Abstract Shape memory driving thickness adjustable graphite (G) micro-flakes@shape memory polyurethane (G@SMPU) sponge was fabricated by two-step dipping separately in G-dispersed aqueous solution and SMPU/THF solution for high-performance microwave shielding. The sponge exhibited an ultrahigh G loading ratio (G/sponge, wt/wt) up to 490 wt%. For the first time, dipping coating of SMPU onto the sponge was proposed, and the obtained G@SMPU sponge exhibited a good recovery effect at least above 90% after thorough compression. And also, the thickness could be adjusted by utilizing its shape memory property. For microwave shielding, G-9@SMPU and G-18@SMPU sponges achieved the shielding effectiveness over 20 and 30 dB, respectively. Moreover, varying thickness or compressing repeatedly even up to 100 times would not obviously decrease the shielding effect of the G@SMPU sponge. This suggests the steady distribution and adhesion of G micro-flakes inside the three-dimensional sponge substrate due to the fixing of SMPU.

中文翻译：

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形状记忆驱动厚度可调的 G@SMPU 海绵具有超高碳负载比，具有出色的微波屏蔽性能

摘要 形状记忆驱动厚度可调石墨（G）微薄片@形状记忆聚氨酯（G@SMPU）海绵分别在G-分散水溶液和SMPU/THF溶液中两步浸渍，用于高性能微波屏蔽。海绵表现出高达 490 wt% 的超高 G 负载比（G/海绵，wt/wt）。首次提出将SMPU浸涂到海绵上，得到的G@SMPU海绵在彻底压缩后至少表现出90%以上的良好恢复效果。此外，还可以利用其形状记忆特性来调整厚度。对于微波屏蔽，G-9@SMPU 和 G-18@SMPU 海绵分别实现了超过 20 和 30 dB 的屏蔽效果。而且，改变厚度或重复压缩甚至高达 100 次也不会明显降低 G@SMPU 海绵的屏蔽效果。这表明由于 SMPU 的固定，G 微薄片在三维海绵基材内的稳定分布和粘附。