Polyetheretherketone (PEEK) has been becoming a popular implant material in orthopaedic applications. The lack of bioactivity affects PEEK’s long-term lifetime, and appropriate surface modification is an effective way to enhance its bioactivity. Sulfonation of PEEK can endow PEEK with a 3 D porous network surface and improve its bioactivity. This study is aimed at exploring an optimal sulfonation time and a post-treatment method of PEEK sulfonation. PEEK was immersed into concentrated sulfuric acid for different sulfonation times and experienced different post-treatment methods to turn into sulfonated PEEK (SPEEK). The immersion times were 0.5 min (SPEEK0.5), 1 min (SPEEK1), 3 min (SPEEK3), 5 min (SPEEK5) and 7 min (SPEEK7), and the post-treatment methods were acetone rinsing (SPEEK-T1), hydrothermal treatment (SPEEK-T2) and NaOH immersion (SPEEK-T3). Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy, hydrophilic property, ion release and cell viability evaluations were performed to optimize the sulfonation time, and the SEM, EDS, ion release and cell viability were analysed to optimize the post-treatment method. The results showed a porous network structure was formed on all samples of SPEEK, and the porous structure became more obvious and the S concentration increased with increasing sulfonation time. However, too long of an immersion time (SPEEK7) tended to damage the superficial porous structure and left a higher content of sulfuric acid, which could inhibit the growth of MC3T3E1 cells on its surface. In addition, the surface morphology, residual sulfuric acid and cytocompatibility of SPEEK-T1, SPEEK-T2 and SPEEK-T3 were not distinctly different. In conclusion, a 5-min sulfonation time was considered to be the optimal selection, and acetone rinsing, hydrothermal treatment and NaOH immersion showed the same effect in removing the residual sulfuric acid. The understanding of optimal sulfonation time and post-treatment method can provide a theoretical basis in preparing SPEEK for orthopaedic applications.

聚醚醚酮 (PEEK) 已成为骨科应用中流行的植入材料。缺乏生物活性会影响 PEEK 的长期使用寿命，适当的表面改性是增强其生物活性的有效途径。PEEK的磺化可以赋予PEEK以3D多孔网络表面并提高其生物活性。本研究旨在探索PEEK磺化的最佳磺化时间和后处理方法。PEEK在浓硫酸中浸泡不同的磺化次数，经过不同的后处理方法，最终变成磺化PEEK（SPEEK）。浸泡时间分别为0.5分钟(SPEEK0.5)、1分钟(SPEEK1)、3分钟(SPEEK3)、5分钟(SPEEK5)和7分钟(SPEEK7)，后处理方法为丙酮漂洗(SPEEK-T1) , 水热处理 (SPEEK-T2) 和 NaOH 浸泡 (SPEEK-T3)。进行扫描电子显微镜（SEM）、能量色散光谱（EDS）、傅里叶变换红外光谱、亲水性、离子释放和细胞活力评估以优化磺化时间，并分析SEM、EDS、离子释放和细胞活力。优化后处理方法。结果表明，所有SPEEK样品均形成了多孔网络结构，并且随着磺化时间的增加，多孔结构变得更加明显，S浓度增加。然而，过长的浸泡时间 (SPEEK7) 往往会破坏表面多孔结构，并留下更高含量的硫酸，这会抑制其表面 MC3T3E1 细胞的生长。此外，表面形貌，SPEEK-T1、SPEEK-T2和SPEEK-T3的残留硫酸和细胞相容性没有明显差异。总之，磺化时间为5分钟被认为是最佳选择，丙酮漂洗、水热处理和NaOH浸泡在去除残留硫酸方面表现出相同的效果。了解最佳磺化时间和后处理方法可为制备用于骨科应用的 SPEEK 提供理论依据。