Layered silicate by proton exchange and swelling of AMH-3

Amine‐Tethered Solid Adsorbents Coupling High Adsorption Capacity and Regenerability for CO2 Capture From Ambient Air

“…Absorption bands related to the silica framework were observed at around 1100 cm À1 and 800 cm À1 , corresponding to the asymmetric and symmetric stretching vibrations of SiÀOÀSi bonds, respectively. [32][33] On the other hand, a peak at around 600 cm…”

“…[31][32][33] The adsorption bands between 4000 and 3000 cm À1 can provide information on the stretching vibrations of different types of hydroxyl groups, such as isolated, geminal, or associated hydroxyls, forming hydrogen bonds. [33][34] In the PEI/silica adsorbent, the silanol peaks were broadened and shifted to a lower frequency compared to the sharp peak associated with isolated silanols observed in pure silica (> 3700 cm À1 ), possibly because of hydrogen bonding effects of water or polymer physisorbed in the PEI/silica material. In addition, the presence of hydrogen bonding between the amine groups of PEI and the surface hydroxyls appeared to diminish the NÀH stretching vibrations in the range of 3500 to 3300 cm À1 to the point that they were barely noticeable in the PEI/silica material.…”

Current Status and Future Prospect of Polymer‐Layered Silicate Mixed‐Matrix Membranes for CO2/CH4 Separation

“…In a study, Choi introduced an innovative method, i.e., by sequential intercalation of dodecyl amine after proton exchange in the presence of amino acids, for the swelling of AMH‐3 because the routine methods used for swelling of clays are not applicable for AMH‐3 due to its strong interlayer bonding 55. Also, conventional methods of dispersion and sonication do not guarantee exfoliation of AMH‐3 in a polymer matrix.…”

Large Single Crystals of Heterosubstituted Titanosilicate JDF‐L1 Grown Orthogonally in a Regular Levo‐Spiral Mode

“…The unnoticeable spectral peaks that split up at δ = 90.8 and 91.7 ppm might be analogously assigned to Si(2Si,1Ti,1Fe) in Fe‐JDF‐L1, considering the magnetic effect of Fe 3+ ions. As evidenced by the weak reflection at approximately 26.2°(2 θ ) in Figure , the shoulder peak at δ = –115.8 ppm for lamellar JDF‐L1 implies the presence of the appreciable impurity originating from the condensation of silica tetrahedra, which was also proved to occur in layered JDF‐L1 . The secondary 29 Si chemical shifts at –61.0 and –61.2 ppm, for Al‐JDF‐L1 and Fe‐JDF‐L1, respectively, are indicative of the local disorder of Si species within heterosubstituted JDF‐L1 or noncrystalline metalosilicates (i.e.…”