Real-time observation of template-assisted colloidal aggregation and colloidal dispersion under an alternating electric field

doi:10.1088/1674-1056/20/7/078102

摘要/Abstract

摘要： A fascinating colloid phenomenon was observed in a specially designed template-assisted cell under an alternating electrical field. Most colloidal particles experienced the processes of aggregation, dispersion and climbing up to the plateaus of the patterns pre-lithographed on the indium tin oxide glass as the frequency of the alternating electrical field increased. Two critical frequencies f_crit1 ≈ 15 kHz and f_crit2 ≈ 40 kHz, corresponding to the transitions of the colloid behaviour were observed. When f < 15 kHz, the particles were forced to aggregate along the grooves of the negative photoresist patterned template. When 15 kHz < f < 40 kHz, the particle clusters became unstable and most particles started to disperse and were blocked by the fringes of the negative photoresist patterns. As the frequency increased to above 40 kHz, the majority of particles started to climb up to the plateaus of the patterns. Furthermore, the dynamics analysis for the behaviour of the colloids was given and we found out that positive or negative dielectrophoresis force, electrohydrodynamic force, particle—particle interactions and Brownian motion change with the frequency of the alternating electric field. Thus, changes of the related forces affect or control the behaviour of the colloids.

Abstract: A fascinating colloid phenomenon was observed in a specially designed template-assisted cell under an alternating electrical field. Most colloidal particles experienced the processes of aggregation, dispersion and climbing up to the plateaus of the patterns pre-lithographed on the indium tin oxide glass as the frequency of the alternating electrical field increased. Two critical frequencies f_crit1 ≈ 15 kHz and f_crit2 ≈ 40 kHz, corresponding to the transitions of the colloid behaviour were observed. When f < 15 kHz, the particles were forced to aggregate along the grooves of the negative photoresist patterned template. When 15 kHz < f < 40 kHz, the particle clusters became unstable and most particles started to disperse and were blocked by the fringes of the negative photoresist patterns. As the frequency increased to above 40 kHz, the majority of particles started to climb up to the plateaus of the patterns. Furthermore, the dynamics analysis for the behaviour of the colloids was given and we found out that positive or negative dielectrophoresis force, electrohydrodynamic force, particle—particle interactions and Brownian motion change with the frequency of the alternating electric field. Thus, changes of the related forces affect or control the behaviour of the colloids.

Key words: template-assisted, aggregation, dispersion, dynamics analysis

中图分类号: (Methods of crystal growth; physics and chemistry of crystal growth, crystal morphology, and orientation)

81.10.-h

82.70.-y (Disperse systems; complex fluids) 82.70.Dd (Colloids) 82.70.Kj (Emulsions and suspensions)

李超荣, 李书文, 梅洁, 徐庆, 郑莹莹, 董文钧. Real-time observation of template-assisted colloidal aggregation and colloidal dispersion under an alternating electric field[J]. 中国物理B, 2011, 20(7): 78102-078102.

Li Chao-Rong(李超荣), Li Shu-Wen(李书文), Mei Jie(梅洁), Xu Qing(徐庆), Zheng Ying-Ying(郑莹莹), and Dong Wen-Jun(董文钧) . Real-time observation of template-assisted colloidal aggregation and colloidal dispersion under an alternating electric field[J]. Chin. Phys. B, 2011, 20(7): 78102-078102.

参考文献 30

[1]	Arora A K and Tata B V R 1996 Ordering and Phase Transitions in Charged Colloids (New York: VCH publisher Inc.) p. 1
[2]	Zhang K Q and Liu X Y 2004 Nature 429 739
[3]	Zhang K Q and Liu X Y 2006 Phys. Rev. Lett. 96 105701
[4]	Xie R G and Liu X Y 2009 J. Am. Chem. Soc. 131 4976
[5]	Feng T H, Dai Q F, Wu L J, Guo Q, Hu W and Lan S 2008 Chin. Phys. B 17 4533
[6]	Denkov N D, Velev O D, Kralchevsky P A, Ivanov I B, Yoshimura H and Nagayama K 1992 Langmuir 8 3183
[7]	Erb R M, Son1 H S, Samanta B, Rotello V M and Yellen B B 2009 Nature 457 999
[8]	Williams S J, Kumar A and Wereley S T 2009 Phys. Fluids 21 091104
[9]	Yan H T, Wang M, Ge Y X and Yu P 2009 Chin. Phys. B 18 2389
[10]	Zhang L F and Huang J P 2010 Chin. Phys. B 19 024213
[11]	Zhang T H and Liu X Y 2009 Angew. Chem. Int. Ed. 48 1308
[12]	Zhang T H and Liu X Y 2007 J. Phys. Chem. C 111 1342
[13]	Zhang T H and Liu X Y 2006 Appl. Phys. Lett. 89 261914
[14]	Liu Y, Narayanan J and Liu X Y 2006 J. Chem. Phys. 124 124906
[15]	Nadal F, Argoul F, Kestener P, Pouligny B, Ybert C and Ajdari A 2002 Eur. Phys. J. E 9 387
[16]	Nadal F, Argoul F, Hanusse P, Pouligny B and Ajdari A 2002 Phys. Rev. E 65 061409
[17]	Allard M, Sargent E H, Lewis P C and Kumacheva E 2004 Adv. Mater. 16 15
[18]	Yeh S R, Seul M and Shraiman B I 1997 Nature 386 57
[19]	Kaler K, Xie J P, Jones T B and Paul R 1992 Biophys. J. bf 63 58
[20]	Ramos A, Morgan H, Green N G and Castellanos A 1999 J. Colloid Interface Sci. 217 420
[21]	Green N G and Morgan H 1998 J. Phys. D: Appl. Phys. 31 L25
[22]	Green N G, Ramos A and Morgan H 2000 J. Phys. D: Appl. Phys. 33 632
[23]	Li J F, Yu W H, Chen C S and Wei W C 2003 Technical Proceedings of the 2003 Nanotechnology Conference and Trade Show, San Francisco, Febuary 2, 2003 p. 566
[24]	Pohl H A 1951 J. Appl. Phys. 22 869
[25]	Jones T B 1995 Electromechanics of Particles (New York: Cambridge University Press) pp. 5—82
[26]	Green N G and Morgan H 1997 J. Phys. D: Appl. Phys. 30 L41
[27]	Russel W B, Saville D A and Schowalter W R 1989 Colloidal Dispersions (New York: Cambridge University Press) pp. 1—454
[28]	Trau M, Saville D A and Aksay I A 1997 Langmuir 13 6375
[29]	Ristenpart W D, Aksay I A and Saville D A 2004 Phys. Rev. E 69 021405
[30]	Ristenpart W D, Aksay I A and Saville D A 2007 J. Fluid Mech. 575 83