Flexible cellulose-based conductive films reveal high potential in electromagnetic interference (EMI) shielding and thermal management applications. However, the high contact electrical/thermal resistance in these films is still a challenge to face. In this work, an asymmetric sandwich structural film containing a cellulose nanofiber (CNF) skin-layer and self-supported Ti₃C₂T_x MXene and silver nanowire (AgNW) core-layers (CNF@MXene@AgNW film) was fabricated through layer-by-layer assembled vacuum-assisted filtration. The unique sandwich structure not only provides a highly conductive network by the highly oriented and self-supported conductive core-layers, but also maintains its structural integrity by ambilateral CNF layers. As a result, the CNF@MXene@AgNW film reveals a strong tensile strength of 118 MPa and a toughness of 4.75 MJ m⁻³, super-flexibility (minimum bending radius of ∼85 μm), a high electrical conductivity (37 378.2 S m⁻¹), effective EMI shield effectiveness (SE, 55.9 dB), outstanding specific SE (SSE/t, 10 647.6 dB cm² g⁻¹) and high in-plane thermal conductivity (15.53 W m⁻¹ K⁻¹), simultaneously. More interestingly, the sandwich film also reveals outstanding solar-thermal energy conversion ability, which guarantees its normal function in extremely cold environment. The unique asymmetric sandwich structure provides a new strategy for designing and preparing high-performance EMI shielding and thermal conductive films.

中文翻译：

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具有自支撑MXene和AgNW层的非对称三明治结构纤维素基薄膜，可实现灵活的电磁干扰屏蔽和热管理

柔性纤维素基导电膜在电磁干扰（EMI）屏蔽和热管理应用中显示出很高的潜力。然而，这些膜中的高接触电阻/热阻仍然是面临的挑战。在这项工作中，包含纤维素纳米纤维（CNF）表层和自支撑Ti ₃ C ₂ T _x的不对称夹心结构膜MXene和银纳米线（AgNW）核心层（CNF @ MXene @ AgNW膜）是通过逐层组装的真空辅助过滤而制成的。独特的夹层结构不仅通过高度定向和自支撑的导电芯层提供了高导电网络，而且还通过单边CNF层保持了其结构完整性。结果，CNF @ MXene @ AgNW薄膜显示出118 MPa的强拉伸强度和4.75 MJ m ^-3的韧性，超柔韧性（最小弯曲半径约为85μm ），高电导率（37 378.2 S） m ^-1），有效的EMI屏蔽效果（SE，55.9 dB），出色的特定SE（SSE / t，10 647.6 dB cm ² g ^-1）和高的平面内热导率（15.53 W m ^-1 K ^-1）。更有趣的是，该夹层膜还具有出色的太阳热能转换能力，从而保证了其在极冷环境下的正常功能。独特的不对称夹层结构为设计和制备高性能EMI屏蔽和导热膜提供了新的策略。