Abstract

In this work, a large size of macroporous phenolic resin (PR)/bacterial cellulose (BC) composite with double-network structure was fabricated simply by soaking, heating, solvent exchange, and ambient pressure drying. The mechanism and influence factors for the fabrication of this macroporous composite were systematically elaborated. One network of macroporous composite was composed of PR beads, and the other derived from original BC nanofibers. They supported and reinforced each other, avoiding the collapse of interconnected porous structure and achieving low density (0.29 g/cm³), high porosity (77.7%), low thermal conductivity (0.10 W/m K), and excellent compressive strength (7.97 ± 2.24 MPa). Through further carbonization, carbon counterpart that maintained fine structure and good performance can also be obtained. The surface of macroporous composite was extremely hydrophilic. On the contrary, its carbon counterpart possessed a highly hydrophobic surface (contact angle = 118.2°). These properties suggest that the macroporous composite and carbon counterpart may have potential applications for filtration, separation, and thermal insulation materials. Moreover, this work will provide a novel perspective for the fabrication of porous composites with BC as the template and 3D nanofiber reinforcement simultaneously.

Graphic abstract

中文翻译：

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常压干燥制得的具有双网状结构的强韧大孔酚醛树脂/细菌纤维素复合材料

摘要

在这项工作中，仅通过浸泡，加热，溶剂交换和常压干燥即可简单地制备大尺寸的具有双网状结构的大孔酚醛树脂（PR）/细菌纤维素（BC）复合材料。系统地阐述了制备这种大孔复合材料的机理和影响因素。大孔复合材料的一个网络由PR珠组成，另一个网络由原始BC纳米纤维衍生而成。它们相互支撑和加强，避免了相互连接的多孔结构塌陷并实现了低密度（0.29 g / cm ³），高孔隙率（77.7％），低导热率（0.10 W / m K）和出色的抗压强度（7.97±2.24 MPa）。通过进一步碳化，也可以获得保持精细结构和良好性能的碳对应物。大孔复合材料的表面非常亲水。相反，它的碳对应物具有高度疏水的表面（接触角= 118.2°）。这些性质表明，大孔复合材料和碳的对应物可能具有过滤，分离和隔热材料的潜在应用。此外，这项工作将为同时以BC为模板和3D纳米纤维增强材料的多孔复合材料的制造提供新颖的视角。

图形摘要