Cement-based composite with humidity adsorption and formaldehyde removal functions as an indoor wall material. (30th June 2020)

• Record Type: Journal Article
• Authors: Ren, Qiang; Zeng, Zhiyong; Xie, Mingjun; Jiang, Zhengwu
• Is Part Of: Construction & building materials. Volume 247(2020)
• Publication Date: 2020-06-30
• Subjects: Cement -- Ag/TiO2-BC -- Diatomite -- Humidity adsorption -- Formaldehyde removal; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2020.118610
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Multifunctional cement-based composite for indoor wall was produced. Humidity adsorption capability is significantly due to Ag/TiO2 -BC addition. Formaldehyde can be efficiently removed due to Ag/TiO2 -BC addition. Abstract: Indoor air environment is of great significance for the comfort and health of residents while humidity adjustment and air purification are essential to provide favorable air environment. This paper aims to prepare multifunctional cement-based composite with both humidity adsorption and formaldehyde removal properties for indoor walls. Bamboo charcoal loading silver doped titanium dioxide (Ag/TiO2 -BC) was synthesized and used in cement-based paste. Properties of the prepared paste including flowability, bonding strength, humidity adsorption and formaldehyde removal ratio, were investigated. Results show that Ag/TiO2 -BC increases superplasticizer demand to keep the mini slump spread at a desirable level due to the higher specific surface area and porous structure of Ag/TiO2 -BC. Besides, sample with higher content of Ag/TiO2 -BC has lower bonding strength whereas the limit value of 0.5 MPa can be met if cement content is not lower than 30%. Humidity adsorption result indicates that Ag/TiO2 -BC significantly improves the humidity content of mixture, which shows an approximately linear trend with Ag/TiO2 -BC content. Cement paste with Ag/TiO2 -BC has 226.5% higher humidity adsorption capacity compared to that with diatomite, which is the result of combined effects of specific surface area and effective pore volume. Formaldehyde removal result shows that formaldehyde removal ratio increases as Ag/TiO2 -BC content rises and equilibrium removal ratio can be reached at 24 h. The removal of formaldehyde by cement with diatomite is due to the adsorption of diatomite while cement with Ag/TiO2 -BC has both adsorption and photocatalytic decomposition effects. These findings demonstrate that cement-based composite with favorable humidity adsorption and formaldehyde removal performance as well as traditional properties can be prepared by incorporating Ag/TiO2 -BC, showing a high potential to be used as wall materials to enhance indoor air environment.