Effect Of Paper Deacidification With Nano Calcium Hydroxide and Nano Hydroxyapatite, With Nano Cellulose And Nano Chitosan On Its Anti-Fungal Properties

Abstract

Several factors cause the degradation of cellulose that the most important factor of them is Acidic Hydrolysis. Many historical books are gradually destroyed due to acidic hydrolysis and reduction of the degree of polymerization of cellulose. So deacidification and strengthening treatments for valuable old papers to stop these processes are necessary. Since the paper is a good substrate for growth of some destroying fungi, applying a suitable restoration treatment to stop or delay the growth of these destroying microorganisms - in addition of increasing the pH and preparing alkaline conditions for paper- has been considered. In this study, in order to deacidification and strengthening of paper, with different combinations of Nano Calcium hydroxide, Nano Hydroxyapatite, Nano cellulose and Nano Chitosan in an alcoholic solvent )ethanol), a Nano coat was applied on the surface of the sample paper. For study the anti-fungal properties, biologic aging was done on treated paper with Aspergillus fungi. For this purpose, after preparing culture medium, treated papers in separate petri dishes were inoculated and after incubation period, the amount of fungal growth was studied. Also, tensile strength test was done on treated samples. Results showed that diacidifation treatments by preparing an alkaline condition increased the pH of paper and the paper treated with a complex of Nano calcium hydroxide and Nano chitosan, and also treated samples with Nano Hydroxyapatite had lowest fungal contamination. Treated Papers with Nano calcium hydroxide and Nano chitosan showed better tensile strength properties and applying Nano cellulose in treatments improved the tensile strength of treated papers although had the less anti-fungal resistance.

Keywords

• Paper deacidification treatment
• Nano Hydroxyapatite
• Cellulose Nano fibers
• Chitosan
• Aspergillus fungi