Structural Property Effect of Nanoparticle Agglomerates on Particle Penetration through Fibrous Filter

Figures & data

FIG. 1 Schematic of NP agglomerates penetration test system.

FIG. 2 SEM images of NP agglomerates (1st row: 50 nm, 2nd row: 200 nm) as a function of sintering temperature (1st column: room temperature, 2nd column: 200°C, 3rd column: 600°C).

FIG. 3 NP agglomerate penetration as a function of sintering furnace temperature (test filter: HE 1073, face velocity: 5.3 cm/s, 1st furnace temperature: 1,150°C).

FIG. 4 DMA-APM system for NP agglomerates mobility diameter and mass measurement.

FIG. 5 Mass distribution of 199 nm NP agglomerates measured by DMA-APM system (1st furnace temperature: 1,150°C, 2nd furnace temperature: ambient).

TABLE 1 Mean and the standard deviation for the mass, length, and width

Temp.	Dm (nm)	Mass (fg)	L (nm)	W (nm)	L/W
R.T.	50	—	91.11 ± 25.82	53.35 ± 14.38	1.79 ± 0.61
	100	1.07 ± 0.03	203.13 ± 59.04	123.38 ± 35.18	1.71 ± 0.56
	150	2.56 ± 0.12
	200	4.88 ± 0.09	500.24 ± 81.39	308.91 ± 58.18	1.69 ± 0.50
	250	7.36 ± 0.24
	300	10.39 ± 0.28
100°C	50	0.29 ± 0.02
	80	0.77 ± 0.03
	100	1.22 ± 0.03
	150	2.82 ± 0.08
	200	5.09 ± 0.14
	300	11.68 ± 0.33
200°C	50	0.47 ± 0.04	73.17 ± 17.60	42.35 ± 7.58	1.76 ± 0.43
	80	1.43 ± 0.04	124.04 ± 25.76	71.09 ± 16.70	1.84 ± 0.62
	100	2.34 ± 0.07	156.17 ± 30.00	88.93 ± 16.51	1.80 ± 0.43
	150	5.93 ± 0.14
	200	10.59 ± 0.37
600°C	50	0.57 ± 0.02
	80	2.31 ± 0.22
	100	4.39 ± 0.55
	120	4.88 ± 0.71
	150	6.28 ± 0.31

FIG. 6 NP agglomerate mass versus mobility diameter for various sintering temperatures (1st furnace temperature: 1,150°C, residence time in agglomeration chamber: 2 min).

FIG. 7 TEM images of NP agglomerates as a function of sintering temperature (a) 50 nm at R.T., (b) 100 nm at R.T., (c) 50 nm at 200°C, (d) 100 nm at 200°C, (e) 50 nm at 600°C, and (f) 100 nm at 600°C.

FIG. 8 Primary particle size distribution (1st furnace temperature: 1,150°C, 2nd furnace temperature: ambient, residence time in agglomeration chamber: 2 min).

FIG. 9 Maximum length distributions of NP agglomerates for various mobility diameters (1st furnace temperature: 1,150°C, 2nd furnace temperature: ambient, residence time in agglomeration chamber: 2 min).

FIG. 10 Maximum length of NP agglomerates as a function of sintering temperature.

FIG. 11 Aspect ratio analysis of NP agglomerate (1st furnace temperature: 1,150°C, 2nd furnace temperature: ambient, mean value: 1.65).

FIG. 12 Dynamic shape factor of agglomerates with different sintering temperatures.

FIG. 13 Modeling results of NP agglomerates penetration.

TABLE 2 Efficiency factors for the deposition for each mechanism

	Room temperature
Mobility diameter (nm)	E diff	E imp	E int	E DR	E Σ
30	0.31124	0.00002	0.00066	0.02838	0.34030
50	0.16321	0.00008	0.00237	0.02694	0.19259
80	0.09211	0.00026	0.00761	0.02609	0.12608
100	0.07095	0.00047	0.01317	0.02591	0.11051
150	0.04517	0.00137	0.03522	0.02602	0.10778
200	0.03348	0.00285	0.06976	0.02650	0.13259
300	0.02264	0.00675	0.17784	0.02785	0.23507
	200°C
	E diff	E imp	E int	E DR	E Σ
30	0.31124	0.00003	0.00058	0.02726	0.33911
50	0.16321	0.00011	0.00175	0.02433	0.18941
80	0.09211	0.00035	0.00479	0.02228	0.11954
100	0.07095	0.00062	0.00770	0.02154	0.10081
150	0.04517	0.00176	0.01807	0.02060	0.08560
200	0.03348	0.00371	0.03283	0.02027	0.09029
300	0.02264	0.01047	0.07501	0.02029	0.12841
	600°C
	E diff	E imp	E int	E DR	E Σ
30	0.31124	0.00002	0.00029	0.02166	0.33320
50	0.16321	0.00007	0.00081	0.01876	0.18286
80	0.09211	0.00031	0.00205	0.01671	0.11119
100	0.07095	0.00063	0.00318	0.01594	0.09071
150	0.04517	0.00232	0.00704	0.01489	0.06942
200	0.03348	0.00596	0.01231	0.01441	0.06616
300	0.02264	0.02307	0.02680	0.01408	0.08660

FIG. 14 NP agglomerate penetration as a function of particle mass.