As a type of thin film,two dimensional(2D) reticulate architectures built of freestanding single-walled carbon nanotube(SWCNT) bundles are suitable for scalable integration into devices and nanocomposites for many applications.The superior properties of these films,such as optical transparency,unique electrical properties and mechanical flexibility,result not only from the outstanding properties of individual SWCNTs but also from the collective behavior of the individual tubes,with additional properties arising from the tube-tube interactions.In this review,the synthesis,structure and fundamental properties,such as conductivity,transparency,optical nonlinearity and mechanical performance,of "freestanding SWCNT bundle network" thin films and nanocomposites,as well as their application as supercapacitors are highlighted.Some long-standing problems and topics warranting further investigation in the near future are addressed.
Research interest in ZnO nanostructures derives from their excellent luminescent properties and availability of low cost fabricating and processing,which hold promise for the development of electronic and optoelectronic nanodevices.In this review,we focus on the progress in synthesis,properties and nanodevices of ZnO nanorod(NR)arrays and nanotetrapods(NTPs).Recent work done by the authors are also presented.After a brief introduction to the controlled fabrication methods for the highly-ordered ZnO NR arrays and NTPs,we present some aspects of the fundamental properties,especially optical performance,of ZnO NRs/NTPs.Then,we provide an overview of the applications to functional nanodevices based on individual NR and NTP of ZnO.It is demonstrated that different morphologies of ZnO nanostructures have salient effects on their properties and applications.Although much progress has been achieved in the fundamental and applied investigations of ZnO NRs/NTPs over the past decade,many obstacles still remain,hampering further development in this field.Finally,some longstanding problems that warrant further investigation are addressed.
Through floating catalyst chemical vapour deposition（CVD） method, well-aligned isolated single-walled carbon nanotubes （SWCNTs） and their bundles were deposited on the metal electrodes patterned on the SiO2/Si surface under ac electric fields at relatively low temperature（280℃）. It was indicated that SWCNTs were effectively aligned under ac electric fields after they had just grown in the furnace. The time for a SWCNT to be aligned in the electric field and the effect of gas flow were estimated. Polarized Raman scattering was performed to characterize the aligned structure of SWCNTs. This method would be very useful for the controlled fabrication and preparation of SWCNTs in practical applications.
Arrays of noble metal nanoparticles show potential applications in （bio-）sensing, optical storage, surface-enhanced spectroscopy, and waveguides. For all such potential devices, controlling the size, morphology, and interparticle spacing of the nanoparticles is very important. Here, we combine seed-mediated growth with nanosphere lithography to study the controllable growth of gold nanoparticles （Au NPs）, in which the self-assembly monolayer of polystyrene （PS） on a silicon surface is used to guide the modification of allaunesilanes and the subsequent adsorption of gold seeds; seed-mediated growth is applied to controlling the morphology and size of Au NPs. The size of adsorption region （determining the number of adsorbed gold seeds） is controlled by etching PS microspheres with oxygen plasma or annealing PS microspheres at the glass transition temperature. The size and morphology of the Au NPs are controlled by changing growth conditions. In such a way, we have achieved the dual control of the obtained Au NPs. Preliminary results show that this strategy holds a great promise. This approach can also be extended to a wide range of materials and substrates.
