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

Table 1

Treatments of original documents (18th century) with nano-calcium carbonate in propan-2-ol.

pH before treatment	pH after treatment
Paper: 6.5 ± 0.1	Paper: 10.1 ± 0.1
Ink: 5.1 ± 0.1	Ink: 9.9 ± 0.1
Colour coordinates before treatment	Colour coordinates after treatment
Paper:	Paper:
L = 91.79 ± 0.12	L = 90.39 ± 0.36
a = +0.08 ± 0.02	a = +0.19 ± 0.03
b = +11.15 ± 0.18	b = +10.85 ± 0.14
Ink:	Ink:
L = 63.87 ± 1.63	L = 69.34 ± 1.25
a = +1.05 ± 0.82	a = +3.02 ± 0.89
b = +14.66 ± 0.54	b = +13.52 ± 1.24