The First Graphene "Space Sponge" Can Withstand Temperatures At 1000 Degrees Centigrade And -269 Degrees Centigrade.

According to Nankai news network, after many years of continuous research, Professor Chen Yongsheng of the school of chemistry, Nankai University, and the United States Rice University jointly developed a new type of three-dimensional graphene material in April 2019.

The material can withstand the temperature range of 4K (about -269 degrees) to 1273K (about 1000 degrees Celsius), and can maintain good moisture stability and high elasticity. It is expected to become a space sponge in the field of aerospace equipment manufacturing. The relevant research results were published in Science Advances in April 12, 2019.

High elastic material is a kind of material with large reversible deformation ability, such as common rubber, polymer foam material and so on. It has been widely used in human production and life.

The new high elastic materials have great application prospects in high-end research and technology fields such as wearable devices, artificial muscles and sensors.

However, almost all elastic properties and other mechanical properties of all high elastic materials are affected by temperature.

For example, silicone rubber is softened or decomposed at high temperature; on the contrary, it loses elasticity gradually with temperature drop and becomes vitrified and hardened and brittle.

The same problem also exists in high elastic polymer foam or sponge materials.

The "space sponge" material is made up of disordered single layer graphene sheets, which are formed by covalent bond chemical crosslinking. It has the same mechanical properties at room temperature as the lowest temperature at low liquid helium temperature zone, including highly recoverable super elasticity, constant Young's modulus (physical quantities describing solid material resistance to deformation), near zero Poisson's ratio (elastic constants reflecting pverse deformation of materials) and excellent fatigue resistance.

Team researchers pointed out that no other material has been reported to have such super elastic properties at low temperature and elastic and mechanical properties which are not affected by temperature in the temperature range from 4K to 1273K.

Through the self built mechanical performance testing system, the Chen Yongsheng team has accurately and systematically tested the mechanical properties of three dimensional graphene materials in the temperature range of 4-1273K (about -269 to 1000 degrees). The deformation characteristics of 3D graphene materials in the compression springback process were obtained by using the team scanning electron microscope and in situ temperature changing sample stage. The verification of theoretical models verified that the temperature invariance of the new material originates from the graphene specific SP2 hybrid two-dimensional carbon atom planar crystal structure.

The research team points out that the outstanding mechanical stability of graphene and three-dimensional graphene materials under low temperature conditions makes it the best research object for applications in outer space and other extreme low temperatures or harsh environments.

Other two-dimensional nanomaterials, if there are structures similar to graphene, such as Shi Moque, Silene, planar germanium and two-dimensional Bi1 xSbx sheets, will be assembled in the way similar to three-dimensional graphene in the form of structural units. The macroscopic materials obtained may also retain the unique properties of two-dimensional structural units and exhibit macroscopic specific properties.

It is reported that the study was completed by the team of Professor Chen Yongsheng of Nankai University and Professor Pulickel Ajayan of Rice University, and was supported by the Ministry of science and technology and the National Natural Science Foundation of China.

Article link: https://advances.sciencemag.org/content/5/4/eaav2589