Hostname: page-component-76fb5796d-vfjqv Total loading time: 0 Render date: 2024-04-25T16:44:44.924Z Has data issue: false hasContentIssue false
  • English
  • Français

Solvent behavior in hydrophobic silica nanotubes

Published online by Cambridge University Press:  26 February 2011

Douglas English ,
Charles Luckett ,
Karthik Jayaraman ,
Sang Bok Lee ,
Sang Jun Son  and
Kenji Okamoto
Douglas English
Affiliation:
denglish@umd.edu, University Of Maryland, Bldg 091, College Park, MD, 20742, United States
Charles Luckett
Affiliation:
cluckett@umd.edu, University Of Maryland-College Park
Karthik Jayaraman
Affiliation:
karthik.jayaraman@bms.com, University Of Maryland-College Park
Sang Bok Lee
Affiliation:
slee@umd.edu, University Of Maryland-College Park
Sang Jun Son
Affiliation:
triaza@gmail.com, University Of Maryland-College Park
Kenji Okamoto
Affiliation:
okamotok@kuchem.kyoto-u.ac.jp
Get access

Abstract

Template-synthesized silica nanotubes offer a unique and interesting opportunity for studying fluids in confined spaces. Their versatility stems from our ability to independently vary the inside diameter and surface chemistry. In this work we investigated capillarity for binary mixtures of water and methanol in hydrophobic nanotubes with internal diameters of both 30 and 170 nm. An improved sol-gel template synthesis process was used to prepare silica nanotubes with smooth and uniform walls within the pores of alumina template membranes. The pore diameter and thickness of the template membrane determined the outer diameter and length of the nanotube, respectively. The number of deposition cycles controlled the wall thickness. An octadecylsilane coating was selectively applied to the nanotube interior while leaving the nanotube exterior unmodified. The interiors of hydrophobic nanotubes prepared in this way were then labeled with trace amounts of adsorbed dyes. The diffusion of the dye molecules inside individual immersed nanotubes was investigated using fluorescence recovery after photobleaching (FRAP) experiments. Dye diffusion was used to determine the wettability of the nanotube interior as a function of solvent composition. Several important observations are reported here. First, a clear transition is observed in which all nanotubes change from non-wetting to wetting when the methanol mole fraction approaches 0.5. This transition appears at the same solvent composition for both nanotube sizes. Interestingly, the Young-Laplace equation fails to accurately predict the wetting transition. The difference between the observed and predicted wetting transition may be due to reliance on macroscopic values of contact angles or surface tensions in our predictions or may be related to the presence of liquid phase instability, dry-layers or non-spherical menisci within the hydrophobic pore.

Keywords

nanostructurefluidicslaser-induced reaction
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 899: Symposium N – Dynamics in Small Confining Systems VIII , 2005 , 0899-N08-06
Copyright
Copyright © Materials Research Society 2006

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

[1] Martin, C. R., Science 266, 1961–1966, (1994).Google Scholar
[2] Lakshmi, B. B., Patrissi, C. J., and Martin, C. R., Chem. Mater. 9, 2544–2550, (1997).Google Scholar
[3] Wirtz, M., Parker, M., Kobayashi, Y., and Martin, C. R., Chem. Eur. J. 8, 3573–3578, (2002).Google Scholar
[4] Martin, C. R., and Kohli, P., Nat. Rev. Drug Discovery 2, 29–37, (2003).Google Scholar
[5] Jayaraman, K., Okamoto, K., Son, S. J., Luckett, C., Gopalani, A., , L. S. B., and English, D. S., J. Am. Chem. Soc. 127, 17385–17392, (2005).Google Scholar
[6] Sobolev, V. D., Churaev, N. V., Velarde, M. G., and Zorin, Z. M., J. Colloid Interface Sci. 222, 51–54, (2000).Google Scholar
[7] Okamoto, K., Shook, C. J., Bivona, L., Lee, S. B., and English, D. S., Nano Lett. 4, 233–239, (2004).Google Scholar
[8] Tas, N. R., Mela, P., Kramer, T., Berenschot, J. W., and van den Berg, A., Nano Lett. 3, 1537–1540, (2003).Google Scholar
[9] Adamson, A. W., and Gast, A. P., Physical Chemistry of Surfaces, (John Wiley & Sons, Inc, New York, 1997) p 12.Google Scholar
[10] Young, T. F., and Harkins, W. D., International Critical Tables of Numerical Data, (McGraw-Hill, New York, 1926) p. 147.Google Scholar
[11] Helmy, R., Kazakevich, Y., Ni, C., and Fadeev, A. Y., J. Am. Chem. Soc. 127, 12446–12447, (2005).Google Scholar
[12] Eijkel, J. C. T., and van den Berg, A., Lab Chip 5, 1202–1209, (2005).Google Scholar
[13] Sivanesan, P., Okamoto, K., English, D., Lee, C. S., and DeVoe, D. L., Anal. Chem. 77, 2252–2258, (2005).Google Scholar
[14] Luzar, A., J. Phys. Chem. B 108, 19859–19866, (2004).Google Scholar
[15] Lum, K., Chandler, D., and Weeks, J. D., J. Phys. Chem. B 103, 4570–4577, (1999).Google Scholar
[16] ten Wolde, P. R., Sun, S. X., and Chandler, D., Phys. Rev. E 65, 011201–1 to 011201–9, (2002).Google Scholar
[17] Maibaum, L., and Chandler, D., J. Phys. Chem. B 107, 1189–1193, (2003).Google Scholar
[18] Giaya, A., and Thompson, R. W., J. Chem. Phys. 117, 3464–3475, (2002).Google Scholar
[19] Ball, P., Nature (London) 423, 25–26, (2003).Google Scholar
[20] Masuda, H., and Fukuda, K., Science 268, 1466–1468, (1995).Google Scholar
[21] Li, A. P., Muller, F., Birner, A., Nielsch, K., and Gosele, U., J. Appl. Phys. 84, 6023–6026, (1998).Google Scholar
[22] Kovtyukhova, N. I., Mallouk, T. E., and Mayer, T. S., Adv. Mater. 15, 780–785, (2003).Google Scholar