Filling carbon nanopipes with functionalized nanoparticles

In this paper, we show a relatively simple, inexpensive, reproducible, scalable and fast method of filling the carbon nanotubes with functional nanoparticles, in particular, magnetic and gold nanoparticles. This technique opens an opportunity for functionalization of carbon nanotubes based on the phenomenon of spontaneous penetration of wetting fluids into capillaries. In our expts., the no. of magnetic grains in the tubes varies between N .apprx. 104 - 105. The filled CNTs follow the applied magnetic field, thus manifesting their magnetic nature. We showed that the yield of magnetic nanotubes after wet filling was close to 100%. Controllable manipulation of magnetic nanotubes with micromagnets points to a straightforward way for utilization of these nanoneedles in different nanofluidic and electronic devices. We filled CNTs with gold nanoparticles and com. available ferromagnetic particles. The gold nanoparticles were synthesized from hydrochloroauric acid. TEM micrographs show a high fraction of nanoparticles in the CNTs. These two types of fillers, magneticand gold nanoparticles, are of interest for nanoelectronics. They are expected to provide better cond., magnetic properties and thermal cond. for the nanowires made of carbon nanotubes. Generally, the paper provides a procedure of making nanotubes functional. Other particulate fluids, emulsions, and polymer solns. can be used to fill nanotubes and transform them into multifunctional nanostructures.