|Assignments of the main silica bands in the 700- to 4,000 cm−1 region|
|Band maximum (KBr powder, cm−1)||Assignmenta||Reference|
|3,745||ν (isolated silanol groups) Si-OH||[38,40]|
|3,700 to 3,000||ν hydrogen-bonded silanols (overlapping of the stretching modes in hydrogen-bonded hydroxyl bands produced by O-H bonds in adsorbed water and Si-OH)||[38,40]|
|1,867 and 1,980||Si-O-Si stretching modes||[38,40]|
|Approximately 1,628 to 1,630||Proton-containing components σOH (silanol groups and the deformation vibrations of the O-H groups in physically adsorbed molecular water at the silica surface)||[37-39]|
|Approximately 1,083||Si-O-Si stretching||[38,40]|
|1,000 to 1,300||νas, anti-symmetric stretching of Si-O-Si bonds|||
|932 to 939||Si-OH stretching||[38,40]|
|Approximately 809||Bending vibration of Si-O-Si bonds||[38,40]|
|Approximately 790||Bending modes in Si-OH bonds||[38,40]|
aνas/s, asymmetric/symmetric stretching mode.
Azizova et al.
Azizova et al. Nanoscale Research Letters 2014 9:234 doi:10.1186/1556-276X-9-234