Hydrothermal synthesis of an expanded perlite based lightweight composite for indoor humidity regulating

Direct Synthesis of Eco-friendly Construction Material from Low-quality Sand via Sol-gel Method

“…The introduction of Al makes the tetrahedral structure negatively charged and the embedded K + can balance the charge. [41] The newly formed tetrahedral structure with the embedded K + is likely to be microcline. During this reaction process, the raw sand sharply decreases with the formation of microcline and potassium hydrogen silicate, which can make the whole structure more homogeneous and lower the porosity.…”

“…O-H (H2O, Si-OH) [36,37] 2921, 2852 C-H (TEOS) [36,37] 1639 -OH (H2O) [40,41] 1384 C-H (TEOS) [36,37] 1084 Si-O-Si (quartz, TEOS) [34,40] 1133 Si-O-C(TEOS), Si-O-Si (microcline or potassium hydrogen silicate) [36,37,42] 1008 Al-O-Si (Al) (kaolinite and microcline or potassium hydrogen silicate) [33,42,43] 880 C-H (TEOS), Si-O-Si (Al) (microcline or potassium hydrogen silicate) [37,39,44] 775 O-Si-O (TEOS), Si-O-Si (quartz) [34,40] 692 Si-O-Si (Al) (quartz, kaolinite) [33,34,35] 619 Si-O-Si (microcline) [39] 529 Si-O-Al (kaolinite) [33,34,45] 466 O-Si-O (kaolinite, TEOS) [33,34,35]…”