Dispersiveness Effect of Multi-walled Carbon Nanotube(MWNT) on the I-V Characteristic of MWNT Reinforced Cement Material

The dispersion impacts of Polyacrylic acid(PAA) or/and Triton x100(Tx100) on different concentrations of multi-walled carbon nanotube(MWNT) were investigated by naked observation,hereafter five groups MWNT reinforced cement materials(MWNT/CMs) were mix cast.The I-V characteristics of MWNT/CMs were investigated by four-electrode technique,and then the dispersiveness effects of MWNT amongst three groups MWNT/CMs were observed by SEM.Results show that it is hard to achieve good dispersion of MWNT with single PAA dispersion,esp.when MWNT with high concentration.MWNT with tangled and aggregated has bad distribution within the correspondent MWNT/CM,and there exist high resistivities(ρ) and the marked nonlinearity of the I-V characteristic.But,the blackness homogeneity of MWNT dispersed solution with high concentration could still retain above 5 d with PAA Tx100(Ф(PAA)∶Ф(Tx100)=2) surfactants,microstructure reveals that most of MWNT has good distribution and compatible within matrix,and the ρ of NPT4 group MWNT/CM is only around 12.7 Ω·m(the maximum is only 14.8 Ω·m),as comparison,the ρ of NPT4 group MWNT/CM with the same MWNT loading is 429.8 Ω·m,and the maximum arrives to 1170.1 Ω·m,respectively.