Swelling and Dissolution Transitions of DNA- and “Bis”-Cross-Linked Polyacrylamide
Bibliographic record
Abstract
We examine the swelling and dissolution of hydrogels cross-linked by a combination of physical and chemical junctions, focusing on the technologically important DNA- and “bis”-cross-linked polyacrylamide architecture. A theoretical model to account for the binding energy of physical cross-links and their coupling to the elastic free energy identifies network characteristics that control access to swollen and dissolved states. The model provides a theoretical basis for interpreting nonswelling, swelling, and dissolution states reported in the literature, accomplished with specific polymer and cross-linking concentrations. Here, we extend the experimental parameter space, showing that similar cross-linking architectures, but with lower polymer and cross-linking concentrations, spontaneously access highly swollen states, not previously reported in the literature. This is achieved by releasing network strands into the bath following the irreversible dissociation of DNA cross-links by a “ratcheting” mechanism. The free-energy barrier to access highly swollen (for dual-cross-linked networks) and dissolved states (for DNA-only cross-linked networks) is estimated to be ∼0.1 k B T ϕ 0 V 0 / v, where v is the volume of a solvent molecule and ϕ 0 V 0 is the volume of the polymer. When including Donnan/electrostatic effects on swelling (which are secondary to the binding/dissociation effects that are central to this study), we find that DNA has an effective charge of ≈−0.74 e per base/phosphate (in 150 mmol L –1 swelling buffer), higher than the ≈−0.24 e for Manning counterion condensation in a salt-free buffer.
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 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) | 0.000 | 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".