Piperidinium-functionalized PAEK membrane

High-temperature acid recovery with exceptional flux-selectivity

By constructing confined ionic channels via selective swelling, it simultaneously achieves high acid flux and high selectivity at 75 °C, breaking the typical flux-selectivity trade-off.

Feixiang, Zhai · Zhang, Bengui · Liu, Qian · Jingjun, He · Zhihan, Song · Hanqi, Jia · Jiaxin, Kang · Zhang, Enlei · Wang, Kangjun · Zhou, Mingdong

Separation and Purification Technology 2026

Specifications

Acid dialysis coefficient
{'zh': '97.21', 'en': '97.21'} × 10⁻³ m h⁻¹
Separation factor
{'zh': '138.94', 'en': '138.94'}
Acid dialysis coefficient
{'zh': '115.45', 'en': '115.45'} × 10⁻³ m h⁻¹
Separation factor
{'zh': '118.65', 'en': '118.65'}
Ion-exchange capacity range
{'zh': '0.911–2.030', 'en': '0.911–2.030'} mmol g⁻¹
Acid dialysis coefficient
{'zh': '38.18', 'en': '38.18'} × 10⁻³ m h⁻¹

Advantages

High flux and selectivity at high temperature

Selective swelling by hot phosphoric acid induces microphase separation, forming continuous yet confined nanoscale ionic channels; the acid dialysis coefficient increases markedly with temperature and IEC while high separation factors are maintained.

Tunable IEC

Tertiary-amine piperidine groups quaternized via a mild Menshutkin reaction enable tunable ion-exchange capacity (IEC = 0.911–2.030 mmol g⁻¹).

Surpasses commercial membrane

Compared with commercial DF-120 membrane, PiPEK-14 exhibited 4.58-fold higher U_H⁺ and 5.50-fold higher S at 75 °C.

Applications