Environmentally benign methods for producing green culms of ma bamboo (Dendrocalamus latiflorus) and moso bamboo (Phyllostachys pubescens)

The objective of this study was to find an effective method for treating ma bamboo (Dendrocalamus latiflorus) and moso bamboo (Phyllostachys pubescens) using new water-based reagents containing copper. The effects of green-color protection using various treatments on bamboo culms were examined in this study. Two methods were used: heating in a water bath and ultrasonic dipping. The results revealed that excellent green-color protection (a* value of −6.2) was obtained when ma bamboo culms were treated with 0.25% ammoniacal copper quaternary compound-type B (ACQ-B) in a water bath at 100°C for 2 h. It was also found that the wettability of bamboo epidermis increasedsignificantly after pretreatment in a mixture of 1% KOH and surfactant in a water bath at 100°C for 30 min. Furthermore, pretreated moso bamboo culms exhibited excellent green-color protection after they were treated with 0.25% ACQ-B at 100°C for 2 h (a* value of −8.2). This novel treatment method definitely endows the bamboo culms with a fascinating green skin color and consequently could increase the economic value of bamboo products. No improvement in green-color protection was found when ultrasonic energy was added to the water bath at ambient temperature.