Optimization and absorption performance of wood sponge.

Wood can be used for the in situ preparation of wood sponge using chemical treatment, which can be employed as absorbent for sewage treatment and exhibits the advantage of low cost, low density, high porosity, and environmental friendliness. Previous researches on wood sponge mainly focused on its various applications, while the influence rule and mechanism of treatment conditions such as pH and concentration of NaClO₂ solution, as well as concentration of NaOH solution have not been fully understood. This challenge limits the manufacturing efficiency and further application of wood sponge for the production of absorption materials and so on. The study presented an effective strategy for preparing wood sponges via using a top–down chemical treatment on low-density balsa wood and paid more attention to the controlling rule of preparation parameters. At the condition that pH of 4.0 (NaClO₂ solution), NaOH concentration of 7 wt%, and NaClO₂ concentration of 3 wt%, wood sponge with a porosity of 96.47% can be obtained with good resilience and excellent absorption capacity. Excessive concentration of NaOH and NaClO₂ will significantly affect the skeletal structure of the wood sponge. After the silylation treatment, the optimal wood sponge was endowed with oil and organic solvents absorption capacity of 2441–17,300 mg g⁻¹; it can be also recycled by simple extrusion. This highly resilient and recyclable wood sponge with high porosity and oil absorption capacity can be potentially applied for environmental protection. [ABSTRACT FROM AUTHOR]