Controllable Assembly, Structure And Properties Of One-dimensional Vanadium Oxide Nanomaterials

One-dimensional (1D) nanostructure materials, which have excellent physical and chemical properties because of the shape anisotropy, have potential applications in nanoelectronics, nanooptoelectronics, ultra-density storage, scanning probe microscope, stealth material and so on. Along with the artificial controlling of constitute, shape, size and assembly, 1D nanomaterials were applied sufficiently. Here we reviewed the recent development of 1D nanomaterials. 1D vanadium oxide nanomaterials were synthesized by rheological phase self-assembly and microemulsion approach. The nanostructure of vanadium oxide with different assembling technique was studied. Main study content and results are as follows:VO₂ nanorods were synthesized by rheological self-assembly method. The nanorods were non-uniform in size and aggregated greatly, and without organics on the surface. The vanadium oxide ultra-narrow nanowires with uniform size were synthesized by microemulsion method and self-assemblied to dandelion-like superstructure with no aggregation because of the organics on the surface. As reaction time extends or reactant concentration increase, the sizes of nanowires and dandelions increased with no changes in the shape. Furthermore, vanadium oxide nanowires could be monodispersed in chloroform to form stable colloidal solution. The photoluminescence (PL) property of the solution was studied. Via mechanism analysis, the rich photoluminescent bands were attributed to free exciton caused by charge transfer, bondage exciton caused by quantum confinement effect, electron transition from a level of nanometer state and defect energy level, separately.VO₂ nanorods prepared by rheological self-assembly method were functionalized via melted stearic acid toluene solution followed by microemulsion. These rods were rendered hydrophobic and monodispersed in chloroform. By the surface analysis of functionalized nanorods and dispersive theory of ultra-fine particle, the steric and electrostatic stabilization monodispersed mechanism was revealed.The assembling model of vanadium oxide nano-dandelion superstructure was established. The molecule self-assembly mechanism of template inducement, organic molecule inducement and hydrophobic interaction inducement was revealed. Based on the solvent volatilization self-assembly technique, and the chloroform and alcohol used as the solvent, the superstructure of vanadium oxide ultra-narrow nanowires was controlled from 3D dandelion-like to 2D side-by-side alignment, 3D rectangular grid and 1D bunchy-like, separately. The self-assembly behavior under different solvents and substrates was investigated. (001) crystal planes orientated and locally aligned VO₂ nanorods films are assembled by Langmuir-Blodgett (LB) technique. The Langmuir film behavior was revealed based on the analysis ofÏ€-A curve, morphology and X-ray diffraction. Furthermore, the magnetism property study demonstrated that the LB film of VO₂ nanorods is paramagnetism.