A New Concept of Pseudo-Janus Structure: Employing Yin-Yang Fish Structure Film with Up/down Conversion Fluorescence and Bi-anisotropic Conduction to Represent Pseudo-Janus Structure as a Case Study
The Yin-Yang Fish, a sign of traditional Chinese culture, has been widely used to represent the combination of two different properties or the transformation between them in the field of materials chemistry. Inspired by Yin-Yang Fish sign, here, a concept of structure very different from Janus structure is proposed in materials chemistry, and it is defined as pseudo-Janus structure. The pseudo-Janus structure can be regarded as a new structure which is obtained by flipping one side of the Janus structure vertically. The symmetry of the pseudo-Janus structure is different from that of Janus structure. For Janus structure, the symmetries are mirror and π symmetry, while for the pseudo-Janus structure, the symmetries are central and π symmetry. The Yin-Yang Fish sign is a typical pseudo-Janus structure. Herein, employing Yin-Yang Fish structure film representing pseudo-Janus structure as a case study, we have fabricated an pseudo-Janus structure film (defined as PF) with multi-modes fluorescence and bi-anisotropic conductivity by electrospinning. The two fish-like structure regions of PF are constructed by Janus nanoribbons and the two eye-like regions consist of nanofibers. The PF achieves macro-partition of four independent functional domains to obtain excellent synchronous bi-anisotropic conduction, up- and down-conversion multi-modes luminescence to avoid harmful mutual interferences. Janus nanobelt, realizing micro-partition of two functional domains, is used as building unit to construct fish-like regions to microscopically reduce detrimental influences among different functions by isolating and confining them in their own domains, and thus ensuring high conductive anisotropy and strong fluorescence. Micro-partition and macro-partition are highly integrated in the pseudo-Janus structure film to achieve excellent multi-functionality. Pseudo-Janus structural design is also applicable to construct other multi-functional materials with different structures or properties.