Search

Magnesium oxychloride (MOC) cement as viable substrate candidate has unique applications in a range of functional and novel sensing applications due to their low thermal conductivity, high toughness, durability and excellent fire resistance. Here, we developed a facile strategy to fabricate metallized patterns on MOC cement composites through laser-induced selective metallization. The laser sensitiser of copper hydroxyl phosphate [Cu2(OH)PO4] was incorporated into MOC cement to prepare MOC cement composites. Then, the metallized copper patterns were obtained on MOC cement composites after 1064 nm pulsed laser activation and electroless copper plating (ECP). The obtained copper layer on MOC cement composites exhibited high electrical conductivity and excellent mechanical adhesion to the substrate. Furthermore, the rough copper patterns exhibited self-cleaning ability after superhydrophobic modification, which could prevent the surface from being contaminated. The metallized copper pattern could rapidly heat up when energised due to the Joule heating effect, and it can be applied for electric heating and automatic deicing in winter. In addition, a UV photodetector was fabricated by designing an interdigital metallized pattern combined with the UV light response characteristics of nano-ZnO, which has potential application on intelligent functional devices.

The need to improve the understanding of the properties of cement-based materials calls for the development of tools for visualizing and quantifying chemical reactions and flows of fluids within them. In this paper, we report the results of an experimental study where a sample of fractured cement-paste was subjected to injection of fluids (krypton, CO 2 and water) and imaged simultaneously by X-ray computed tomography (CT). Initial porosity of the sample was estimated using a subtraction method based on CT scans taken initially and during krypton injection. The CT reconstructions were segmented to visualize crack patterns and fluid flow in three-dimensions and to quantify the evolution of porosity during the experiment. The results show that CT captures the formation of a carbonate phase in the sample during CO 2 injection, and the flow of water in the fractured media. We quantify the reduction of porosity resulting from the carbonation reaction. We observe that the newly formed carbonated layer impedes water flow and, locally, can lead to crack healing. The results demonstrate the ability of CT to image reactive transport in cement-based materials, and support the feasibility of this imaging tool for their characterization.