Enhanced broadband near-IR luminescence and gain spectra of bismuth/erbium co-doped fiber by 830 and 980 nm dual pumping AIP Advances 7, 045012 (2017) A simple approach to preparing dopamine-modified polypropylene fibers with a controllable polydopamine amount is supplied. By the dopamine modification, the hydrophobic polypropylene fibers have been changed into hydrophilic. The hydrophilicity can be improved by increasing the amount of polydopamine, as revealed by the contact angle evolutions. The hydrophilic dopamine-modified polypropylene fibers can rapidly and effectively remove copper and lead ions in water. Moreover, the performance of removing heavy metals is prominently improved as the polydopamine amount increases. This is because the polydopamine introduction can supply many available sites for adsorbing heavy metal ions, as revealed by theoretical simulation results. These results are crucial in future engineering fiber filters towards efficiently removing heavy metal ions using dopamine-modified polypropylene fibers. © 2017 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license