Extra‐Large Mechanical Anisotropy of a Hydrogel with Maximized Electrostatic Repulsion between Cofacially Aligned 2D Electrolytes. Issue 38 (29th August 2018)

• Record Type: Journal Article
• Authors: Sano, Koki; Arazoe, Yuka Onuma; Ishida, Yasuhiro; Ebina, Yasuo; Osada, Minoru; Sasaki, Takayoshi; Hikima, Takaaki; Aida, Takuzo
• Is Part Of: Angewandte Chemie international edition. Volume 57:Issue 38(2018)
• Page Start: 12508
• Page End: 12513
• Publication Date: 2018-08-29
• Subjects: anisotropy -- composite materials -- electrostatic repulsion -- hydrogels -- materials science; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201807240
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: In our previous work, we have shown that "electrostatic forces", when generated anisotropically in aqueous media by 2D electrolytes upon cofacial orientation, enable the formation of a hydrogel with an anisotropic parameter, as defined by the ratio of elastic moduli E ⊥ / E ∥, of 3.0. Herein, we successfully developed the design strategy for a hydrogel with an anisotropic parameter of no less than 85. This value is not only 28 times greater than that of our previous anisotropic hydrogel but also 6 times larger than the current champion record in synthetic hydrogels ( E ⊥ / E ∥ ∼15). Firstly, we simply lowered ionic contaminants in the hydrogel and were able to enhance the anisotropic parameter from 3.0 to 18. Then, we chose a supporting polymer network allowing the hydrogel to carry a higher interior permittivity. Consequently, the anisotropic parameter was further enhanced from 18 to 85. Owing to the enhanced mechanical anisotropy, our new hydrogel displayed a superb ability of seismic isolation. Abstract : An extraordinarily anisotropic hydrogel was developed by maximizing the electrostatic repulsion between cofacially aligned 2D electrolytes using two rational strategies. The anisotropic parameter of the hydrogel reaches a value of 85, which is far beyond the current champion record of about 15 among synthetic anisotropic hydrogels. The new hydrogel exhibited an excellent ability of seismic isolation.