Solid-state high-resolution 29Si NMR spectroscopy of synthetic 14 Å, 11 Å and 9 Å tobermorites

Microstructure Changes in Autoclaved Aerated Concrete during Carbonation under Working and Accelerated Conditions

“…Chemical shifts of 29 Si MAS NMR are shown in Table 2. Q 2 and Q 3 spectrum of Nontreated-AAC corresponding to the silicate double-chain structures of Tobermorite-1.1nm were found to be in agreement with Wieker et al (1982). The other peaks of Q 2 and Q 3 of the Field-and Labo-AAC approximately at -83 ppm and -103 ppm, which corresponds to the protonated silicate ions, were found with an increase of Dc (Klur et.…”

Hydrothermal synthesis and characterization of aluminium and sulfate substituted 1.1nm tobermorites

“…It has a layer-type structure and is prepared using reactive Ca and Si starting materials under hydrothermal conditions below 180 • C. In recent years, the research on tobermorite reached an epic. Some researchers tried to understand its structure [1,2] and others tried to optimize its formation from pure raw materials [3][4][5][6] or industrial by-products [7][8][9][10][11]. The last trend was motivated not only by the importance of tobermorite as autoclaved building materials, but also by other advances applications.…”

“…To facilitate the description of the silicate structure, researchers [2,19] use Q 0 -Q 4 notation, which refer to the connectivity. Where the superscript denotes the number of other Q units to which it is bonded.…”

Preparation and evaluation of a mesoporous calcium-silicate material (MCSM) from coal fly ash for removal of Co(II) from wastewater

“…Table 1 Chemical composition of the raw fly ash (wt%) and the desilicated liquor (g L À1 ). The NMR spectrum was recorded on a solid-state Advance 300 CP-MAS 29 Si NMR (Bruker, Germany), and the assignment of 29 Si chemical shifts was done according to Wieker et al [28].…”