Nanostructured-Materials

Porous_fibers

  • Description of the effort: This effort seeks to develop encapsulation and controlled release techniques of functional materials inside porous fibers for a broad range of applications including autonomous composites and multifunctional/smart textiles. This work benefits from the high degree of porosity that can be gained via phase separation techniques in polymeric fibers.

porous_fibers

Figure. Left: SEM images of porous PMMA fibers electrospun with different degrees of solvent volatility and humidity. Scale bar: 3 μm. Right: a) Coating thickness vs spray duration. SEM images for different spray coating duration. Scale bar: 3 µm.

 

Figure. Left: Controlled radial release of embedded functional material which is based on diffusion of water molecules across the coating into the fibre, followed by dissolving the encapsulated salt and outward diffusion. Right: Axial release of embedded functional material in response to fibre fracture which is based on the flow of water inside, dissolving the embedded functional material and carrying it out

  • Main findings so far:
    • We have developed a comprehensive map of pore formation via phase separation in order to develop interconnected pore structures in electrospun fibers. Pore interconnection is required to fill the porous fibers and will facilitate the release of the encapsulated functional materials.
    • We have presented a novel sequential processing approach to fabricate highly versatile fibers with broad applicability as the building block of smart textiles,
    • Our results point to the controllability of radial release by adjusting the coating thickness and morphology of the coating at temperatures below Tg of the coating.
    • Axial release of the encapsulated material was demonstrated as a means to release a considerable volume of the filler (as much as 70-90% of the fibre total volume in some sections).
  • Senior personnel involved: Dr. M. Naraghi (Single PI) and Dr. James Boyd
  • References
    • Chen Y., Boyd J., and Naraghi M., “Porous Fibers with Encapsulated Functional Materials and Tunable Release as a Platform to Develop Versatile Multifunctional Textiles”, Journal of Microencapsulation, in press, 2017.