Synthesis and characterization of a mesoporous Al-MCM-41 Molecular Sieve Material and its Moisture Regulation Performance in Water Molecule Adsorption/Desorption

Abstract

In this study, liquid crystal display waste glass (LCD wg ) and chemical mechanical polishing sludge (CMP s ) were investigated as alternative sources of SiO 2 and Al 2 O 3 for the preparation of the mesoporous moisture regulation material Al-MCM-41 (MRMCM). The aluminosilicate supernatant from the alkali fusion of LCD wg and CMP s and the surfactant cationic cetyltrimethylammonium bromide (CTAB) were used as structure-directing agents. Synthesis was carried out by alkali fusion and hydrothermal methods, and the factor affecting the synthesis was the alkali fusion liquid-solid ratio. Reliable instruments and methods, including XRD, TEM, XRF, BET and BJH, were employed for characterization of the fabricated MRMCM. The results show that the pore size of these materials was between 3.0 and 4.5 nm, and with an increase in the liquid-solid ratio, the specific surface area of MRMCM increased to a maximum value of 1260 m 2 /g and exhibited a mesoporous structure. In addition, the hydrothermal temperature and the specific surface area also had a significant positive correlation as the temperature increased such that the surface area increased from 370 m 2 /g to 601 m 2 /g, which is a significant increase of 1.62 times. MRMCM exhibited a positive linear correlation between pore volume and specific surface area during 48 h of moisture absorption and desorption, and the amount of moisture absorbed by mesoporous MRMCM was determined. Thus, the mesoporous molecular sieves met Japan Industrial Standard JIS A 1470–1 2002, which regulates moisture regulation building materials (response to humidity variation > 29 g/m 2 ). Therefore, the materials can be utilized in multiple applications, particularly as moisture regulation materials in building engineering. • A new type of Al-MCM-41 mesoporous humidity control material is reported. • The influence of the liquid-solid ratio and hydrothermal temperature are discussed. • High adsorption/desorption capacity of water molecule were observed. • The mesoporous molecular sieves met Japan Industrial Standard JIS A 1470.