Dependence of methanol permeability on the nature of water and the morphology of graft copolymer proton exchange membranes
Bibliographic record
Abstract
Abstract Novel polymers with controlled microstructures were prepared and studied to further advance the understanding of structure–property relationships of proton conducting membranes. PAN‐g‐macPSSA membranes, which contained poly(styrenesulfonic acid) (PSSA) grafts of defined graft length, are compared with PVDF‐g‐PSSA membranes, prepared by radiation‐grafting, and Nafion® 117. The intrinsic properties of PAN‐g‐macPSSA membranes are insensitive to the macromonomer graft length but are highly dependent on the ion exchange capacities (IEC). Increasing the IEC increases the content of free water absorbed by the membrane. Self‐diffusion coefficients of water in water‐swollen PAN‐g‐macPSSA were found to be similar to that of N117, despite PAN‐g‐macPSSA's higher water content. Of the polymers studied, PAN‐g‐macPSSA exhibited the lowest methanol permeability, which is explained on the basis of it containing a more tortuous ionic network. Methanol permeability decreased with decreasing volume of free water. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2240–2252, 2006
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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 | 0.001 |
| 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".