Optically Transparent Bamboo with High Strength and Low Thermal Conductivity.

The objective of this study is to convert bamboo into a transparent material with great optical transmittance and good strength. Bamboo has a much faster regeneration rate than wood, but its high density and high extractive content make it challenging to produce transparent products. This study presents a simple and effective approach that could address this challenge. Pretreatment of bamboo with low concentration sodium hydroxide greatly improved the preparation efficiency of transparent bamboo. The transparent bamboo with a thickness of 1 mm and cellulose volume fraction of 22% made from the pretreated bamboo exhibited an improved total optical transmissivity up to 80%, which was 60% higher than that of untreated bamboo. Compared to transparent wood (TW), although the transmissivity of transparent bamboo was slightly lower, its mechanical strength was almost doubled. Besides, the developed transparent bamboo exhibited a low heat conductivity of 0.203 W m-1 K-1, being about 10% lower than that of TW (0.225 W m-1 K-1) and approximately 80% lower than that of common glass material (0.974 W m-1 K-1). The transparent bamboo would significantly enhance energy-saving performance, being a promising alternative to traditional glass.