Electrospinning creates sub-micron to nano-scale fibers through an electrically charged
jet of polymer solution/melt. Through this process, non-woven membranes for separation
technology can be developed. These electrospun nanofibrous membranes (ENMs)
possess desirable attributes such as high porosity (>80%), pore sizes ranging from tens of
nanometer to several micrometers, interconnected open pore structure and large surface
area per unit volume, highly attractive as barrier materials for separation technology as
well as biotechnology. This paper explores the viability of developing a fibrous
membrane via electrospun nanofibrous web for separation technology and demonstrates
its applicability in particulate removal. Polysulfone nanofibers were electrospun into
membranes and characterized to relate its structural properties to membrane properties
and performance. Membranes of different fiber morphologies and diameter were
electrospun by varying the polymer concentration from 15, 18 and 20 %wt/vol. Beaded
nanofibers (280 nm) were obtained from 15% solution and nanofibers of 350nm and
500nm from 18% and 20% solution respectively. Presence of beaded fibers and the
thickness of the ENMs were observed to have a significant influence on the pore-size
distribution, 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 the
ENM increased, the pore-size also reduced but this is due to more layers of nanofibers
deposited which hinders the flow path. It was shown that the
ENMs can be successfully employed as filters for the removal of micro-particles above
their 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 most
severely and irreversibly fouled when separating 2 and 1 um particles. However, to fully
understand this phenomenon, more tests are required. When sub-micron particles were
separated, they tend to get attracted to the surface of the nanofibers and thus the ENM
acts as a depth filter. The above findings highlight the potential of ENMs as barrier
materials for separation technology. There are immense potential applications both in
biotechnology as well as water treatment. These membranes can be used as pre-filters
prior to ultrafiltration or nanofiltration to minimize the possibility of fouling and
contamination from micro-organisms or micro-particles. Includes 21 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 5.3 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 16 |
| Published : | 03/01/2007 |
