Wood-based superblack

Abstract

Light is a powerful and sustainable resource, but it can be detrimental to the performance and longevity of optical devices. Materials with near-zero light reflectance, i.e. superblack materials, are sought to improve the performance of several light-centered technologies. Here we report a simple top-down strategy, guided by computational methods, to develop robust superblack materials following metal-free wood delignification and carbonization (1500 °C). Subwavelength severed cells evolve under shrinkage stresses, yielding vertically aligned carbon microfiber arrays with a thickness of ~100 µm and light reflectance as low as 0.36% and independent of the incidence angle. The formation of such structures is rationalized based on delignification method, lignin content, carbonization temperature and wood density. Moreover, our measurements indicate a laser beam reflectivity lower than commercial light stoppers in current use. Overall, the wood-based superblack material is introduced as a mechanically robust surrogate for microfabricated carbon nanotube arrays.

Size/Shape-Controllable Carbonized Wood Electrodes Enabled by an MXene Shell with Spatial Confinement and a Traction Effect on the Wood Cell Wall for Shape-Customizable Energy Storage Devices

“…The high carbon content enables wood to exhibit good electrical conductivity after carbonization at a high temperature of ∼1000 °C, accompanied by unpredictable deformations and damage to the physical structure of the wood. , The volumetric shrinkage of woods (Figures S12 and S13) at different carbonization temperatures proves that the deformation behavior of wood during carbonization mainly occurs in the temperature range of 200–400 °C . Therefore, understanding the concept behind this temperature range is the key to harnessing the shrinkage of the CW.…”

Competitive and Environmentally Sustainable Bioproducts: Mild Top-Down Processing of Biomass to Renewable Carbon

“…Nevertheless, the results must be interpreted with caution because the data for biocolloids are often derived from laboratory or pilot-scale processes, leaving considerable room for optimization. Besides, it is important to recognize the significant benefits of isolating pure bioproducts, in terms of their contribution to fundamental research and their exploitation in certain value-added applications, such as photonic pigments (e.g., chiral nematic cellulose nanocrystals), 14 superblack materials (e.g., delignified and carbonized wood), 15 or mechanical reinforcement at very low fractions (e.g., cellulose nanocrystals in cement paste). 16 The question is whether it is efficient to increase costs and environmental impacts through extensive top-down processing to obtain materials with insufficient technical improvements that do not pay for the up-front environmental/economic burdens.…”