Researchers propose adaptive and accurate healing of stress-induced dynamic cracks in membranes

Stress-induced cracks often lead to catastrophic failure of materials. For membranes, stress loads concomitant with thermal and mechanical risks during separation will gradually produce cracks, which weaken the stability and reliability of membranes in long-term separation processes.

Recently, a research group led by Prof. YANG Weishen and Prof. BAN Yujie from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences proposed adaptive healing of stress-induced dynamic cracks (AHSDC) in a metal-organic framework membrane using nanoparticles. This study was published in Science Advances.

Traditional post crack-healing technologies, due to the spatiotemporal mismatch between crack formation and crack healing, lack point-by-point healing accuracy and result in a large healing zone, thus leading to increased membrane thickness and mass transfer resistance.

In this study, to create spatiotemporal harmony between generation and healing of cracks was chosen as the core and AHSDC was proposed.

AHSDC leveraged risk factors to overcome the membrane's tolerance limits and made stress-induced dynamic cracks fully exposed prior to separation. At the same time, it employed in situ formed nanoparticles in the same chemical environment to immediately fill crack gaps once cracks formed in the membrane.

The research group proved that AHSDC could function with point-by-point accuracy and form adaptive healing zones with the ability of self-selecting their shapes according to peculiarities of cracks.

The membrane after AHSDC retained satisfactory separation performances for azeotropic mixtures with energy consumption saved by approximately 85%. Besides, the separation durability was improved by at least two orders of magnitude.