A new type of graphene foam hole chip network topology model

Recently, Dr. Wang Xiaojie, a researcher at the Institute of Advanced Manufacturing Technology of Hefei Institute of MaterialScience of the Chinese Academy of Sciences, and Wang Chao, Ph.D., of the Institute of Aesthetics of the Chinese Academy of Sciences, successfully constructed a three-dimensional hole network topology model with both the original hole and the hinge key on the basis of the quasi-two-dimensional graphite sheet model through careful study of graphene foam hinges and defective SEM mirror images. By introducing hinged bond force field parameters and hole-to-chip characteristic geometry, they reasonably realized the effective evaluation of the dynamic behavior of the proposed real graphene foam by means of coarse granulation dynamics.
Graphene foam, which is a three-dimensional porous material articulated from quasi-two-dimensional graphene as the basic component and articulated by disorderly stacking as the main construction method, belongs to
a typical form of carbon
sponge; Because of the advantages of both graphene and porous materials, graphene foam has received more and more attention from the scientific and technological circles at home and abroad. However, according to a large number of experimental studies, the physical mechanism behind the excellent performance of the foam is not clear, the stress transfer characteristics of quasi-two-dimensional graphene recombination into a three-dimensional network are also lacking in understanding, and the interstitiogenic evolution process of graphene foam when it is overloaded cannot be reproduced in place. In this context, in the past three years, some micro-nanoscale theoretical research has gradually begun.
Because the structural complexity of the foam material itself limits the application of theoretical research methods, the existing computational models are made up of perfect graphene, and the actual graphene foam is a layered porous structure formed by chemical or physical hinges containing defects or holes in the real graphite, which results in a serious dissociation between theory and experiments.
With the help of the hole chip network (Figure 1), the researchers not only made systematic predictions of single-axis supercompression and reply behavior under various operating conditions, but also used the mechanics test data in the relevant literature to assist in testing; In addition, the researchers further constructed a new type of graphite ring foam, and a systematic comparative analysis with the perfect graphene foam and the fitting real porous foam found that this new line structure and perfect foam skeleton in ultra-elastic performance, especially in reply behavior is not as realistic as intended Foam system, which theoretically tells the experimenter that instead of worrying about the graphene's natural hole in graphene foam, the focus should be on regulating the hole ratio of the foam and the shape or number of holes (materials to achieve "waste as treasure").
It is worth pointing out that the study also found the interesting interlocking phenomenon inside the foam (Figure 2), according to which the plastic deformation and residual deformation from the microstructive evolution mechanism made a detailed distinction, enriching the connotation of continuous media aesthetics; The average length of the coarse grain key has an abnormal change point with the change curve of the external load, which is about 70% to 80% of the compression strain, which makes a scientific quantitative definition of the abstract concept of hypercompression from the meso-scale.
results were published recently in the international journal Nano (ACS Nano, 2018, 12 (11), 11491-11502). Pan Dooxing is the first author and correspondent of the thesis, Wang Chao is the second author and Wang Xiaojie is the co-author of the communication. The work was funded by the National Natural Science Foundation of China and the Chinese Academy of Sciences' "Programme for the Introduction of Outstanding Technical Talents".