Fabrication of polydiacetylene particles using a solvent injection method

Polydiacetylenes (PDAs) are a class of conjugated polymers with unique optical properties that have practical applications in a diverse range of fields. PDA vesicular particles are typically constructed using a thin film hydration method which suffers from a lack of scalability and requires techniques such as sonication and extrusion to control particle size. These procedures are energy-intensive and limit the application of the thin film hydration method to small-scale vesicle production. We present the first application of the solvent injection method to synthesize PDA vesicles as an alternative method of high throughput production. PDA vesicles are constructed from a range of DA monomers that vary in their total carbon chain length and were analyzed using transmission electron microscopy, dynamic light scattering, and zeta potential measurements. Using the solvent injection method, we found longer alkyl chain length monomers produce smaller particles that are more easily photopolymerized. The function of the PDA is verified for the detection of ammonia gas. 8,10-Henicosadiynoic acid is nominated as the optimum PDA system as it has a moderate chain length which results in both optimum morphology and ammonia detection sensitivity. The results from this study suggest that the solvent injection method is a viable alternative to the thin film hydration method for large scale PDA particle production.