Supramolecular assembly of single-walled carbon nanotubes at air-solid interface
We formed a stable and reversible Langmuir film (LF) of bundles of unfunctionalized single-walled carbon nanotubes (SWCNTs) at the air–water interface. The film exhibits gas-like and liquid-like phases. The Raman spectrograph of Langmuir–Blodgett (LB) film of single layer of SWCNTs on Si/SiO2 substrate shows the characteristic G, D, and radial breathing mode frequencies of the single-walled carbon nanotubes. Using atomic force microscope (AFM) in spreading resistance imaging mode, we obtained a dependence of target surface pressure on the assembly of SWCNTs in the LB films. The film deposited at very low surface pressure (0.5 mN/m) exhibited an assembly wherein the long axis of the nanotube bundles aligned in the direction of deposition. The LB films deposited in the liquid-like phase of the SWCNTs exhibited supramolecular donut structure. The average width of the SWCNTs was around 30 nm. The current–voltage characterization of the local structures of the LB films using the conducting AFM probe indicates semi-metallic and metallic nature of the donut and the hole in the donut (nanopore), respectively. Such supramolecular assembly of the SWCNTs can find application in the fabrication of the devices like sensors, photochemical cells, batteries, etc.
KeywordsLangmuir film Langmuir–Blodgett films Single-walled carbon nanotubes Atomic force microscopy Supramolecular donut structure Two-dimensional nanostructure
Authors from BITS Pilani are thankful the University Grants Commission, India for its support through Special Assistance Programme. Thanks are also due to Department of Science and Technology, India. We are thankful to Dr. Chandra Shekhar, Director CSIR-CEERI Pilani for his kind approval for carrying out this collaborative work.
- Gaines GL (1966) Insoluble monolayers at liquid-gas interfaces. Interscience, New YorkGoogle Scholar
- Gupta RK, Manjuladevi V (2012b) Molecular interactions at interfaces. In: Meghea A (ed) Molecular interactions. InTech, Croatia, pp 81–104Google Scholar
- Jia L, Zhang Y, Li J, You C, Xie E (2008) Aligned single-walled carbon nanotubes by Langmuir–Blodgett technique. J Appl Phys 104:074318-1–074318-6. doi: 10.1063/1.2996033
- Kostarelos K, Lacerda L, Pastorin G, Wu W, Wieckowski S, Luangsivilay J, Godefroy S, Pantarotto D, Briand JP, Muller S, Prato M, Bianco A (2007) Cellular uptake of functionalized carbon nanotubes is independent of functional group and cell type. Nature Nanotechnol 2:108–113. doi: 10.1038/nnano.2006.209 CrossRefGoogle Scholar
- Nguyen TT, Nguyen SU, Phuong DT, Nguyen DC, Mai AT (2011) Dispersion of denatured carbon nanotubes by using a dimethylformamide solution. Adv Nat Sci Nanosci Nanotechnol 2:035015-1–035015-4. doi: 10.1088/2043-6262/2/3/035015
- Roberts G (1990) Langmuir–Blodgett Films. Springer-Verlag, New YorkGoogle Scholar
- Saito R, Dresselhaus G, Dresselhaus MS (2007) Physical properties of carbon nanotubes. Imperial College Press, LondonGoogle Scholar
- Shimoda H, Oh SJ, Geng HZ, Walker RJ, Zhang XB, McNeil LE, Zhou O (2002) Self assembly of carbon nanotubes. Adv Mater 14:899–901. doi: 10.1002/1521-4095(20020618)14:12<899:AID-ADMA899>3.0.CO;2-2 CrossRefGoogle Scholar
- Ulman A (1991) An introduction to ultrathin organic films-from Langmuir–Blodgett to self assembly. Academic Press, New YorkGoogle Scholar
- Wei Y, Weng D, Yang Y, Zhang X, Jiang K, Liu L, Fan S (2006) Efficient fabrication of field electron emitters from the multiwalled carbon nanotube yarns. Appl Phys Lett 89:063101-1–063101-3 doi: 10.1063/1.2236465