Fig. 6: Characteristics of All-Cel foam: formability, recyclability, biodegradability, and environmental impact.

a Digital images showcasing All-Cel foams shaped into various forms. The flower-shaped (i) and raindrop-shaped (ii) foams were prepared by pouring cellulose molecular solution into corresponding molds, followed by ethanol exchange. For the wave-shaped (iii) and bridge (iv) shaped foams, preformed All-Cel foam panels were first softened in water, then placed into custom molds, and finally reshaped via ethanol exchange. b Demonstration of the capability to process large-sized All-Cel foam panels (47 × 28 × 3 cm), highlighting the scalability and potential for practical applications such as thermal insulation and structural panels. c Illustration of the recyclability process for All-Cel foam. The used All-Cel foam can be shredded into chips and re-dissolved to form a cellulose system. The regenerated All-Cel foam is fabricated via pouring the cellulose system into a mold to create a new foam embryo, and followed by ethanol-induced self-assembly. This process demonstrates All-Cel foam’s sustainable lifecycle. d Biodegradability tests of All-Cel foam and traditional plastic foams (PP, EPS, and PU) over time under natural soil environment, with intervals ranging from 0 to 160 days. As degradation time progressed, the All-Cel foam gradually lost structural integrity and visibly decomposed, whereas the traditional plastic foams remained nearly unchanged throughout the entire period. e Assessment of the environmental impacts of All-Cel foam relative to commonly used plastics (PP, EPS, and PU), with each impact category normalized by the material with the highest impact.