Characteristics analysis of self-luminescent cement-based composite materials with self-cleaning effect

Abstract

In this study, self-luminescent cement-based composite materials (SCCM) were prepared by doping luminescent powder and reflective powder into cement-based materials, and then self-luminescent and self-cleaning cement-based composite materials (SSCCM) were obtained by hydrophobic treatment on the surface of the SCCM, afterwards their mechanical properties, luminous properties, hydrophobicity and mechanism were evaluated. The results indicated that doping luminescent powder and reflective powder could enhance the brightness and afterglow time of the SCCM specimen. Compared with the control group, the initial and 10 min brightness increased by 4.7–45.79% and 14.63–59.09%, respectively. The 8 h luminous brightness was in range of 0.02–0.2 cd/m2. The addition of luminescent powder and reflective powder improved the mechanical strength of the SCCM specimen, while the super-hydrophobic materials had little effect on its strength and luminous properties. The luminescent powder and reflective powder not only reacted with cement hydration products to produce a large number of hexagonal plates CH and cluster AFm crystal, but also promoted the hydration reaction of the un-hydrated cement particles. Moreover, due to its smaller particle size, it could fill the tiny pores among hydration products, thereby improved the micro-distribution of the hardened cement matrix and enhanced the strength. The hydration products of cement could absorb short wave ultraviolet light, thus reducing the excitation wavelength range and intensity of the specimen, the emission spectrum was yellowish green with a peak value of 520 nm. The SSCCM had excellent hydrophobicity, the contact angle and surface energy of the specimen coated with fluorosilane materials is 159.8° and −19.11 mJ/m2, respectively. Due to the fluorination, the surface roughness of the SSCCM was larger, where exists a large number of hierarchical micro- and nano-structure.