Infrared Emission Spectroscopic Study of the Dehydroxylation via Surface Silanol Groups of Synthetic and Natural Beidellite

Modification of Chrysotile Surface by Organosilanes: An IR–Photoacoustic Spectroscopy Study

“…Normally occurring silanol (Si-OH) on crystal edges and aluminol (Al-OH) groups in the octahedral sheets as well as heatinduced silanol groups have been detected in some synthetic or natural aluminosilicates (5). Besides the structural hydroxyl groups, water plays also an important role in the incorporation of certain organic species in clay minerals (6,7).…”

Catalytic pyrolysis of polyethylene: A comparison between pillared and restructured clays

“…The clays chosen for the present study were three types of smectites: (i) montmorillonite, a mineral with mainly Mg 2+ substituting for Al 3+ in its octahedral layer; (ii) saponite, a mineral with mainly Al 3+ substituting for Si 4+ in its tetrahedral layer, and (iii) beidellite, a mineral classified as a dioctahedral Al-smectite, where Si 4+ has been replaced by Al 3+ and which possess a very good acidic behaviour (stronger acidity than montmorillonite) in catalytic reactions [20]. These differences in structural composition give the Al and Fe/Al-pillared forms different acidic [21] and catalytic behaviour [22].…”

Theoretical study on the influence of the Mg2+ and Al3+ octahedral cations on the vibrational spectra of the hydroxy groups of dioctahedral 2:1 phyllosilicate models

“…The ν(AlOHAl) modes appear at 3,606 and 3,604 cm −1 (Table 2), where the first corresponds to the symmetric normal mode. The experimental wavelengths [57] appear at higher frequencies than these calculated values ( Table 2). In general, this could be due to the high Mg content, which produces highly charged tetrahedral oxygens, increasing the interactions with the OH group and resulting in a decreased ν(OH) frequency.…”

“…a Experimental data of ferrouginous smectite[15] b Experimental data of beidellite[57] c From Illite-smectites[16] d Experimental data[11] e Experimental data[4] f From Pelletier et al[20] g From Farmer and Russel[58] h From computational results of cluster models[25] i From previous calculations of smectites with different composition[10] j Experimental data[59,60] k From experimental data[61] 2402, Page 6 of 10 J Mol Model (2014) 20:2402…”