AWWA MTC64555

Electrospinning creates sub-micron to nano-scale fibers through an electrically chargedjet of polymer solution/melt. Through this process, non-woven membranes for separationtechnology can be developed. These electrospun nanofibrous membranes (ENMs)possess desirable attributes such as high porosity (>80%), pore sizes ranging from tens ofnanometer to several micrometers, interconnected open pore structure and large surfacearea per unit volume, highly attractive as barrier materials for separation technology aswell as biotechnology. This paper explores the viability of developing a fibrousmembrane via electrospun nanofibrous web for separation technology and demonstratesits applicability in particulate removal. Polysulfone nanofibers were electrospun intomembranes and characterized to relate its structural properties to membrane propertiesand performance. Membranes of different fiber morphologies and diameter wereelectrospun by varying the polymer concentration from 15, 18 and 20 %wt/vol. Beadednanofibers (280 nm) were obtained from 15% solution and nanofibers of 350nm and500nm from 18% and 20% solution respectively. Presence of beaded fibers and thethickness of the ENMs were observed to have a significant influence on the pore-sizedistribution, mean flow pore-size and bubble point. The presence of beads, if numerous,will lead to smaller pore-sizes as well as porosity. Likewise, as the thickness of theENM increased, the pore-size also reduced but this is due to more layers of nanofibersdeposited which hinders the flow path. It was shown that theENMs can be successfully employed as filters for the removal of micro-particles abovetheir bubble point. When the micro-particles are larger than the pores within the ENM,the membrane acts as a screen filter and no fouling was observed. The ENM was mostseverely and irreversibly fouled when separating 2 and 1 um particles. However, to fullyunderstand this phenomenon, more tests are required. When sub-micron particles wereseparated, they tend to get attracted to the surface of the nanofibers and thus the ENMacts as a depth filter. The above findings highlight the potential of ENMs as barriermaterials for separation technology. There are immense potential applications both inbiotechnology as well as water treatment. These membranes can be used as pre-filtersprior to ultrafiltration or nanofiltration to minimize the possibility of fouling andcontamination from micro-organisms or micro-particles. Includes 21 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

03/01/2007

Number of Pages:

16

File Size:

1 file , 5.3 MB