Effects of dispersible graphene in water on the electrical conductivity, heat generation and thermoelectric properties of cement slurry

In order to solve the problem that graphene (G) is uniformly dispersed in cement slurry and its dosage is too high when it is functionalized into cement-based materials, a graphene (G-SD) with both high conductivity and water solubility was selected as a conductive filler. The effect of sodium lignosulfonate (MN) on the dispersion ability of G-SD in saturated calcium hydroxide solution (CH) used for simulated cement pore solution in the presence of polycarboxylate superplasticizer (PCE) and the effects of G-SD on the resistivity, electrothermal properties, snow melting and deciding, and thermoelectric properties of cement paste were investigated. The absorbance test shows that when the mass ratio of MN to G-SD is 3∶1, the dispersion of G-SD reaches the best. The electrical performance test shows that percolation threshold of graphene cement-based materials is 0.4%. What's more, good electrothermal performance are shown under the threshold, the temperature of cement paste specimen can be increased by 320℃ for 20 min with 30 V voltage, and 4 cm thick ice layer can be basically melted within25 min, so it possesses good potential for deicing and snow-melting. The thermoelectric properties shows that Seebeck coefficient of cement paste specimen is 154.4 μV/K when the content of G-SD is 0.1% by the cement mass. The above studies show that G-SD can endow cement-based materials with excellent electrical, thermal and thermoelectric functional properties at very low dosage.