Basic Principles of Nano-Engineered Cementitious Composites

Electromagnetic wave shielding/absorption performances of cementitious composites incorporating carbon nanotube metamaterial with helical chirality

“…This is also verified by Han et al. 25 that dielectric permittivity will decrease when fillers' content is higher than percolation threshold. From Figure 9(c), (d) and (f), magnetic polarization degree, wave loss and magnetic loss tangent under magnetic field of all groups are almost same, illustrating HCNTs will not produce magnetic loss.…”

Development of Photocatalytic 3D-Printed Cementitious Mortars: Influence of the Curing, Spraying Time Gaps and TiO2 Coating Rates

“…Titanium dioxide (TiO 2 ) holds particular features, such as high chemical stability, high oxidation-reduction capacity, non-toxicity, and is available at a lower price, besides being the most employed semiconductor in photocatalytic materials [2,3,8,[12][13][14][15][16][17]. TiO 2 is widely used in different fields for the purpose of water and air purification and self-cleaning [2,[18][19][20][21], including in civil engineering for cementitious materials (by, e.g., [3][4][5]7,17,[22][23][24][25]). The main factors that allow the cementitious materials an ideal support medium for semiconductors (and in particular TiO 2 ) are: (i) the porous structure of the cementitious mortar/concrete bulk [4,9,24]; (ii) the strong binding ability of the cementitious materials [9,17]; as well as (iii) the compatibility between TiO 2 particles with the alkaline nature of cementitious materials [6,9].…”

“…Different methodologies have been used to apply semiconductors into cementitious composites, in order to endow them photocatalytic properties [24]. Volume incorporation during the mixing process (by, e.g., [3,5,22,23]), binder modification [4,15], using the catalytic carrier in the cementitious mixture [24,25], and surface coating by spraying semiconductor particles (by, e.g., [3,5,17,24,26,27]) are some methods used for the photocatalytic functionalization. The coating method by spraying semiconductor particles is recognized as the most efficient and easiest application method for using semiconductors compared to other approaches [17,24].…”

“…In the case of adding semiconductors into the mixture composition, it is reported that higher amounts of semiconductors must be used to have the same distribution of TiO 2 particles on the specimens' surface when compared to the surface coating method [5]. On the other hand, using higher amounts of TiO 2 can influence the matrices' rheological (in the fresh state) and mechanical properties [4,5,16,25]. A detailed description of the influence of TiO 2 semiconductors on the properties of cementitious composites can be found elsewhere [16,25].…”

“…On the other hand, using higher amounts of TiO 2 can influence the matrices' rheological (in the fresh state) and mechanical properties [4,5,16,25]. A detailed description of the influence of TiO 2 semiconductors on the properties of cementitious composites can be found elsewhere [16,25].…”