Introduction

On December 8, 2017, one research paper named “Bioinspired graphene membrane with temperature tunable channels for water gating and molecular separation” by Professor Zhao Yong, Associate Professor Wang Nü from the School of Chemistry was published in Nature Communications. Professor Zhao and Associate Professor Wang are corresponding authors, Dr. Liu Jingchong is the first author and Beihang University is the first corresponding organization.

Source of Achievement

The source of this achievement comes from a key project funded by the National Natural Science Foundation of China on the design and preparation of bioinspired separation membrane which was shared by Prof. Zhao and Associate Professor Wang. Their mission is to make a sieve-like separation membrane which can separate the required component from the mixture. Previously, they had developed oil-water separation, emulsion separation and oil-oil separation membranes, and under this basis, they hope to develop a separation membrane which has higher precision to separate nanoscale molecules. What is more, compared to traditional membranes, this membrane should be “smart” that its channel size could be tuned under external simulus. Thus it can separate molecules with different sizes step-wisely, which can simplify the steps of waste water treatment.

Learning from Nature

After deliberate consideration and literature research, the team selects graphene oxide as the ideal separation membrane. The space between the stacked graphene oxide sheets provide the unique 2D nanochannels for molecule transport. They further work on constructing the membrane with tunable channel size in a bionic way.

In order to keep water balance of itself, plant will close its stomata at high temperature and open its stomata at low temperature. Learning from nature, the team fabricated a composite separation membrane composed of a temperature-responsive polymer and graphene oxide. This temperature-responsive polymer smartly shrinks at high temperature, while swelling at low temperature. Thereby, the channel size of this bioinspired separation membrane decreases at high temperature and increases when the temperature is low.

Cooperation Leading to Success

Dr. Liu Jingchong had worked on this project for 2 years in order to construct the smart graphene-based separation membrane successfully. He did a large amount of experiments and explored the temperature-responsive performance of the separation membrane once and again under the guidance of Professor Zhao and Associate Professor Wang.

Associate Professor Wang mentioned some details about this project. During the research process, Liu Jingchong occasionally found that two data he got were inconsistent with the results reported by the published papers. After repeating the experiments, they proved their results both in experimental and theoretically. And these two unusual data are quite important to the success of this whole project.  

What is more, cooperation is also very important. During his visiting to Harvard University in 2016, Professor Zhao discussed with a teacher from Shanghai University whose research focuses on responsive polymer materials. The teacher provided a lot of valuable suggestions to the mechanism explanation. For the part of theoretic calculation, one researcher from the Australian National University also gave many help.

The team can not succeed without full research enthusiasm, rich knowledge reserve, excellent inspiration, exploration of details, repeated experiments and cooperation. In the new year, we hope research teams of Beihang dare to be the first and get more fruits!

Interviewed by Li Xinxin, Zeng Jiaqi, Liu Xinrui and Tan Lisha

Edited by Liu Xinxin and Zeng Jiaqi

Translated by Liu Xinrui