Influence of the cation alkyl chain length of imidazolium-based room temperature ionic liquids on the dispersibility of TiO2 nanopowders

  • Alexandra Wittmar
  • Martyna Gajda
  • Devendraprakash Gautam
  • Udo Dörfler
  • Markus Winterer
  • Mathias Ulbricht
Research Paper


The influence of the length of the cation alkyl chain on the dispersibility by ultrasonic treatment of TiO2 nanopowders in hydrophilic imidazolium-based room temperature ionic liquids was studied for the first time by dynamic light scattering and advanced rheology. TiO2 nanopowders had been synthesized by chemical vapor synthesis (CVS) under varied conditions leading to two different materials. A commercial nanopowder had been used for comparison. Characterizations had been done using transmission electron microscopy, X-ray diffraction, nitrogen adsorption with BET analysis, and FT-IR spectroscopy. Primary particle sizes were about 6 and 8 nm for the CVS-based and 26 nm for the commercial materials. The particle size distribution in the dispersion was strongly influenced by the length of the cation alkyl chain for all the investigated powders with different structural characteristics and concentrations in the dispersion. It was found that an increase of the alkyl chain length was beneficial, leading to a narrowing of the particle size distribution and a decrease of the agglomerate size in dispersion. The smallest average nanoparticle sizes in dispersion were around 30 nm. Additionally, the surface functionality of the nanoparticles, the concentration of the solid material in the liquid, and the period of ultrasonic treatment control the dispersion quality, especially in the case of the ionic liquids with the shorter alkyl chain. The influence of the nanopowders characteristics on their dispersibility decreases considerably with increasing cation alkyl chain length. The results indicate that ionic liquids with adapted structure are candidates as absorber media for nanoparticles synthesized in gas phase processes to obtain liquid dispersions directly without redispergation.


Nanoparticles dispersions Ionic liquids Rheology 



The financial support through the NanoEnergieTechnikZentrum (NETZ), an application-focused research project partially financed by the state of North Rhine-Westphalia and the European Union, is kindly acknowledged. We gratefully acknowledge the collaboration with Dr. W. Meyer-Zaika (TEM characterization) at the University of Duisburg-Essen.

Supplementary material

11051_2013_1463_MOESM1_ESM.doc (1.9 mb)
Supplementary material 1 (DOC 1983kb)


  1. Akurati KK, Bahattacharya SS, Winterer M, Hahn H (2006) Synthesis, characterization and sintering of nanocrystalline titania powders produced by chemical vapor synthesis. J Phys D Appl Phys 39:2248–2254. doi: 10.1088/0022-3727/39/10/037 CrossRefGoogle Scholar
  2. Arantes TM, Leao KV, Tavares MBI, Ferreira AG, Longo E, Camargo ER (2009) NMR study of styrene-butadiene rubber (SBR) and TiO2 nanocomposites. Polym Testing 28:490–494. doi: 10.1016/j.polymtesting.2009.03.011 CrossRefGoogle Scholar
  3. Bonhôte P, Dias AP, Papagiorgiou N, Kalyanasundaram K, Grätzel M (1996) Hydrophobic, highly conductive ambient-temperature molten salts. Inorg Chem 35:1168–1178. doi: 0020-1669/96/1335-1168 CrossRefGoogle Scholar
  4. Branco LC, Rosa JN, Moura Ramones JJ, Alfonsi CAM (2002) Preparation and characterization of new room temperature ionic liquids. Chem Eur J 8:3671–3677. doi: 10.1002/1521-3765(20020816 CrossRefGoogle Scholar
  5. Burell GL, Dunlop NF, Separovic F (2010) Non-Newtonian viscous shear thinning in ionic liquids. Soft Matter 6:2080–2086. doi: 10.1039/b916049n CrossRefGoogle Scholar
  6. Buzzeo MC, Evans RG, Compton RG (2004) Non-haloaluminate room temperature ionic liquids in electrochemistry– a review. Chem Phys Chem 5:1106–1120. doi: 10.1002/cphc.200301017 CrossRefGoogle Scholar
  7. Chen X, Mao SS (2007) Titanium dioxide nanomaterials: synthesis, properties, modifications and applications. Chem Rev 107:2859–2891. doi: 10.1021/cr0500535 Google Scholar
  8. Chiappe C, Pieracini D (2005) Ionic liquids: solvent properties and organic reactivity. J Phys Org Chem 8:275–297. doi: 10.1002/poc.836 CrossRefGoogle Scholar
  9. Djenadic R, Winterer M (2012) Nanoparticles from the gasphase: formation, structure, properties. In: Lorke A, Winterer M, Schmechel R, Schulz C (Eds.), Springer, New York, in printGoogle Scholar
  10. Dupont J (2011) From molten salts to ionic liquids: a “nano” journey. Acc Chem Res 44:1223–1231. doi: 10.1021/ar2000937 CrossRefGoogle Scholar
  11. Dzyuba S, Bartsch RA (2002) Influence of structural variations in 1-alkyl(aralkyl)-3-methylimidazolium hexafluorophosphates and Bis(trifluoromethyl-sulfonyl)imides on physical properties of ionic liquids. Chem Phys Chem 3:161–166. doi: 10.1002/1439-7641(20020215 CrossRefGoogle Scholar
  12. Elim HI, Ji V, Yuwono AH, Xue JM, Wang J (2003) Ultrafast optical nonlinearity in poly(methylmethacrylate)-TiO2 nanocomposites. Appl Phys Lett 82:2691–2693. doi: 10.1063/1.1568544 CrossRefGoogle Scholar
  13. Endres F, Zein El Abedin S (2006) Air and water stable ionic liquids in physical chemistry. Phys Chem Chem Phys 8:2101–2116. doi: 10.1039/B600519P CrossRefGoogle Scholar
  14. Greaves TL, Drummond CJ (2008) Protic ionic liquids: properties and applications. Chem Rev 108:206–237. doi: 10,1021/cr068040u CrossRefGoogle Scholar
  15. Hapiot P, Lagrost C (2008) Electrochemical reactivity in room temperature ionic liquids. Chem Rev 108:2238–2264. doi: 10.1021/cr068686 CrossRefGoogle Scholar
  16. Holbrey JD, Seddon KR (1999) The phase behaviour of 1-alkyl-3-methylimidazolium tetrafluoroborates; ionic liquids and ionic crystals, J Chem Soc Dalton Trans. 2133–2139. doi: 10.1039/A902818H
  17. Jiang J, Oberdörster G, Biswas P (2009) Characterization of size, surface charge, and agglomeration state of nanoparticles dispersions for toxicological studies. J Nanopart Res 11:77–89. doi: 10.1007/s11051-008-9446-4 CrossRefGoogle Scholar
  18. Kwong CY, Choy WCH, Djurisic AB, Chui PC, Cheng KW, Chan WK (2004) Poly(3-hexylthiophene): TiO2 nanocomposites for solar cell applications. Nanotechnol 15:1156–1161. doi: 10.1088/0957-4484/15/9/008 CrossRefGoogle Scholar
  19. Lu J, Yan F, Texter J (2009) Advanced applications of ionic liquids in polymer science. Progr Polym Sci 34:431–448. doi: 10.1016/j.progpolymsci.2008.12.001 CrossRefGoogle Scholar
  20. Mandzy N, Grulke E, Druffel T (2005) Breakage of TiO2 agglomerates in electrostatically stabilized aqueous dispersions. Powder Technol 160:121–126. doi: 10.1016/j.powtec.2005.08.020 CrossRefGoogle Scholar
  21. Marsh KN, Deev A, Wu ACT, Tran E, Klamt A (2002) Room temperature ionic liquids as replacement for convenitional solvents–a review, Korean J. Chem Eng 19:357–362.Google Scholar
  22. Meng X, Zhang Z, Luo N, Cao S, Yang M (2011) Transparent poly(methylmethacrylate)/TiO2 nanocomposites for UV-shielding applications. Polym Sci Ser A 53:977–983. doi: 10.1134/S096554X11100099 CrossRefGoogle Scholar
  23. Nichols G, Byard S, Bloxham MJ, Botteril J, Dawson NJ, Dennis A, Diart V, North NC, Sherwood JD (2002) A review of the terms agglomerate and aggregate with recommendation for nomenclature used in powder and particles characterization. J Pharm Sci 91:2103–2109. doi: 10.1002/jps.10191 CrossRefGoogle Scholar
  24. Nussbaumer RJ, Caseri WR, Smith P, Tervorst T (2003) Polymer–TiO2 nanocomposites: a route towards visually transparent broadband UV filters and high refractive index materials. Macromol Mater Eng 288:44–49. doi: 10.1002/mane.200290032 CrossRefGoogle Scholar
  25. Pratsinis SE (1988) Flame aerosol synthesis of ceramic powders. Prog Energ Combust Sci 24:197–219CrossRefGoogle Scholar
  26. Reddy RG (2006) Ionic liquids: how well do we know them? J Phase Eq Diffusion 27:210–211. doi: 10.1361/154770306x110087 CrossRefGoogle Scholar
  27. Sakhna OV, Goldenberg LM, Stumpe J, Smirnov TN (2007) Surface modified ZrO2 and TiO2 nanoparticles embedded in organic photopolymers for high effective and UV-stable volume halograms. Nanotechnol 18: 105704 (7p.). doi: 10.1088/0597-4484/18/10/105704
  28. Seddon KR (1997) Ionic liquids for clean technology. J Chem Tech Biotechnol 68:351–356CrossRefGoogle Scholar
  29. Swatloski RP, Holbrey JD, Rogers RD (2003) Ionic liquids are not always green: hydrolysis of 1-butyl-3-methylimidazolium hexafluorophosphate. Green Chem 5:361–363. doi: 10.1039/B4400A CrossRefGoogle Scholar
  30. Tao P, Li Y, Rungta A, Viswanath A, Gao J, Benicewicz BC, Siegel RW, Schadler LS (2011) TiO2 nanocomposites with high refractive index and transparency. J Mater Chem 21:18623–18629. doi: 10.1039/c1jm13093e CrossRefGoogle Scholar
  31. Tokuda H, Hayamizu K, Ishii K, Abu Bin Hasan Susan M, Watanabe M (2004) Physicochemical properties and structures of room temperature ionic liquids.I. Variation of anionic species. J Phys Chem B 108: 16593. doi: 10.1021/jp047480r
  32. Tokuda H, Hayamizu K, Ishii K, Abu Bin Hasan Susan M, Watanabe M (2005) Physicochemical properties and structures of room temperature ionic liquids.2. Variation of alkyl chain length in imidazolium cation. J.Phys Chem. B 109:6103–6110. doi: 10.1021/jp044626d CrossRefGoogle Scholar
  33. Torimoto T, Tsuda T, Okazaki K, Kuwabata S (2010) New frontiers in materials science opened by ionic liquids. Adv Mater 22:1196–1221. doi: 10.1002/adma.200902184 CrossRefGoogle Scholar
  34. Trung VQ, Huyen DN (2009) Synthesis, properties and application of polyindole/TiO2 nanocomposites. J Phys Conf Ser 187: 012058 (6p.). doi: 10.1088/1742-6596/187/1/012058
  35. Ueno K, Watanabe M (2011) From colloidal stability in ionic liquids to advanced soft materials using unique media. Langmuir 27:9105–9115. doi: 10.1021/la103942f CrossRefGoogle Scholar
  36. Ueno K, Inaba A, Kondoh M, Watanabe M (2008) Colloidal stability of bare and polymer-grafted silica nanoparticles in ionic liquids. Langmuir 24:5253–5259. doi: 10.1021/la704066v CrossRefGoogle Scholar
  37. Welton T (1999) Room temperature ionic liquids. Solvents for synthesis and catalysis. Chem Rev 99:2071–2083. doi: 10.1021/cr980032t CrossRefGoogle Scholar
  38. Winterer M (2002) Nanocrystalline ceramics–synthesis and structure, vol 53., Springer Series in Materials ScienceSpringer, Heidelberg. doi: 3-540-43433-X CrossRefGoogle Scholar
  39. Wittmar A, Ulbricht M (2012) Dispersions of various titania nanoparticles in two different ionic liquids. Ind Eng Chem Res 51:8425–8433. doi: 10.1021/ie203010x CrossRefGoogle Scholar
  40. Wittmar A, Ruiz-Abad D, Ulbricht M (2012) Dispersions of silica nanoparticles in ionic liquids investigated with advanced rheology. J Nanoparticle Res 14:651–660. doi: 10.1007/s11051-011-0651-1 CrossRefGoogle Scholar
  41. Ye C, Liu W, Chen Y, Yu L (2001) Room-temperature ionic liquids: a novel versatile lubricant. Chem Commun 21:2244–2245. doi: 10.1039/b106935g CrossRefGoogle Scholar
  42. Zhang H, Hong K, Mays JW (2002) Synthesis of block copolymers of styrene and methacrylate by conventional free radical polymerization in room temperature ionic liquids. Macromolecules 35:5738–5741. doi: 10.1021/ma025518x CrossRefGoogle Scholar
  43. Zhao D, Wu M, Kou Y, Min E (2002) Ionic liquids: applications in catalysis. Cat Today 74:157–189CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  • Alexandra Wittmar
    • 1
    • 3
  • Martyna Gajda
    • 1
  • Devendraprakash Gautam
    • 2
    • 3
  • Udo Dörfler
    • 2
    • 3
  • Markus Winterer
    • 2
    • 3
  • Mathias Ulbricht
    • 1
    • 3
  1. 1.Lehrstuhl für Technische Chemie IIUniversität Duisburg-EssenEssenGermany
  2. 2.Nanoparticle Process TechnologyUniversität Duisburg-EssenDuisburgGermany
  3. 3.CeNIDE–Center for Nanointegration Duisburg-EssenDuisburgGermany

Personalised recommendations