Newly Developed Nano-Calcium Carbonate and Nano-Calcium Propanoate for the Deacidification of Library and Archival Materials

Figure 1

Raman spectra (excitation line λ = 785 nm) of papers, showing three possible degradations occurring in the cellulose chain. The characteristic peaks are marked with arrows. Blue line: formation of carboxylic groups (636 cm⁻¹ O=C–O i.p. deformation; 1444 cm⁻¹ O=C–O sym. stretching; 1577 cm⁻¹ O=C–O asym. stretching). Red line: formation of carbon-carbon double bonds (634 cm⁻¹ C=C–H wagging; 1577 cm⁻¹ C=C–O stretching). Black line: formation of a five-member cyclic ether (716 C–O sym. stretching; 1079 cm⁻¹ C–O asym. stretching). The ether is formed after oxidative breaking of C2–C3 bond in the anhydroglucose ring and subsequent rearrangement with formation of an ether linkage between C3 and C6 [2].