A research group led by Susumu Kitagawa, director of the Institute for Integrated Cell-Materials Sciences (iCeMS) at Kyoto University, in collaboration with research groups in Ireland and the United States, absorbed carbon dioxide and carbon monoxide to transform the shape. Furthermore, we succeeded in developing a soft porous crystal that remembers its shape.This is a result that leads to new materials that enable efficient storage and separation of various gases.
A material that keeps its shape once memorized is called a shape memory material, and it keeps memorizing its shape unless it is overheated.Metal alloys are used as the material.It has a wide range of uses such as eyeglass frames and medical materials.In this research, we succeeded in synthesizing a porous crystal that adsorbs gas molecules and exhibits a shape memory phenomenon, and clarified the mechanism of the memory for the first time.
This porous crystal has a network structure in which organic molecules and metal ions are bonded and assembled in a jungle gym shape, and has innumerable nano-sized pores inside.Before adsorbing gas, the jungle gym is distorted and the pores are closed, but when it absorbs gas molecules such as carbon dioxide, it deforms and the pores open, and even if the gas is discharged, the pores do not close.That is, once a jungle gym crystal inhales gas, it memorizes its shape.However, it can be restored to its original closed shape by heating to 120 degrees or higher.It is thought that if this property is used, it becomes easy to control the pores, such as opening the gas when it is desired to be sucked and closing it when it is not desired to be sucked, which enables a complicated gas separation process.
The elucidation of the mechanism of shape memory crystals, which has been a mystery until now, will lead to the development of various materials showing similar properties.It is expected to be applied to new materials that solve difficult problems such as separation and storage of various gases such as carbon dioxide.
Paper information:[Science Advances] Readyly accessible shape-memory effect in a porous interpenetrated coordination network
