of DMAEA units was determined by 1 H NMR to depend on both composition and pH (pH 9 > 7 > 5). PAD copolymers bound strongly to anionic polymer particles and calcium alginate beads. For calcium alginate, the amount of PAD bound and the shell thickness depended on copolymer composition and MW. The PAD coating underwent hydrolysis and was released from the anionic surfaces as shown by microscopy and electrophoretic mobility measurements. PAD coatings that were cross-linked with tetrakis(hydroxymethyl)phosphonium chloride (THPC) remained on the capsule surface after hydrolysis to form amphiphilic or anionic cross-linked surfaces.
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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".