Skip to main content
SpringerLink
Log in

Hydrophobicity and drag reduction properties of surfaces coated with silica aerogels and xerogels

  • Original Paper
  • Published:
Journal of Sol-Gel Science and Technology Aims and scope Submit manuscript

Abstract

Superhydrophobic surfaces have application in self-cleaning, anti-fouling and drag reduction. Most superhydrophobic surfaces are constructed using complex fabrication methods. An alternative method is to use sol–gel methods to make hydrophobic aerogel and xerogel surfaces. In this work, hydrophobic silica aerogels and xerogels were made from the silica precursors tetramethoxysilane (TMOS) and methyltrimethoxysilane (MTMS) in volume ratios MTMS/TMOS of 0–75 % using a base-catalyzed recipe. Overall hydrophobicity was assessed using contact angle measurements on surfaces prepared from crushed aerogel and xerogel powders. The surfaces made from aerogels were super-hydrophobic (with contact angles of 167°–170°) for all levels of MTMS (10–75 %). Of the xerogel-coated surfaces, those made with 50 % MTMS were hydrophobic and with 75 % MTMS were superhydrophobic. Chemical hydrophobicity was assessed using Fourier transform infrared spectroscopy, which showed evidence of Si–CH3 and Si–C bonds in the aerogels and xerogels made with MTMS. Morphological hydrophobicity was assessed using SEM imaging and gas adsorption. The drag characteristics of the aerogel- and xerogel-coated surfaces were measured using a rotational viscometer. Under laminar flow conditions all of the hydrophobic aerogel-coated surfaces (10–75 % MTMS) were capable of capturing an air bubble, thereby reducing the drag on a horizontal rotating surface by 20–30 %. Of the xerogel-coated surfaces, only the one made from 75 % MTMS could capture a bubble, which led to 27 % drag reduction. These results imply that morphological differences between silica aerogels and xerogels, rather than any differences in their chemical hydrophobicity, give rise to the observed differences in hydrophobicity and drag reduction for the sol–gel-coated surfaces.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Scheme 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12

Similar content being viewed by others

References

  1. Li XM, Reinhoudt D, Crego-Calama M (2007) What do we need for a superhydrophobic surface? A review on the recent progress in the preparation of superhydrophobic surfaces. Chem Soc Rev 36:1350–1368

    Article  Google Scholar 

  2. Jeong A-Y, Koo S-M, Kim D-P (2000) Characterization of hydrophobic SiO2 powders prepared by surface modification on wet gel. J Solgel Sci Technol 19:483–487

    Article  Google Scholar 

  3. Aegerter MA, Almeida R, Soutar A, Tadanaga K, Yang H, Watanabe T (2008) Coatings made by sol-gel and chemical nanotechnology. J Solgel Sci Technol 47:203–236

    Article  Google Scholar 

  4. Rothstein JP (2011) Slip on superhydrophobic surfaces. Ann Rev Fluid Mech 42:89–109

    Article  Google Scholar 

  5. Samaha MA, Tafresuperhydrophobici HV, Gad-el-Hak M (2011) Superhydrophobic surfaces: from the lotus leaf to the submarine. Comptes Rendus Mécanique 340:18–34

    Article  Google Scholar 

  6. Voronov RS, Papavassiliou DV, Lee LL (2008) Review of fluid slip over superhydrophobic surfaces and its dependence on the contact angle. Ind Eng Chem Res 47:2455–2477

    Article  Google Scholar 

  7. Ou J, Perot B, Rothstein JP (2004) Laminar drag reduction in microchannels using ultrahydrophobic surfaces. Phys Fluids 16:4635–4643

    Article  Google Scholar 

  8. Daniello RJ, Waterhouse NE, Rothstein JP (2009) Drag reduction in turbulent flows over superhydrophobic surfaces. Phys Fluids. doi:10.1063/1.3207885

  9. Ogata S, Shimizu K (2011) Drag reduction by hydrophobic microstructures. J Environ Eng 6:291–301

    Article  Google Scholar 

  10. Watanabe K, Ogata S, Hirose A, Kimura A (2007) Flow characteristics of the drag reducing solid wall. J Environ Eng 2:108–114

    Article  Google Scholar 

  11. Gogte S, Vorobieff P, Truesdell R, Mammoli A, van Swol F, Shah P, Brinker CJ (2005) Effective slip on textured superhydrophobic surfaces. Phys Fluids. doi:10.1063/1.1896405

  12. Henoch C, Krupenkin TN, Kolodner P, Taylor JA, Hodes MS, Lyons AM, Peguero C, Breuer KS (2006) Turbulent drag reduction using superhydrophobic surfaces. In: Proceedings of the 3rd AIAA flow control conference AIAA2006-3192

  13. Aljallis E, Sarshar MA, Datla R, Hunter S, Simpson J, Sikka V, Jones A, Choi CH (2011) Measurement of hydrodynamic frictional drag on superhydrophobic flat plates in high reynolds number flows. In: Proceedings of the ASME 2011 IMECE, Denver, CO IMECE-63272

  14. Lee C, Kim CJ (2009) Maximizing the giant liquid slip on superhydrophobic microstructures by nanostructuring their sidewalls. Langmuir 25:12812–12818

    Article  Google Scholar 

  15. Anderson AM, Carroll MK (2011) Hydrophobic Silica Aerogels: Review of Synthesis, Properties and Applications. In: Aegerter MA, Leventis N, Koebel MM (eds) Aerogels handbook. Springer, New York

    Google Scholar 

  16. Rao AV, Pajonk G, Nadargi DY, Koebel MM (2011) Superhydrophobic and Flexible Aerogels. In: Aegerter MA, Leventis N, Koebel MM (eds) Aerogels handbook. Springer, New York

    Google Scholar 

  17. Samaha MA, Tafreshi HV, Gad-el-Hak M (2012) Effects of hydrostatic pressure on the drag reduction of submerged aerogel-particle coatings. Colloids Surf A Physicochem Eng Asp 399:62–70

    Article  Google Scholar 

  18. Anderson AM, Carroll MK, Green EC, Melville JT, Bono MS (2010) Hydrophobic silica aerogels prepared via rapid supercritical extraction. J Solgel Sci Technol 53:199–207

    Article  Google Scholar 

  19. Rao AV, Haranath D (1999) Effect of methyltrimethoxysilane as a synthesis component on the hydrophobicity and some physical properties of silica aerogels. Microporous Mesoporous Mater 30(2–3):267–273

    Google Scholar 

  20. Gauthier BM, Bakrania SD, Anderson AM, Carroll MK (2004) A fast supercritical extraction technique for aerogel fabrication. J Non Cryst Solids 350:238–243

    Article  Google Scholar 

  21. Carroll, MK, Anderson, AM, Gorka, CA (2014) Preparing silica aerogel monoliths via a rapid supercritical extraction method. J Vis Exp. doi:10.3791/51421

  22. Brunauer S, Emmett PH, Teller E (1938) Adsorption of gases in multimolecular layers. J Am Chem Soc 60:309–319

    Article  Google Scholar 

  23. Barrett EP, Joyner LG, Halenda PP (1951) The determination of pore volume and area distributions in porous substances. I. Computations from nitrogen isotherms. J Am Chem Soc 73:373–380

    Article  Google Scholar 

  24. Reichenauer G, Scherer G (2000) Nitrogen adsorption in compliant materials. J Non Cryst Solids 277:162–172

    Article  Google Scholar 

  25. Fidalgo A, Ciriminna R, Ilharco LM, Pagliaro M (2005) Role of the alkyl-alkoxide precursor on the structure and catalytic properties of hybrid sol–gel catalysts. Chem Mater 17:6686–6694

    Article  Google Scholar 

  26. Štandeker S, Novak Z, Knez Z (2007) Adsorption of toxic organic compounds from water with hydrophobic silica aerogels. J Colloid Interface Sci 310:362–368

    Article  Google Scholar 

  27. Martín L, Ossó JO, Ricart S, Roig A, García O, Sastre R (2008) Organo-modified silica aerogels and implications for material hydrophobicity and mechanical properties. J Mater Chem 18:207–213

    Article  Google Scholar 

  28. Bhagat SD, Oh CS, Kim YH, Ahn YS, Yeo JG (2007) Methyltrimethoxysilane based monolithic silica aerogels via ambient pressure drying. Microporous Mesoporous Mater 100:350–355

    Article  Google Scholar 

Download references

Acknowledgments

The authors would like to acknowledge undergraduate students Sean Maginess, Sarah Schinasi and Robin Barabasz for initial work on the project. They also thank Yi Cao for help making the aerogels, and Stephen J. Juhl and Ryan M. Bouck for SEM imaging. The Union College Aerogel Laboratory has been funded by grants from the National Science Foundation (NSF MRI CTS-0216153, NSF RUI CHE-0514527, NSF MRI CMMI-0722842, NSF RUI CHE-0847901, NSF RUI DMR-1206631 and NSF MRI CBET-1228851). This material is based upon work supported by the NSF under Grant No. CHE-0847901. The SEM instrument was funded through grants from the National Science Foundation (NSF MRI 0619578) and New York State Assembly RESTORE-NY.

Author information

Authors and Affiliations

  1. Engineering Division, Union Graduate College, Schenectady, NY, USA

    Justin E. Rodriguez

  2. Department of Mechanical Engineering, Union College, Schenectady, NY, USA

    Ann M. Anderson

  3. Department of Chemistry, Union College, Schenectady, NY, USA

    Mary K. Carroll

Authors
  1. Justin E. Rodriguez
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Ann M. Anderson
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Mary K. Carroll
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Ann M. Anderson.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Rodriguez, J.E., Anderson, A.M. & Carroll, M.K. Hydrophobicity and drag reduction properties of surfaces coated with silica aerogels and xerogels. J Sol-Gel Sci Technol 71, 490–500 (2014). https://doi.org/10.1007/s10971-014-3388-3

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10971-014-3388-3

Keywords

Search

Navigation