Application of Different Types of Polyaryl-Blend-Membranes in DMFC
Bibliographic record
Abstract
In this comparative study, the preparation and characterization as well as the direct methanol fuel cell (DMFC) application of ionically, covalently, and covalent-ionically cross-linked polyaryl-blend membranes is described. The proton-conductive component of the blend membranes consists of sulfonated poly(etherketones) sPEK. Ionic cross-linked membranes were formed by mixing sPEK and two different basic PSU polymers, and covalently cross-linked membranes were prepared by mixing of sPEK with sulfinated PSU, where the covalent cross-links were formed by sulfinate-alkylation with,! -diiodobutane. Covalently and ionically cross-linked blend membranes were formed by mixing sPEK with sulfinated PSU and a basic PSU polymer, where the cross-linking took place by tertiary basic N and sulfinate alkylation with,! -diiodobutane. The polyaryl-blend membranes showed thermal stabilities between 250 and 270 C. The covalently and the ionically cross-linked membranes show a homogeneous blend morphology, while the covalent-ionivally cross-linked membrane was microphase-separated. The differently cross-linked membranes showed similar proton-conductivity and ion-exchange capacity but different swelling behavior at T = 90 C: the swelling degree (SW) of the covalently cross-linked membrane was only 50% of the SW of the two other membranes. The DMFC performance of the differently cross-linked membranes was similar and comparable with that of Nafion 105, although the meOH permeability of the polyaryl-blend membranes was a factor 2 to 2.4 lower than that of Nafion 105. A better performance of the polyaryl-blend membranes was most probably prevented by a bad connection between recast Nafion-containing electrodes and the membranes.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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) | 0.000 | 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 teacher head, 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".