Different low-cost materials to prevent the alteration induced by formic acid on unstable glasses

Heritage Science

Table 3 Allocation of glass FTIR-ATR bands identified in Fig. 8

Wavenumber (cm⁻¹)	Assignment	References
3300	ν (OH) stretching (water and silanol)	[39,40,41]
2820	ν (CH) stretching (formate)	[39, 42]
2730	δ (CH) bending vibration (formate)	[42]
2160	δ (H–O–H) bend + libration (water)	[43]
1630	δ (H–O–H) scissors bending (water)	[44]
1580	ν (COO⁻) of Na stretching asymmetric (formate)	[39, 42, 45]
1380	ρ (COO⁻) rocking (formate)	[39, 45]
1350	ν (COO⁻) of Na stretching symmetric (formate)	[39, 42, 45]
1100	ν (Si–O–Si) stretching asymmetric (glass)	[46, 47]
1080	ρ (COO⁻) rocking (formate)	[39, 48]
1020	ν (Si–O–Na) stretching (glass)	[47, 49]
890	ν (Si–OH) stretching (glass)	[46, 47]
750	δ (COO⁻) bending (formate)	[42, 44, 45, 48]
750	ν (Si–O–Si) stretching asymmetric (glass)	[47, 49]