Sustainable transparent wood focusing on lignin decolorization methods, polymer impregnation techniques and applications in functional buildings: A review.

The utilization of transparent wood as a potential composite derived from wood offers numerous advantages, including exceptional mechanical properties, lightweight, low thermal conductivity and immense potential for multifunctionality. Additionally, transparent wood demonstrates commendable performance in both thermal insulation and light transmission management, contributing to the reduction of energy consumption. This makes it an attractive option for buildings and related engineering elements. However, despite the successes achieved to date, further improvement is still required in terms of overall sustainability and functionality to meet the demands of advanced applications. This paper provides a comprehensive summary of the transparent wood preparation process, highlighting the efforts made to improve sustainability through various approaches. These strategies encompass using environmental-friendly chemicals or methods for lignin decolorization, substituting petroleum-based polymers with bio-based alternatives, and increasing the cellulose content through densification techniques. In addition, this paper presents the functionalization aspects of transparent wood such as chromism, heat shielding properties, ultraviolet shielding properties, luminescence, and fire-resistance, as well as its building applications. Finally, the challenges currently encountered in the development and application of transparent wood are discussed with an emphasis on the necessity for additional exploration and advancement in this area.