Preparation of electrospun polyurethane filter media and their collection mechanisms for ultrafine particles

Figures & data

Figure 1. Schematic diagram of electrospinning equipment.

Figure 2. Experimental setup to measure the collection performance of filter medium.

Figure 3. Viscosity of polyurethane solution at various concentrations.

Figure 4. FE-SEM images and fiber diameter distributions of electrospun filter medium.

Figure 5. Electric currents at various (a) applied voltages and (b) tip-to-collector distances.

Table 1. Physical properties of test filters

	Electrospun filter	Microsized filter
Fiber density, ρf (g/cm^3)	1.2	0.92
Average fiber diameter, df (nm)	180	2878
Variance of fiber diameter, σ (—)	0.062	0.355
Filter thickness, L (mm)	0.033	0.161
Packing density of a filter, α (—)	0.023	0.226
Pressure drop at U = 3 cm/sec, ΔP^r (Pa)	172	147

Figure 6. Particle penetrations of an electrospun filter at filtration velocity of 0.5 cm/sec.

Figure 7. Particle penetrations of an ethanol-treated filter at filtration velocity of 0.5 cm/sec.

Figure 8. Single fiber collection efficiencies of ethanol-treated filter and microsized filter as a function of Peclet number.

Figure 9. FE-SEM image of particles loaded filter.

Figure 10. Filter quality factor of ethanol-treated filter and electrospun filter.