The effect of chemical treatment on green color preservation and surface characteristics of Neosinocalamus affinis bamboo

Abstract

Bamboo culms or bamboo plywood possessing a native green surface color are highly valuable for use in interior decoration. However, the green surface color of bamboo can easily become discolored in ambient environments without any protection. In order to maintain the green surface color of Neosinocalamus affinis bamboo, this study used copper sulfate (CuSO4), phosphoric acid (H3PO4), and acetic acid (CH3COOH) solutions as protectors. The changes in surface color and characteristics of the bamboo samples before and after the treatment were evaluated. The results showed that the N. affinis bamboo samples treated with 2% CuSO4 solution at 80 °C for 3 h exhibited an attractive green color, with a* and b* values of -7.61 and 5.13, respectively. The indoor durability test result indicated that bamboo samples treated with CuSO4, CuSO4/H3PO4, and CuSO4/CH3COOH solutions all had excellent color durability. After the treatment, the relative copper content on the bamboo surface slightly increased, while the magnesium content decreased. The chlorophyll structure was changed, and reactions between chlorophyll and copper ions may have occurred. The silicon was almost completely removed, and the surface structure of the treated bamboo changed, resulting in good permeability for the treatment.