Temperature-Driven Structural Evolution during Preparation of MCM−41 Mesoporous Silica

Autor: Tao Xu, Kuixin Cui, Shengming Jin
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Materials, Vol 17, Iss 8, p 1711 (2024)
Druh dokumentu: article
ISSN: 1996-1944
DOI: 10.3390/ma17081711
Popis: This study explores the influence of micelles on the evolution of MCM−41’s pore structure via 24 h hydrothermal treatments in a range of temperatures from 100 °C to 200 °C. MCM−41 was characterized using BET, SAXD, FTIR, TEM, and TG-DSC. The findings demonstrate that with temperature elevation from 100 °C to 160 °C, the micelles undergo expansion, leading to an enhanced lattice constant from 4.50 nm to 4.96 nm and an increase in pore diameter from 3.17 nm to 3.45 nm, while maintaining the structural orderliness of the pore channels. Upon cooling, the reversible contraction of micelles and the strategic addition of water glass contribute to a reduction in pore size. However, at a threshold of 180 °C, the SAXD (100) peak’s half-peak width surges by approximately 40% relative to that at 160 °C, illustrating a progressive disruption of the hexagonal configuration of MCM−41. Coupled with elevated silica dissolution at higher temperatures in an alkaline solution, a total disintegration of the ordered pore structure at 200 °C results in a drastic reduction in the specific surface area to 307 m2/g. These results are beneficial to developing structural transformation mechanisms of MCM−41 materials and designing mesoporous materials via temperature modulation innovatively.
Databáze: Directory of Open Access Journals
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