Electrospun structures with controlled specific surface areas and pores
- Paper number
IAC-06-C2.4.07
- Author
Ms. Vasana Maneeratana, Student, United States
- Coauthor
Dr. Wolfgang Sigmund, University of Florida, United States
- Year
2006
- Abstract
Controlling the pore structure of materials will always be important for a wide variety of applications such as heat transfer, composites, gas permeation, impurities, biological waste, and more. Due to the high surface areas that fibers often offer, we designed a technique with electrospinning to produce novel hollow alumina fibers that serve as the building blocks for our porous structures. Our technique has produced fibers in the micrometer range in room temperature; similar to those from conventional melt spun fibers, but can also produce fibers in the nanometer range. Although electrospinning is a technique that has been given a wide array of attention in the past decade, wherein our technique delivers a new avenue with a one step method to produce hollow fibers, without the need of complicated systems. This reduction in size and hollow quality thus increases the specific surface area available without sacrificing pore architecture and size. The electrospinning process requires a mixture of aluminum sec butoxide and sec butanol connected to a high voltage source. Varying parameters, such as the needle gauge, voltage, and flow rate of our electrospinning system, we have easily altered the diameter of the hollow fibers. After electrospinning, the fibers are collected and heat-treated up to a range of 1100-1500ºC with little organic burnout that may sacrifice structural integrity. The characteristics of the pores, specific surface area, and thermal properties were investigated and compared for various architectures. Furthermore varying the fiber size even allows us to design materials that taper in pore sizes, which thus supports designs for thermal and gas permeation applications. Likewise electrospun fibers often have surfaces with residual charges that can aid in bonding and filtration applications. Lastly controlling the surface area and pore microstructure, allows this technique to be adapted to other material compositions, such as silicates or borosilicates for cryogenic and high temperature foams, oxides for thermal blankets, solid oxide fuel cells, silicon carbides or silicon nitrides for ceramic matrix composites, and more.
- Abstract document
- Manuscript document
IAC-06-C2.4.07.pdf (🔒 authorized access only).
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