中文摘要

奈米微粒因為粒徑很小而可能顯現出與巨觀材料性質不同的效應。在大氣中因為天然及人為因素亦產生相當多的奈米微粒，成為大氣氣膠中重要成分。本研究以電噴霧製備奈米微粒並以流動型雲霧室來探討帶電或中性奈米(10nm~15nm)微粒所引起之非均勻相核凝機構。
我們利用電噴霧系統可產生小於10nm之高濃度SiO2微粒。在探討電噴霧特性方面，結果顯示微粒之最高濃度及最高濃度粒徑隨溶液流速及溶液濃度增加而增加，而隨導電度增加而減少。其他如溶劑之表面張力、毛細管內徑及載流氣體之流速亦是影響微粒分佈的重要參數。
實驗結果顯示，臨界過飽和度隨微粒粒徑減小而增加，定性上與理論預測相符合。而在定量上，與過去研究比較，不帶電微粒之臨界過飽和度之實驗值隨著粒徑減小有漸漸大於理論值的趨勢。在帶電微粒部分，結果顯示不電帶微粒之臨界過飽和度大於帶單一電荷微粒之臨界過飽和度。而帶正電荷微粒與帶負電荷微粒在臨界過飽和度的比較上亦有些許差距。

ABSTRACT

Nanoparticles may have a property different from the bulk due to such a small size. Recently, the subjects concerning their production, properties and applications have received extensively attention and been intensively investigated. On the other hand, nanoparticles are generated due to natural and anthropogenic activities, and become an important component of the atmospheric aerosols. A systematic study on the heterogeneous nucleation of vapor on various charged nanoparticles of 10nm to 15nm is performed employing an electrospraying device and a flow cloud chamber (FCC).
An electrospray system has been developed and succeeded in producing SiO2 nanoparticles of less than 10 nm. The peak concentration and diameter increases with liquid flow rate and concentration, but decreases with liquid conductivity. There exist an optimum gas flow rate to achieve a maximum peak concentration.

The experimental size dependence of Scr is in a reasonable agreement with the prediction of the classic nucleation theory. An obvious charged effect on Scr is observed, and the effect is much stronger than the prediction. Water vapor is more readily to condense on negative charge particles.

參考文獻

1. A.C.Zettlemoyer,”NUCLEATION”,Chap.4,p.151,(Marcel Dekker,Inc.)
2. N.H.Fletcher,“The Physics of Rainclouds”,1st Ed.,( Cambridge University
Press), p.390 (1969).
3. H.R. Pruppacher and J.D. Klett, “Microphysics of Clouds and
Precipitation”, (Reidel, Holland), p.714 (1980).
4. Chin-Cheng Chen and Chun-Ju Tao,J.Chem. Phys.112,15(2000) .
5. W. C. Hinds, “Aerosol Techmology”, (Wiley, New York), (1982).
6. M. Danek, K. F. Jensen, C. B. Murray, M. G. Bawendi ,J. Chem. Mater. 8,
173. (1996)
7. C.H.Chen, M. H. J. Emond, E. M. Kelder, B. Meester and J. Schoonman, J.
Aerosol Sci. 30, 7, 959(1999).
8. Zeleny, Z. Proc. Camb. Phil. Soc. 18, 71(1915).
9. Stanley L. Kaufman, J. Aerosol Sci. 29, 5/6 ,537,(1998).
10. K.Tang and A. Gomez , J. Aerosol Sci. 25, 6 ,1237,(1994).
11. Stanley L. Kaufman, Analytical Chemistry News & Features.4, 6, 386A.
12. M. Cloupeau and B. Prunet-Foch,Journal of Electrostatics,22,135
(1989).
13. Da-Ren Chen,*David Y. H. Pui* and Stanley L. Kaufman, J.Aerosol Sci,26,6.963
(1995).
14. Volmer, M., and Weber, A., Z. Physik. Chem. (Leipzig) 119, 227
(1926).
15. Fletcher, N. H, J. Chem. Phys. 29, 572-576 (1958).
16. Lamer, V. K. and Gruen ,R., Trans. Faraday Soc. 48, 410 (1952).
17. Twomey, S., J. Chem. Phys. 30, 941 (1959).
18. Koutsky, J. A., Walton, A. G., and Baer, E., Surface Sci. 3,165 (1965).
19. Jameson, G. J., and Del Cerro, M. C., J. Chem. Soc. Faraday Trans. I 72,
883 (1976).
20. Saville, G., J. Chem. Soc. Faraday Trans. II 73, 1122 (1977).
21. White, L. R., J. Chem. Soc. Faraday Trans. I 73, 390 (1977).
22. Juisto, J. E., and Kocmond, W. C., J. Rech. Atmos. 3, 19 (1968).
23. Liu, B. Y. H., Pui, D.Y.H., Mckenzie, R. L., Agarwal, J. K., Pohl, F. G.,
Preining, O., Reischl, G., Szymansky, W., and Wagner, P. E., Aerosol Sci.
Technol. 3, 107(1984).
24. Porstendorfer, J., Scheibel, H. G., Pohl, F. G., Preining , O., Reischl,
G., and Wagner, P. E., Aerosol Sci. Technol., 4, 65(1985).
25. Lazaridis, M., J. Colloid Interface Sci. 155, 38 6(1993).
26. 郭明升,”水蒸氣在不溶性無機次微米微粒上之非均勻相核凝現象”,碩士論文，國立成
功大學化工系，(1995).
27. 蔡宜哲,”水蒸氣在不溶性次微米微粒上之非均勻相核凝現象” ,碩士論文，國立成功
大學化工系，(1996).
28. 黃崇銓,”正丁醇蒸汽在不溶性無機次微米微粒上之非均勻相核凝現象”,碩士論文，國
立成功大學化工系，(1996).
29. 許豪仁,”正丁醇蒸汽在味精與乳糖次微米微粒上之非均勻相核凝現象”，碩士論文，
國立成功大學化工系，(1997).
30. 陶君儒,”水蒸氣在SiO2、TiO2、葡萄糖與麩胺酸次微米微粒上之非均勻相核凝現
象”，碩士論文，國立成功大學化工系，(2000).
31. C.T.R Wilson, Phil. Trans. A,189,265(1897).
32. J.J. Thomson, 3rd.Ed.,Vol1 (Cambridge University, Cambridge, 1928),99,320.
33. L. B. Loeb, A.F.Kip and A.W.Einarsson, J.Chen Phys.,6,265(1938).
34. F. He, P.K. Hopke, J. Chen. Phys.,99,9972(1993).
35. J.L. Katz, J.A. Fisk and V.M. Chakarov, J. Chem. Phys,101,2309(1994).
36. J.M.Mäkelä, A. Ukkonen, V. Jokinen, and J. Keskunen, J. Chem.
Phys.,105,1562(1996).
37. T. Seto, K. Okuyama,L. de Juan and F. de la Mora, J. Chem. Phys,107,1576
(1997).
38. W. J. Dunning, “Chemistry of the Solid State”, (Academic Press), NY.
(1955).
39. M. Volmer, ”Kinetic der Phasenbildung”, Verlag Th. Steinkopff, Dresden
(1939).
40. K. C. Russell, J. Chem. Phys., 50, 1809.
41. C.C. C. Chen, L. C. Hung, and H. K. Hsu , J. Colloid Interface Sci.,
157,465 (1993).
42. J. L. Katz and B. J. Ostermier, J. Chem. Phys., 47,478(1967).
43. M. Cloupeau and B. Prunet-Foch (1988), Journal of Electrostatics, 22,135
(1989).
44. J. Rosell-Llompart and J. Fernandez De La Mora(1994), J. Aerosol Sci. 25,
6 ,1093, 1994.
45. M. Cloupeau and B. Prunet-Foch (1994), J. Aerosol Sci. 25, 6,p. 1021, 1994.
46. W. Franklin Smyth, “Trends in analytical chemistry”, 1999, V.18, n.5,
p.335.
47. I. Wuled Lenggoro,*Kikuo Okuyama et al., J.Aerosol Sci. 31,1,121,(2000).
48. S. L. Kaufman, “Electrospray diagnostics performed by using sucrose and
proteins in the gas-phase electrophoretic mobility molecular” Special
Issue on Ion Formation Mechanisms in Electrospray, ed. S. Rutan and J. Fenn
(1999).
49. R.P.A.Hartman,D.J.Brunner,D.M.A.Camelot,J.C.M.Marijnissen and
B.Scarlett,J.Aerosol Sci.,2000,31,1,65.
50. T.K.Burayev and I.P. Vereshchagin,Fluid Mech.,Sov.Res.,1,56(1972).
51. D.P.H.Smith,IEEE Trans. Ind.Appl.,1A-22, 527(1986).
52. J.Zeleny,Phys.Rev.,10, 1-6(1917).
53. G. Taylor and M.D. Van Dyke,Proc. R. Soc.London, Ser.A, 313
,453(1969).
54. Vonnegut,B.and Neubauer,R.L.(1952), J.Colloid Sci., 7,616.
55. Michel Cloupeau and Bernard Prunet-Foch ,J.Aerosol Sci.,25,6,1021(1994).
56. C. H. Chen,*M.H.J.Emond et al ,J. Aerosol Sci.30,7,959(1999).
57. Model 3071A Electrostatic Classifier,TSI company.
58. Model 3077 Aerosol Neutralizer,TSI company.
59. J. L. Katz,”Condensation of a Supersaturated Vapor, I. “The homogenepus
Nucleation of the n-Alkanes”,J. Chem. Phys.,52,4733(1970).
60. Model 3934 Scanning Mobility Particle Sizer,TSI company.
61. R.J. Good, J.Phys. Chem.,61,810(1957).