Para-aramid nanofiber membranes (ANFMs) have gained significant attention owing to their excellent properties. However, the preparation of ANFM remains a challenge. The amount of entanglement in the ANF dispersion is insufficient, which is why the ANFM cannot be prepared directly through conventional spinning methods. Therefore, we proposed an airflow-assisted coaxial spinning (AFAS) method. A flexible polymer (polyethylene oxide (PEO)), was employed as the outer spinning solution for improving the spinnability of the precursor solution, thus facilitating the efficient preparation of a well-shaped ANFM. The AFAS method reported herein is effective for preparing para-aramid nanofibers and ANFMs. ANFM was successfully fabricated by AFAS, consisting of nanoscale superfine ANFs ranging from 20 to 25 nm, a small average pore size of 0.2 μm, and high porosity (exceeding 80 %). Additionally, the ANFM exhibits prominent mechanical properties (tensile strength = 88.3 MPa; Young's modulus: E = 1.5 GPa), good flexibility, an excellent flame retardancy and thermal stability (300 °C) and flame retardancy.

中文翻译：

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气流辅助同轴纺丝制备超细对位芳纶纳米纤维及膜


对位芳纶纳米纤维膜（ANFM）由于其优异的性能而受到广泛关注。然而，ANFM 的准备仍然是一个挑战。 ANF分散体中的缠结量不足，这就是为什么ANFM不能直接通过常规纺丝方法制备的原因。因此，我们提出了气流辅助同轴纺丝（AFAS）方法。采用柔性聚合物（聚环氧乙烷（PEO））作为外层纺丝溶液，以提高前驱体溶液的可纺性，从而有利于有效制备形状良好的ANFM。本文报道的 AFAS 方法对于制备对位芳纶纳米纤维和 ANFM 是有效的。通过AFAS成功制备了ANFM，由20至25 nm的纳米级超细ANF组成，平均孔径小至0.2 μm，孔隙率高（超过80%）。此外，ANFM还表现出突出的机械性能（拉伸强度= 88.3 MPa；杨氏模量：E = 1.5 GPa）、良好的柔韧性、优异的阻燃性和热稳定性（300℃）和阻燃性。