Porous Membranes of Polysulfone-<i>g</i><i>raft</i>-poly(<i>tert</i>-butyl acrylate) and Polysulfone-<i>g</i><i>raft</i>-poly(acrylic acid): Morphology, pH-Gated Water Flow, Size Selectivity, and Ion Selectivity
Bibliographic record
Abstract
Membranes were prepared from two samples of polysulfone- graft -poly( tert -butyl acrylate), PSf- g -P t BA, by immersion into water of solution films of the polymers first solvated in 1-methyl-2-pyrrolidinone (MP) and propionic acid (PA). Polysulfone- graft -poly(acrylic acid), PSf- g -PAA, membranes were obtained after soaking the PSf- g -P t BA membranes in trifluoroacetic and formic acid to hydrolyze P t BA. Both PSf- g -P t BA and PSf- g -PAA membranes had high water permeability. An electron microscopic study revealed that the membranes were porous and asymmetric. In the skin layer, the polymer formed a nodular phase consisting of fused polymer lumps surrounded by void channels. The PAA chains and presumably also the P t BA chains were concentrated at the lump/lump or lump/void interfaces. At a constant pressure, the water flux across PSf- g -PAA membranes decreased with increasing solution pH probably due to the extension of the PAA chains into the channels at high pH. The PSf- g -PAA membranes also showed permselectivity toward anions of lower valence and may be used to separate NaCl from Na 2 SO 4, for example. A permeation test using poly(ethylene glycol) samples of different molar masses showed that membranes of a PSf- g -PAA sample had a size of ∼2 nm at constrictions of the nanochannels.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| 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".