Novel Copolymers Based on Methoxythiophene-Flanked Diketopyrrolopyrrole for Wearable Resistive Sensors
Bibliographic record
Abstract
The exposure that firefighters experience due to their occupation has recently been identified by the World Health Organization as a Group 1 carcinogen. One factor is colorless, odorless, toxic gases in “warm zones” near enough to fires where awareness and protection are lowered but the actual risks are still high. The current gas sensors available are based on metal oxides, and are bulky, inflexible, and costly to produce. By contrast, gas sensors based on conjugated polymers promise to be lightweight and flexible enough to weave directly into clothing and could be manufactured using low cost roll-to-roll printing. However, they require improvements in stability. \n \nThis work first establishes a baseline of stability for previously reported conjugated polymers. Common p-type dopant molecules are used to dope diketopyrrolopyrrole (DPP) copolymers, which are known for their stability. It was found that the longest the sensors could last was ~10 days. \n \nBelieving that the stability could be improved through increasing the energy level of the polymer’s Highest Occupied Molecular Orbital (HOMO), this thesis extends a recent report of a novel DPP-flanking group, methoxythiophene. The potential of methoxythiophene-flanking groups as a method to raise DPP polymer HOMO energy has several advantages. They are sterically small (only extending the length of the thiophene molecule by < 2.5 Å) and by using the flanking group to raise the HOMO, both the choice of solubilizing side chain and choice of comonomer remain free. A solubilizing side chain with thermally/chemically removable groups could therefore be used. The removal process could introduce stable pores, enhancing gas transport in and out of the polymer film. Likewise, a comonomer could be selected for its interaction with a target gas. \n \nThree novel conjugated DPP-based copolymers were then synthesized, using methoxythiophene as a flanking group to the DPP unit. Two were produced through Stille coupling and one was produced through the more environmentally friendly Direct Arylation Polymerization (DArP). \n \nAs hypothesized, these copolymers show high HOMO levels, which are anticipated to grant them high stability once doped with common p-dopants. One, C8-EDOT shows conductivity stable in air over 2 months (~1%/day decrease in current) even without exogenous dopant, having been doped by trace HCl in chloroform used to coat films. The three polymers also show ultralow bandgaps, which could make them useful in Near Infrared detection or Organic Photovoltaic applications.
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 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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".