Nanofiber is a broad phrase generally referring to a fiber with a diameter less than 1 micron. While glass fibers have existed in the sub-micron range for some time and polymeric meltblown fibers are just beginning to break the micron barrier, 0.25 micron diameter electrospun nanofibers have been manufactured and used commercially for air filtration applications for more than twenty years. Several value-added nonwoven applications, including filtration, barrier fabrics, wipes, personal care, medical and pharmaceutical applications may benefit from the interesting technical properties of commercially available nanofibers and nanofiber webs. This paper will discuss the electrospinning process for making nanofibers and nonwoven nanofiber webs from synthetic fiber-forming polymers. The resulting physical characteristics of the nanofiber webs will be discussed. In order to provide a useful context for the nonwovens industry, nanofiber webs will be compared to both melt-blown and spunbond nonwovens. The description and comparison of the properties should provide product designers in the nonwovens industry with the tools to generate product and applications ideas about new uses for nanofibers.

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It has been well documented that DUV lithographic processes are sensitive to airborne contamination such as ammonia and n-methyl-2-pyrrolidone (NMP). Chemical filtration technologies have aided in minimizing the problems associated with these contaminants in the photolithographic process. As the demand for smaller features increases, so will the need to operate within even cleaner environments than are available today. One such area where airborne contamination has proven to be of significant concern, is within the lensing system of the tool. With decreasing feature size, the lithographic process has proven to be more sensitive to contamination of the lens itself, and within the environment surrounding the lens.Condensation on the lens (hazing) and the presence of contamination between the lens and substrate can result in poor optical transmission. To minimize these problems, a purge gas is typically employed. Even though high purity gases are used, contamination within the gas still is an issue. This work describes our efforts directed at understanding the purge gas and lens environments. In addition, we will address our efforts that have focused on the development of chemical filters that provide environments for optimized optical transmission in lithographic applications.

It is well established that sub-micron ambient aerosol contamination of the intake air can produce fouling of the gas turbine compressor and result in a reduction of power output. Application of electrospun nanofibers of 0.25 micron diameter to a conventional filter media substrate has been demonstrated to improve the efficiency of gas turbine intake filters to remove sub-micron contaminate. The benefits of nanofiber filtration have been proven through use in gas turbine intake air filtration and other industrial and defense filtration applications for over twenty years. Recent advancements in electrospun nanofiber media technology have increased the filtering efficiency of gas turbine intake filters, with minimal differences in filter element pressure loss. These advances have also improved the durability of nanofibers in high temperature and high humidity applications. This paper discusses the laboratory testing that demonstrates these performance and durability improvements. A comparative field test program demonstrates the capability of nanofiber filtration to significantly reduce the fouling of gas turbine compressors.