Interfacial crosslinking to prepare ultra-thin polydimethylsiloxane thin-film composite membranes
Bibliographic record
Abstract
Thin film composite (TFC) membranes have emerged as pivotal components in diverse industrial applications, including carbon capture, water purification, and gas separation. Among membrane materials, polydimethylsiloxane (PDMS) stands out for its high gas permeability, making it ideal as a selective layer for some industrial separations and as a gutter or protective layer for other membranes. This study focuses on the development of ultra-thin PDMS-based TFC membranes in a process mirroring interfacial polymerization, aiming to achieve defect-free films with enhanced gas permeance and selectivity. By varying acid-chloride-functionalized PDMS and polyethylenimine (PEI) concentrations in the organic and aqueous phases, respectively, and optimizing reaction times, membranes were fabricated and characterized for their morphological, chemical, and performance properties. Results demonstrate that the interfacial crosslinking approach can produce defect-free PDMS films as thin as ∼50 nm, significantly thinner than conventional PDMS TFC membranes produced through coating methods. Gas permeation tests revealed high CO 2 permeance and selectivity (e.g., 3290 ± 340 GPU with a CO 2 /N 2 selectivity of 12 ± 3), showcasing potential for efficient gas separation applications. Furthermore, this technique of using polymers with reactive end groups in interfacial crosslinking to yield ultra-thin rubbery selective layers may prove useful for a variety of different polymer chemistries and membrane applications. • Interfacial polymerization was extended to make ultra-thin (∼50 nm) and defect-free PDMS selective layers. • Acid-chloride-terminated PDMS in the organic phase was crosslinked using polyethyleneimine (PEI) in the aqueous phase. • Maximizing PDMS content, while minimizing PEI content, enhanced CO 2 permeance. • Increased reaction time increased thickness, with decreasing CO 2 permeance and constant CO 2 permeability.
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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) | 0.001 | 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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".