Abstract

Cellulose is one of the most abundant resources in nature. Cellulose-based porous monoliths have been fabricated by direct drying of oil-in-water high internal phase emulsions (HIPEs) stabilized using either cellulose derivatives or surface-modified cellulose. The resulting cellulose-based porous polymers, however, were usually fragile, reflecting the lack of crosslinking. Herein, we report a new strategy to fabricate cellulose-based porous materials (polyurethane polyHIPEs, PU polyHIPEs) templated within non-aqueous HIPEs through the covalent crosslinking between isocyanates and unmodified cellulose. The PU polyHIPEs exhibited interconnected macroporous structures and exhibited tunable wettability from hydrophilicity/oleophilicity to hydrophobicity/oleophilicity. The PU polyHIPEs were able to absorb a wide variety of oils, exhibiting relatively large capacities and high absorption rates. We further showed that the PU polyHIPEs were robust, and they did not fail under compressive stress even at strains of 70%. The robustness, large absorption capacities, rapid absorption, and hydrophobicity/oleophilicity make these cellulose-based PU polyHIPEs suitable for oil absorption and/or oil–water separation applications.

Graphic abstract

中文翻译：

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在非水高内相乳液中模板化的纤维素基，高孔隙度聚氨酯

摘要

纤维素是自然界中最丰富的资源之一。通过直接干燥使用纤维素衍生物或表面改性纤维素稳定的水包油高内相乳液（HIPE），可以制造出纤维素基多孔整料。然而，所得的基于纤维素的多孔聚合物通常是易碎的，反映出缺乏交联。在本文中，我们报告了一种通过异氰酸酯和未改性纤维素之间的共价交联制备非水性HIPE中模板化的纤维素基多孔材料（聚氨酯polyHIPE，PU polyHIPE）的新策略。PU polyHIPEs表现出相互连接的大孔结构，并且表现出从亲水性/亲油性到疏水性/亲油性的可调润湿性。PU polyHIPEs能够吸收多种油，表现出相对大的容量和高吸收率。我们进一步表明，PU polyHIPEs坚固耐用，即使在70％应变下也不会在压缩应力下失效。这些纤维素基PU polyHIPE的坚固性，大吸收能力，快速吸收和疏水性/亲油性使其适用于吸油和/或油水分离应用。

图形摘要