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314 PAO-KUAN WANGRROIUS OF PRRTICLE IMICRONSIFIG. 14. Comparison between the collection kernels of aerosol particles captured by spheres of radiusa = 30 pm with (-) and without (- - -) ventilation effects. Curves (l)-(5) are for cases withoutventilation effects and E. = 100, 500, 1000, 2000, and 3000 V/cm, respectively. Curves (6)-( 10) are forcases with ventilation effects and E0 = 100, 500, 1000, 2000, and 3000 V/cm.,.,(-g-,.,(-g)= lim n,Leo Q-0q--‘o 930 1 - exp= lim n,e-0PO1Da---- BQq 1Da 2!(neglect higher order terms)1451Journal of C&id and Interfac Science, Vol. 94, No. 2, August 1983
COLLECTION OF AEROSOL PARTICLES 31510 .OOl a.111 2. I ,‘,‘,,,,,,““, 5. .Ol 2. 1,1,,,,,,,,,, 5. .I I,, 2. ,,,,, 5. ,,,, ‘ioRROIUS OF PRRTICLE [MICRONSIFIG. 15. Same as Fig. 14 except for a = 100 Grn.Equation [45] is the well-known particledistribution around a sphere due to pureBrownian motions (see, e.g. (8)).(iii) Very strong external electric field.When the external field is so strong as topredominate the whole process, the particledistribution is solely determined by the externalfield. The total mass flux toward thesphere is the convective current due to theexternal field. This can be easily obtained bytaking Eoa2 S @I in Eq. [35]. Since &- ?r/2 in this case, we haveK x 3?rEoa2Bq 1461since the first term is a negative number andshould be set to zero. Equation [46] is thewell-known convective current due to a uniformexternal field E0 (see, e.g. (1 S), for thecase of ion transport toward a spherical dropdue to Eo).CONCLUSIONSIn the above discussions we have shownthat the distribution of aerosol particles bya stationary, conducting sphere in the presenceof an external electric field can be describedby the convective diffusion Eq. [13]with solution Eqs. [25] and [3 11. The particleflux is given by Eqs. [34]-[38]. We have alsoproved that in the limiting cases (i) E,, = 0,(ii) pure Brownian diffusion, and (iii) verystrong E,, the above solutions can be reducedto proper solutions for these cases.Although the present paper deals exclusivelywith the electrostatic forces, the formulationis quite general and is valid for anyconservative force fields whose potentials satisfythe Laplace equation. Thus one can easilyadd forces such as thermo- and diffusiophoreticforces.We want to stress, however, that we havenot included the hydrodynamic forces whichJournal ofCo/loid and Inlerjace Scrence, Vol. 94, No. 2, August 1983
Page 1 and 2: Collection of Aerosol Particles by
Page 4 and 5: 304 PAO-KUAN WANGwherezero everywhe
Page 6 and 7: 306 PAO-KUAN WANGdnBi% ‘33s I=a &
Page 8 and 9: 308 PAO-KUAN WANG1o .OOl 2. 5. .Ol-
Page 10 and 11: 1o .OOl 2. 6. .Ol 2. 5. .l 2. 5.I -
Page 12 and 13: lo-‘-11 o-6F10-G3-l-& ,*,,2., , ,
Page 16 and 17: 316 PAO-KUAN WANG- 10-i \1o-6 I I I
Page 18: 318 PAO-KUAN WANGACKNOWLEDGMENTThe

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