Here we present a useful ammonia (NH₃) gas sensor based on reduced graphene oxide (RGO)–polyaniline (PANI) hybrids. PANI nanoparticles were successfully anchored on the surface of RGO sheets by using RGO–MnO₂ hybrids as both of the templates and oxidants for aniline monomer during the process of polymerization. The resultant RGO–PANI hybrids were characterized by transmittance electron microscopy, infrared spectroscopy, Raman spectroscopy, UV-Vis spectroscopy, and scanning electron microscopy. The NH₃ gas sensing performance of the hybrids was also investigated and compared with those of the sensors based on bare PANI nanofibers and bare RGO sheets. It was revealed that the synergetic behavior between both of the candidates allowed excellent sensitivity and selectivity to NH₃ gas. The RGO–PANI hybrid device exhibited much better (3.4 and 10.4 times, respectively, with the concentration of NH₃ gas at 50 ppm) response to NH₃ gas than those of the bare PANI nanofiber sensor and bare graphene device. The combination of the RGO sheets and PANI nanoparticles facilitated the enhancement of the sensing properties of the final hybrids, and pave a new avenue for the application of RGO–PANI hybrids in the gas sensing field.

Polymer nanocomposites show unique properties combining the advantages of the inorganic nanofillers and the organic polymers. The mesoporous silica nanofillers have received much attention due to their ordered structure, high surface area and ease for functionalization of the nanopores. To accommodate macromolecules, the nanopores lead to unusually intimate interactions between the polymer and the inorganic phase, and some unusual properties can be observed, when compared with nonporous fillers. Whereas many review articles have been devoted to polymer/nonporous nanofiller nanocomposites, few review articles focus on polymer/mesoporous silica nanocomposites. This review summarizes the recent development in the methods for synthesizing polymer/mesoporous silica nanocomposites based on the papers published from 1998 to 2009, and some unique properties of these composites are also described.

A novel hybrid material composed of single-walled carbon nanotubes (SWNTs) and cobalt phthalocyanine (CoPc) derivatives have been obtained. The resultant hybrid has been confirmed by infrared spectroscopy, Raman spectroscopy, UV-Vis spectroscopy and X-ray photoelectron spectrometry. The results revealed that the CoPc derivatives had been successfully anchored on the surface of nanotubes through π–π stacking. The quantitatively determination of the CoPc derivatives have also been carried out through characterization by thermogravimetric analysis. Furthermore, the morphology of the resultant SWNT-CoPc derivative hybrids has been observed by transmission electron microscopy and scanning electron microscopy. Finally, gas sensor tests were performed to check the potential of this hybrid material while the sensing devices have been fabricated. The synergetic behavior between both of the candidates allows an excellent sensitivity and selectivity to dimethyl methylphosphonate (DMMP) (stimulant of nerve agent sarin). Overall, we present the advantages of combining metallophthalocyanine (MPc) with SWNTs in enhancing the properties of the final product, and pave a new avenue for the application of SWNT-MPc hybrids in the gas sensing field.