Successful preparation of high-performance ultra-thin carbon dioxide separation membrane

Separation performance meets industrial application requirements

Separation performance meets industrial application requirements

Sinochem News Network News on August 16, from the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, the team of Researcher Yang Weishen and Associate Researcher Peng Yuan of the Inorganic Membrane and Catalytic New Materials Research Group was working on a pure-phase covalent organic framework (COFs).
) New progress has been made in the research of gas separation membranes, and high-performance ultra-thin carbon dioxide separation membranes have been prepared, and the separation performance has reached the requirements of industrial applications
.

According to Peng Yuan, the carbon dioxide separation membrane they prepared uses COFs nanosheets as the membrane building element to induce the staggered shrinkage effect and realize the preferential permeation and separation of carbon dioxide in the carbon dioxide/hydrogen mixture
.

In other words, the two-dimensional COFs framework has a synergistic effect on the selective adsorption of carbon dioxide and the staggered shrinkage effect of the nanosheets, which can induce the gas diffusion mechanism on the inner surface of the membrane, thereby realizing the efficient separation of carbon dioxide

Because the pore size of two-dimensional COFs is larger than 0.
8 nanometers, it is difficult to achieve precise separation of small molecular gases with dynamic diameters of 0.
3 to 0.
4 nanometers, such as hydrogen (0.
29 nanometers) and carbon dioxide (0.
33 nanometers).
Therefore, a pure phase two with high-efficiency carbon dioxide separation performance can be constructed.
Dimensional COFs membranes face great challenges
.

"However, COFs materials have permanent one-dimensional through pores, rich surface functional groups and excellent stability, and still have huge application potential in the field of carbon dioxide separation

Based on this, on the basis of previous research, the team developed a weak acid solvent stripping method based on three layered COFs with different surface chemistry and pore size as the research object, and used a gentle mechanical external force method to strip them.
For a series of ultra-thin nanosheets with a thickness of 2 nanometers and sizes up to micrometers, a pure phase COFs membrane with a pore size suitable for carbon dioxide separation is constructed by precisely controlling the staggered assembly of the nanosheets
.

　　In the context of the goal of carbon peak and carbon neutrality, the development of low-energy, environmentally friendly carbon dioxide selective separation membranes is of great significance and practical application value
.

Compared with traditional high-energy-consuming separation technologies such as solvent absorption and cryogenic distillation, pressure-driven membrane separation technology has extremely low energy consumption and small carbon footprint, meeting the strategic needs of sustainable development of industry and society

　　Peng Yuan said that the carbon dioxide separation membrane they developed is still in the laboratory verification stage.