The role of electronic and ionic conduction in the electrical conductivity of carbon fiber reinforced cement

Self-Compacted Concrete with Self-Protection and Self-Sensing Functionality for Energy Infrastructures

“…However, the reinforcement of the cement matrix at the microscale with the CMF has contributed to compensate for the negative effect of the aggregates and has favored the flow of current through cement paste, probably with a mixed mechanism for electrical conduction. The water-filled pores are relevant for electrical conduction in the cement paste as tested in [19,22] and the mix of CNT and CMF will favorand contribute to conduction by contacting and tunnelling as predicted in [29][30][31]. In this work, the lack of liquid in the pores at 105 • C has caused a significant increase in electrical resistivity, shown in Figure 7.…”

“…Electrical conduction in a cementitious material takes place, first, through the liquid water in the pores, that is, the mobility of ions in the pore solution. This type of conductivity is identified as the ionic conductivity [29] of a cementitious material and is significantly affected by the moisture content in pores [19]. Well-distributedself-sensing additives in the cement paste matrix improves the conductive electrical network of the cementitious material.…”

“…However, the electrical conduction mechanism of self-sensing cementitious materials is complex and not well understood. The most plausible governing conduction mechanism is identified as beingelectronic (due to the direct contact between the functional additives) and helped by a tunnelling mechanism (conduction occurring between close functional additives which are not in contact) [16,[29][30][31]. Nevertheless, the combined contribution of all the conduction systems: Ionic+contacting+tunnelling for electrical conductivity enhancement of cementitious materials with self-sensing additives is the most probable.…”

Photoactivity of titanium dioxide/carbon felt composites prepared with the assistance of supercritical carbon dioxide: Effects of calcination temperature and supercritical conditions

“…Thus, the strong interaction between TiO 2 and the porous matrix in the composites is a prerequisite for enhanced reactivity [19,22]. It is known that the small fibers of the CF exhibit better electronic conductivity than glass fibers [23,24]. The good electronic conductivity of the carbon fibers, as well as the intimate contact between TiO 2 and the carbon fibers, facilitates rapid migration of the photoexcited electrons from the conduction band of TiO 2 to the CF support, which reduces the rate of recombination between electrons and holes and leaves more holes to participate in the oxidization of dye molecules.…”

Surface modification and submicron structure of carbon fibers through high current pulse

“…This is mainly because of their superior mechanical properties (high specific strength modulus, and low expansion coefficient), low density, good environmental compatibility, longterm durability and high resistance to chemical corrosion [2,[6][7][8][9]. However, in high current pulsed discharge, the behavior of carbon fibers as electrically exploded conductor is not understood.…”