Renjia Zhou

Solvent-dependent fluorescence property of multi-walled carbon nanotubes noncovalently functionalized by pyrene-derivatized polymer

Multi-walled carbon nanotubes (MWCNTs) were supramolecularly functionalized by pyrene-derivatized hydrolyzed poly(styrene-co-maleic anhydride) (pyrene-HSMA) in aqueous solution. The MWCNTs/pyrene-HSMA conjugates were found to exhibit a solvent-dependent fluorescence property by photoluminescence measurements. The fluorescence intensity of the MWCNTs/pyrene-HSMA conjugate was used as a probe to estimate the interaction between polymer and MWCNTs in solvents. The polymer conformation around the MWCNTs was demonstrated by atomic force microscopy. We suggested that pyrene-HSMA functionalized MWCNTs in a non-wrapping mode, and that the conformation change of the polymer around the MWCNTs resulted in the solvent-dependent fluorescence property. The dispersion state of the MWCNTs/pyrene-HSMA conjugate in various solvents was also investigated by transmission electron microscopy. The fluorescence responses of the MWCNTs/pyrene-HSMA conjugate to pH value and temperature were studied as well.

A green route to water soluble carbon nanotubes and in situ loading of silver nanoparticles

A green approach has been developed to synthesize water soluble multi-walled carbon nanotubes (MWNTs). Ag nanoparticles have been loaded on the as-synthesized MWNTs via the in situ solution method. The strategy is based on the introduction of hydroxyl and carboxyl groups through a mild modification of MWNTs via polycondensation of citric acid and D-sorbitol, improving the water solubility of MWNTs, giving rise to preferred sites of Ag nucleation, and providing mild in situ reducing agents. The modification of MWNTs and loading of Ag nanoparticles on MWNTs were demonstrated by Fourier transform infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy, and scanning electron microscopy.

A facile route to synthesize three-dimensional CdS nanocrystals

Synthesis of nanoscale inorganic crystals with controlled size, shape, and hierarchy has attracted intensive research interest, since they are potential building blocks for advanced materials and optoelectronic devices. As an important group II-IV semiconductor with extensive applications in optical and electronic nanodevices, complex three-dimensional nanocrystals CdS with well-defined structures have just received great attentions since they offer new opportunities as building blocks to fabricate or assemble into advanced materials for further generation of optoelectronic devices, we report for the first time to large-scale synthesize an interesting 3D structured CdS nanocrystals by a facile hydrothermal method. The photoluminescence results of the 3D CdS nanocrystal indicated they have the potential applications for the building blocks on optoelectronic devices.

In-situ fabrication of highly-fluorescent nanohybrids based on Carbon Nanotubes and Gold Nanoparticles

Highly-fluorescent, water-soluble and ambient-stable nanohybrids based on multi-walled carbon nanotubes and gold nanoparticles (Au@MWNTs) with high-density and well-distributed Au nanoparticles were obtained assisted by organic optoelectronic active molecules as an interlinker and stabilizer via a facile in-situ fabrication method in aqueous solution, and were confirmed by TEM, SEM, EDX, UV-Vis measurements. The Au nanoparticle diameters of the hybrids can be controlled and decreased to a limited small range with high stability via this in-situ fabrication approach. The optical properties of the hybrids were studied, and it was found that the hybrid exhibited strong visible luminescence under the UV lamp irradiation, which might extend its potential application on light emitting sources, biological labeling etc.