Abstract In the present work, microfibrillated cellulose (MFC) suspensions were produced by high-pressure homogenization and subsequently used to fabricate MFC membranes (C-1) by vacuum filtration followed by hot-pressing. A polyketone (PK50) was chemically modified by Paal-Knorr reaction to graft imidazole (IM) functional groups along its backbone structure. The resulting polymer is referred to as PK50IM80. By solution impregnation, C-1 was immersed in an aqueous solution of PK50IM80 and subsequently hot pressed, resulting in the fabrication of MFC/PK50IM80 composite membranes (C-IMP). Another method, referred to as solution mixing, consisted in adding MFC into an aqueous solution of PK50IM80 followed by vacuum filtration and hot-pressing to obtain MFC/PK50IM80 composite membranes (C-MEZC). C-IMP and C-MEZC were characterized by a wide range of analytical techniques including, X-ray photoelectron spectroscopy, Fourier-transform infrared chemical imaging, scanning electron microscopy, atomic force microscopy, dynamical mechanical analysis, tensile testing as well as streaming zeta potential, and compared to C-1 (reference material). The results suggested that C-IMP possess a more homogeneous distribution of PK50IM80 at their surface when compared to C-MEZC. C-IMP was found to possess significantly enhanced Young's modulus compared to C-1 and C-MEZC. The tensile strength of C-IMP was found to improve significantly compared to C-1, whereas C-1 possessed significantly higher tensile index than C-IMP and C-MEZC. Furthermore, the presence of PK50IM80 at the surface of MFC was found to significantly shift the isoelectric point (IEP) of the membranes from pH 2.3 to a maximum value of 4.5 for C-IMP. Above the IEP, C-IMP and C-MEZC were found to possess significantly less negative electrical surface charges (plateau value of −25 mV at pH 10) when compared to C-1 (plateau value of −42 mV at pH 10). Our approach may have implication to broaden the range of filtration applications of MFC-based membranes.

中文翻译：

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微纤化纤维素/咪唑改性聚酮复合膜的机械性能和表面电荷

摘要 在目前的工作中，微纤化纤维素 (MFC) 悬浮液通过高压均质化生产，随后通过真空过滤和热压用于制造 MFC 膜 (C-1)。聚酮 (PK50) 通过 Paal-Knorr 反应进行化学改性，以沿其骨架结构接枝咪唑 (IM) 官能团。所得聚合物称为PK50IM80。通过溶液浸渍，将 C-1 浸入 PK50IM80 的水溶液中，然后进行热压，从而制备出 MFC/PK50IM80 复合膜（C-IMP）。另一种称为溶液混合的方法包括将 MFC 添加到 PK50IM80 的水溶液中，然后真空过滤和热压以获得 MFC/PK50IM80 复合膜 (C-MEZC)。C-IMP 和 C-MEZC 的特征在于广泛的分析技术，包括 X 射线光电子能谱、傅里叶变换红外化学成像、扫描电子显微镜、原子力显微镜、动态力学分析、拉伸试验以及流式 zeta潜力，并与 C-1（参考材料）进行比较。结果表明，与 C-MEZC 相比，C-IMP 在其表面具有更均匀的 PK50IM80 分布。发现 C-IMP 与 C-1 和 C-MEZC 相比具有显着增强的杨氏模量。与 C-1 相比，C-IMP 的拉伸强度显着提高，而 C-1 的拉伸指数明显高于 C-IMP 和 C-MEZC。此外，发现 MFC 表面 PK50IM80 的存在使膜的等电点 (IEP) 从 pH 2.3 显着移动到 C-IMP 的最大值 4.5。在 IEP 之上，发现 C-IMP 和 C-MEZC 与 C-1（pH 10 的平台值 -42 mV）相比具有显着更少的负表面电荷（pH 10 的平台值 -25 mV）。我们的方法可能意味着扩大基于 MFC 的膜的过滤应用范围。