Silicon rubber (SR) filled with carbon black (CB) and carbon black (CB)/graphene nanoplatelets (GNPs) hybrid fillers are synthesized via a liquid mixing method. The effects of filler type on the electrical properties and piezoresistive properties (near the region of the percolation) of the conductive SR composites are studied. It is suggested that the conductivity of the composite filled with CB/GNPs hybrid fillers in the mass ratio of 2 : 4 is much higher than that in other ratio. Percolation threshold for CB/GNPs/SR is found to be 0.18 volume fractions lower than CB/SR. Moreover, force rang and linearity of GNPs/CB/SR is higher than CB alone filling system. And the repeatability of the GNPs/CB/SR composites is better than CB/SR. Not repetitive index (ez) of them is 0.1 and 0.18, respectively. The results suggest that the GNPs/CB/SR composites provide a new route toward fabrication of flexible piezoresistive sensors with high performance. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39778.

Abstract

Functionalized multi-wall carbon nanotubes (MWCNTs) treated by mixed acids have been used to develop a capacitive humidity sensor based on MWCNTs/silicone rubber (SR) composite film. The MWCNTs/SR composites were prepared through conventional solution processed method. The micrographs of MWCNTs/SR composites were observed by transmission electron microscopy (TEM) and scanning electron microscope. The FT-IR spectra demonstrated the successfully grafting of AOH groups on the treated MWCNTs. The sensing properties of the composite at different relative humidity (RH) and frequency were characterized and linear sensing responses of the MWCNTs/SR composites to RH were observed. The treated MWCNTs/SR composite film (Tr-film) had higher sensitivity than that of the untreated MWCNTs/SR composite film (Un-film). Experimental data indicate that the Tr-film exhibits an excellent long-term stability, small hysteresis, and fine reproducibility. The response and recovery time of the Tr-film were 30 and 27 s, respectively. Thereby, such Tr-film had potential applications as humidity sensors. V C 2014 Wiley Periodicals, Inc. J. Appl.Polym. Sci. 2014, 131, 40342.

The welding titanium cathode roller has the obvious advantages of low cost, high efficiency, and no diameter restriction. Unfortunately, the longitudinal weld on the cathode roller adversely impacts the quality of the electrolytic copper foil due to the great difference between the microstructure of the weld zone and the base metal. Thus, it is crucial to reduce their difference by regulating the microstructure of the weld zone. In this study, a novel complex treatment of heat treatment and sandblasting is primarily developed for regulating the microstructure of the weld zone. The results show that the novel complex treatment has an efficient effect on regulating the microstructure of the weld zone and making the microstructure in the weld zone close to that of the base metal. During vacuum annealing, the microstructure of the weld zone is refined to some degree, and 650 °C annealing has the optimal effect, which can effectively reduce the ratio of α phase’s length to width and reduce the microstructure difference between the weld zone and the base metal. At the same time, with an increase in the annealing temperature, the tensile strength and yield strength decreased by about 10 MPa; the elongation after fracture increased by 20%; the average microhardness of the WZ and the HAZ decreased by about 10 HV0.10; and that of the BM decreased by about 3 HV0.10. The heat treatment after welding can effectively adjust the properties of the weld zone, reduce the hardness and strength, and improve the toughness. The subsequent sandblasting after annealing can further refine the grain size in the weld zone and make the microstructure in the weld zone close to that of the base metal. Sandblasting after annealing can further refine the grain in the weld zone and make the microstructure in the weld zone close to that of base metal. Meanwhile, an application test confirmed that the adverse impact of a longitudinal weld on the quality of electrolytic copper foil could be resolved by adopting this novel complex treatment. Therefore, this study provides valuable technical support for the “welding” manufacturing of the titanium sleeves of the cathode roller.