Ultrafast Water Transport in Two‐Dimensional Channels Enabled by Spherical Polyelectrolyte Brushes with Controllable Flexibility

Abstract

Fast water transport channels are crucial for water‐related membrane separation processes. However, overcoming the trade‐off between flux and selectivity is still a major challenge. To address this, we constructed spherical polyelectrolyte brush (SPB) structures with a highly hydrophilic polyelectrolyte brush layer, and introduced them into GO laminates, which increased both the flux and the separation factor. At 70 °C, the flux reached 5.23 kg m−2 h−1, and the separation factor of butanol/water increased to ≈8000, which places it among the most selective separation membranes reported to date. Interestingly, further studies demonstrated that the enhancement of water transport was not only dependent on the hydrophilicity of the polyelectrolyte chains, but also influenced by their flexibility in the solvent. Quartz crystal microbalance with dissipation and molecular dynamics simulations revealed the structure‐performance correlations between water molecule migration and the flexibility of the ordered polymer chains in the 2D confined space.

ZnO nanodots on graphene for lithium-ion energy storage

“…Hence, it is essential to incorporate other materials into graphene in order to open the channel for electrolyte ions and increase the SSA of graphene. Usually, the folding and stacking of graphene were improved by inserting soft polymers, including cationic porphyrin, [5] polyacrylonitrile gel, [6] polyelectrolyte brush [7] to adjust the ion transport behavior in graphene oxide. However, the effect of adding polymer additives is usually very limited, mainly due to the inherent elastoplasticity of the polymer and its uneven distribution on the surface of graphene oxide.…”