Poly(ionic liquid)‐Armored MXene Membrane: Interlayer Engineering for Facilitated Water Transport

Abstract

Two‐dimensional (2D) MXene‐based lamellar membranes bearing interlayers of tunable hydrophilicity are promising for high‐performance water purification. The current challenge lies in how to engineer the pore wall's surface properties in the subnano‐confinement environment while ensuring its high selectivity. Herein, poly(ionic liquid)s, equipped with readily exchangeable counter anions, succeeded as a hydrophilicity modifier in addressing this issue. Lamellar membranes bearing nanochannels of tailorable hydrophilicity are constructed via assembly of poly(ionic liquid)‐armored MXene nanosheets. By shifting the interlayer galleries from being hydrophilic to more hydrophobic via simple anion exchange, the MXene membrane performs drastically better for both the permeance (by two‐fold improvement) and rejection (≈99 %). This facile method opens up a new avenue for building 2D material‐based membranes of enhancing molecular transport and sieving effect.

Can MXene be the Effective Nanomaterial Family for the Membrane and Adsorption Technologies to Reach a Sustainable Green World?

“…The average molecular weight cutoff (MWCO) for the composite membrane was reported as in between 600 and 800 Da considering the analysis based on the different molecular weight of PEG molecules . Compared with the free-standing membranes where only the pure MXene was fabricated on a polymeric support, , MXene/polymer composite membranes − offered almost twice the water flux with stable dye rejection performance.…”

“…Due to the synergy between these novel polymers and MXene, which leads to the enhancement in hydrophilicity of the membrane, water flux improved almost twice. Interestingly, poly­(ionic liquid)­s including counteranions was proposed as a hydrophilicity modifier, which alters the water transport and rejects dyes selectively via a precise selection of the counterion . An intriguing approach was also suggested by the group of Wu, who fabricated MMM using PES and Ti 3 C 2 T x /ZIF-8 nanocomposite synthesized via a facile one-pot microemulsion strategy.…”

“…This superior performance was ascribed to the ability of Ag to improve the resistance of membrane towards organic foulants via its hydrophilic nature. Most 193 Wei et al, 194 Liu et al, 227 Feng et al, 229 Zhang et al, 211 Long et al, 215 Tong et al, 219 Yi et al, 224 Gong et al, 233 Kim et al, 237 He et al, 214 and Tao et al 217 ). Arrows represent the alteration in MXene content in a nanocomposite membrane.…”

Achieving fast interfacial solar vapor generation and aqueous acid purification using Ti3C2TxMXene/PANI non-woven fabrics

“…2b and c, the thickness of Ti 3 C 2 T x nanosheets dispersed in organic solvent was 1.7 nm, with an average lateral size of 2.8 mm, which indicated that the as-synthesized Ti 3 C 2 T x should be regarded as monolayer nanosheets. 35 After concentrating by centrifugation, ordered liquid crystals could be found in both Ti 3 C 2 T x and Ti 3 C 2 T x /aniline organic solvent dispersions, with a concentration ranging from 15 mg mL À1 to 40 mg mL À1 , and their morphology was captured by polarized optical microscopy (POM) shown in Fig. S3 (ESI †) and Fig.…”

All-pseudocapacitive coordination towards flexible asymmetric fiber-shaped supercapacitors with ultrahigh energy and power density

“…1h). The spectrum of the Ti 3 C 2 T x sample shows major peaks at 202, 281, 389, and 608 cm −1 , which are induced by the vibrations of Ti and C. 36,37 Raman signals of rGO include a D-band ($1348 cm −1 ) associated with the defect-activated breathing modes of six-membered carbon rings and a G-band ($1588 cm −1 ) assigned to graphitic carbon. 38 As for MXrG bers, the D-and G-characteristic peaks exhibit a certain degree of red shi, such as 1349 to 1343 cm −1 and 1588 to 1584 cm −1 , which is probably induced by the enlarged conjugate area between Ti 3 C 2 T x and rGO nanosheets.…”