Universal and tunable liquid\u2013liquid separation by nanoparticle-embedded gating membranes based on a self-defined interfacial parameter

Xiangyu Li,Huajun Zhai,Hanshi Hu,Weifeng Zhang,Yanan Liu,Jingjing Liu,Ruixiang Qu,Yen Wei,Lin Feng

doi:10.1038/s41467-020-20369-9

Xiangyu Li, Huajun Zhai + Show 7 more

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https://doi.org/10.1038/s41467-020-20369-9

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Journal: Nature Communications	Publication Date: Jan 4, 2021
Citations: 34	License type: open-access

Affiliation: Tsinghua University, Beihang University

Abstract

Superwetting porous membranes with tunable liquid repellency are highly desirable in broad domains including scientific research, chemical industry, and environmental protection. Such membranes should allow for controllable droplet bouncing or spreading, which is difficult to achieve for low surface energy organic liquids (OLs). Here we develop an interfacial physical parameter to regulate the OL wettability of nanoparticle-embedded membranes by structuring synergistic layers with reconfigurable surface energy components. Under the tunable solid-liquid interaction in the aggregation-induced process, the membranes demonstrate positive/negative liquid gating regularity for polar protic liquids, polar aprotic liquids, and nonpolar liquids. Such a membrane can be employed as self-adaptive gating for various immiscible liquid mixtures with superior separation efficiency and permeation flux, even afford successive achievement of high-performance in situ extraction-back extraction coupling. This study should provide distinctive insights into intrinsic wetting behaviors and have pioneered a rational strategy to design high-performance separation materials for diverse applications.

Highlights

Superwetting porous membranes with tunable liquid repellency are highly desirable in broad domains including scientific research, chemical industry, and environmental protection
The transmission electron microscopy (TEM) images reveal that these resulting TiO2 nanoparticles possess a uniformsize multi-granulous structure with a diameter of about 50 nm (Supplementary Fig. 2)
The aforementioned result is consistent with the atomic force microscopy (AFM) images that the thickness of a single nanoparticle increases smoothly to ~50 nm (Fig. 2b)

Summary

Introduction

Superwetting porous membranes with tunable liquid repellency are highly desirable in broad domains including scientific research, chemical industry, and environmental protection Such membranes should allow for controllable droplet bouncing or spreading, which is difficult to achieve for low surface energy organic liquids (OLs). The primary strategy is assigned to regulate the SEs of the membranes between the intrinsic wetting thresholds of two immiscible OLs, resulting in the permeating of low SE liquid and the blocking of high SE liquid Based on such a mechanism, there are some excellent works about the superwetting materials used for the OL separation including TiO2 fibrous membrane modified with long-chain silanes[28], fluorosilane-doped polyvinylidene fluoride membrane[29], fluorinated CuO or Cu(OH)[2] nanoneedle mesh[30,31], fluorinated graphene/metal-organic framework composite membrane[32], and so forth. This work provides a paradigm for the OL wetting mechanism to build an efficient bridge between arbitrary liquids and superwetting systems, and unlock additional possibilities for the intelligent fluid-related systems owing to the simplicity, versatility, and low cost of the nanofabrication technique

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