New green solvent system alkali (such as NaOH and LiOH)/urea which could rapidly dissolve cellulose could be potentially used to prepare high-performance regenerated cellulose materials with low cost. Pure regenerated cellulose materials have relatively low strength inherent effects. In this work, we choose TEMPO-oxide cellulose nanofiber (CNF) and graphene oxide (GO) as fillers to prepare isotropic regenerated cellulose membrane (RCM) with significantly enhanced mechanical properties. Dynamic mechanical analyzer (DMA) test shows that RCM with content of 5 wt% CNF has the maximum enhancement value of 32.5% improvement comparing with pure RCM. And RCM with 0.4 wt% GO has the maximum improvement of 17.9%. Mechanical properties decrease with further increasing filler contents. We employ transmission electron microscopy to confirm the structure of fillers in solution and scanning electron microscopy to observe the microstructures of these RCMs. The results are consistent with DMA tests. In addition, XRD results confirm that the crystal structure of RCMs is the same with RCMs without filler. Thermogravimetric analyses results indicate that RCMs keep great thermal stability below 300 °C. Transmittance (T_r) property is carried out by UV–Vis spectroscopy. Pure RCMs and CNF/RCMs keep high transparency at the wavelength of 800 nm. Transparency of RCMs with GO decrease quickly when the content of GO increases. In conclusion, the enhancement mechanism is proposed as the addition of fillers makes up the defects in RCMs. Furthermore, CNF illustrates large aspect ratio which is beneficial for stress transfer. As for GO, polar groups on surface provide strong interaction with the matrix. This is the first time that the enhancement effects of different fillers are systematically analyzed and compared for RCMs system. Our work could benefit the selection of appropriate fillers for such green solvent system and expand its range of applications.

可以快速溶解纤维素的新型绿色溶剂体系碱（例如NaOH和LiOH）/脲可以潜在地以低成本制备高性能的再生纤维素材料。纯再生纤维素材料具有相对较低的强度固有效应。在这项工作中，我们选择TEMPO-氧化物纤维素纳米纤维（CNF）和氧化石墨烯（GO）作为填料，以制备具有显着增强的机械性能的各向同性再生纤维素膜（RCM）。动态机械分析仪（DMA）测试显示，CNF含量为5 wt％的RCM与纯RCM相比，最大增强值为32.5％。GO含量为0.4 wt％的RCM的最大改进为17.9％。机械性能随着填料含量的进一步增加而降低。我们使用透射电子显微镜确定溶液中填料的结构，并使用扫描电子显微镜观察这些RCM的微观结构。结果与DMA测试一致。另外，XRD结果证实RCM的晶体结构与不具有填料的RCM相同。热重分析结果表明，RCM在300°C以下保持良好的热稳定性。透光率T _r）特性通过UV-Vis光谱法进行。纯RCM和CNF / RCM在800 nm波长处保持高透明度。随着GO含量的增加，带有GO的RCM的透明度会迅速下降。总之，提出了增强机制，因为添加了填料可以弥补RCM中的缺陷。此外，CNF显示了宽高比，这有利于应力传递。对于GO，表面上的极性基团可与基质形成强烈的相互作用。这是首次针对RCMs系统对不同填料的增强效果进行系统分析和比较。我们的工作可能有益于为此类绿色溶剂系统选择合适的填料，并扩大其应用范围。