Modification of the AMX membrane surface by polyethyleneimine: Effect of ionic strength on the membrane ion exchange selectivity
Bibliographic record
Abstract
Abstract In order to improve the selectivity of the AMX membrane, a polyethyleneimine (PEI) layer was adsorbed on its surface by the immersion of the considered membrane in a solution of PEI. The adsorption process of PEI was studied and the results were well correlated with the Langmuir model and with Lagergren's pseudo‐first‐order kinetic model. Equilibrium ion exchange isotherms of , , and systems, using modified AMX membrane, were established at various ionic strengths from 0.1 to 0.5 mol/L and at constant temperature of 298 K. The results obtained with the modified membrane, in this range of ionic strengths, showed that the affinity order was: at I = 0.1 mol/L and I = 0.2 mol/L and it was for I = 0.3 mol/L and I = 0.5 mol/L. The ion exchange selectivity coefficients , thermodynamic ion exchange equilibrium constants , and the standard free enthalpies of the ion exchange reactions were determined for the three binary systems. These results were compared with those obtained with the unmodified membrane. It was observed that for the modified membrane the ion exchange selectivity towards sulphate ions decreased and increased towards monovalent anions.
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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 | 0.001 |
| 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".