Preparation And Characterization Of Low Dimensional Functional Organic Nanomaterials

Organic charge-transfer complexes of Ag-TCNQ and Cu-TCNQ (TCNQ= 7,7,8,8-tetracyanoquinodimethane) are of considerable current interest due to their unique electrical, magnetic and optical bistable properties, and have been applied as electrical micro-device, molecular device and large capacity recording media. In the present study, charge-transfer complexes nanowires of M-TCNQ(M=Ag, Cu) were prepared by organic vapor-solid-phase and solution-solid-phase reactions, and the crystalline growth rules were discussed which were based on the effects of reaction pattern and condition on the morphology of M-TCNQ.It was found that M-TCNQ complexes crystallize mainly taking on one dimensional orientation. Slinger, longer and more density cluster of nanowire could be obtained when assuming vapor-solid reaction with higher temperature and longer reaction time. The results of XRD, XPS, IR show that the Cu-TCNQ nanowire possesses phase I structure, while Ag-TCNQ nanowire is corresponding to its phase II structure.The conductivity of Cu-TCNQ nanowire is determined to be about 2×10^-3 S/cm based on its current-voltage measurement data. The turn-on field and threshold field of Cu-TCNQ nanowires increase with the reaction time increasing from 15min to several hours. Ag-TCNQ kept 60min at 100℃ and Cu-TCNQ kept 15min at 150℃ , the nanowire films exhibit a turn-on field of 9.1 and 7.4 V/μm, respectively. The relationship between morphologies of M-TCNQ complexes and their field emission properties shows that the nanowires with tips structure, smaller diameter and suitable density have better field emission property.Different aggregation states of silver or copper were employed to react with TCNQ solution. Most of the productions display one-dimensional micr/nanowires/rod morphology. Productions with more regular morphology can be obtained from lower concentration of solution; and the particle radius and length increase with the increase of reaction time. It is also found that Ag-TCNQ of helical structure could be achieved from "no-free" silver particle, which is different from that of Cu-TCNQ.[60]Fullerene aqueous colloid and [60]fullerene nanoparticles were prepared by ultrasonic technique. The properties of C₆₀ colloid and nanoparticles were characterized by UV-vis spectra and TEM. The results show that the concentration of [60]fullerene aqueous colloid and the diameters of [60]fullerene nanoparticles were controlled by adjusting the outer power of ultrasonic at the same o/w ratio. [60]fullerene aqueous colloid solution with particle size of 8 nm covered with hydrated shell is able to obtained using 800 W outer power of ultrasonic.