To extend the potential application of ultrasonic treatment in dyeing lowquality wood to improve decorative value, wood veneers were dyed with an ultrasonic assisted dyeing system. The effects of ultrasonic power, dye concentration, dyeing time, and temperature of ultrasonic-assisted treatment on dye-uptake, chromatic value, crystallinity, thermal stability, chemical structure, and microstructure for dyed wood veneer were investigated. The dye-uptake, chromatic value, and dyeing rate were improved by ultrasonic-assisted treatment. The effect was strengthened with an increase in ultrasonic power, dye concentration, and dyeing time and temperature. After ultrasonic treatment, the dyed wood properties such as lignin degradation, crystallization and thermal stability decreased slightly, and part of the wood microstructure such as the pit membrane and parenchyma cells was mechanically damaged. Ultrasonic-assisted treatment enhanced the permeability of wood by creating new fluid channels and sorption sites, and it is believed to be an energy-efficient and environmental wood dyeing technique.

Three-dimensional (3D) conductive aerogels with structural robustness and mechanical resilience are highly attractive for sensitive and stable pressure sensing. However, the fabrication of such 3D aerogels often relies on complicated bottom-up assembly processes that involve costly raw materials or intensive energy consumption or directly coating synthetic polymer sponges (e.g., polyurethane) with conductive materials, which may pose environmental concerns for their disposal. Herein, a simple and sustainable strategy is proposed to fabricate a reduced graphene oxide-coated wood sponge (RGO@WS) with a lamellar structure for high-performance piezoresistive sensors. The introduced RGO nanosheets endow the RGO@WS not only with high conductivity but also with high elasticity and excellent fatigue resistance. These features make it an ideal piezoresistive sensor with a high sensitivity of 0.32 kPa–1 (superior to most polymeric sponge-based sensors), high working stability over 10 000 cycles, and excellent sensing reproducibility at ultralow temperatures. Thanks to its prominent sensing performance, the RGO@WS-based sensor can serve as a wearable device for detecting human motions and physiological signals and allows for spatially resolved pressure mapping via integrating the sensors into a large-area sensing array. The developed highly elastic and fatigue-resistant RGO@WS represents a promising and sustainable alternative to the synthetic polymer-based piezoresistive sensors.

The dyeing properties of basswood veneer treated by dichlorotriazine reactive dye in a dip dyeing method were evaluated. The effects of dye concentration, dyeing temperature and time, volume ratio, and dyeing agent were observed relative to the dye-uptake and K/S, using gray correlation analysis. Results showed that various dip dyeing factors had remarkable influences on dye-uptake and K/S, especially dyeing temperature and volume ratio. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX) results indicated that reactive dyes were successfully combined with basswood and diffused into the wood fiber lumens and ray cells. Furthermore, thermogravimetric analysis (TGA) demonstrated that the residue of dyed veneer was higher than undyed, and the temperature at maximum degradation rate of dyed and undyed veneer was different.

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