- Precisely Encoding Geometric Features into Discrete Linear Polymer Chains for Robust Structural Engineering
-
Molecular shape is an essential parameter that regulates the self-organization and recognition process, which has not yet been well appreciated and exploited in block polymers due to the lack of precise and efficient modulation methods. This work (i) develops a robust approach to break the intrinsic symmetry of linear polymers by introducing geometric features into otherwise homogeneous chains and (ii) quantitatively highlights the critical contribution of molecular geometry/architecture to the self-assembly behaviors. Iteratively connecting homologous monomers of different side chains according to pre-designed sequences generates discrete polymers with exact chemical structure, uniform chain length, and programmable side-chain gradient along the backbone, which transcribes into diverse shapes. The precise chemistry eliminates all the defects and heterogeneities, providing a delicate platform for fundamental inquiries into the role of molecular geometry. A rich collection of unconventional complex phases, including Frank-Kasper A15 and σ phases, as well as a dodecagonal quasicrystal phase, were captured in these rigorous single-component systems. The self-assembly behaviors are strikingly sensitive to subtle variations of geometry, such that simply migrating a few methylene units among the side chains would generate substantial differences in lattice size or phase stability, or even trigger a phase transition toward distinct structures. The phenomena can be rationalized with a geometric argument that nonuniform side chain distribution leads to conformational mismatch between two immiscible blocks, resulting in varied interfacial curvatures and distinct lattice symmetries. The profound contribution demonstrates that molecular geometry is an effective and robust parameter for structural engineering.
- Zhou, Dongdong,Xu, Miao,Ma, Zhuang,Gan, Zhanhui,Tan, Rui,Wang, Shuai,Zhang, Zhengbiao,Dong, Xue-Hui
-
supporting information
p. 18744 - 18754
(2021/11/16)
-
- Butyryl glutamic acid derivative as well as composition and application thereof
-
The invention discloses a butyryl glutamic acid derivative as well as a composition and application thereof. The butyryl glutamic acid derivative disclosed by the invention or a racemic modification,stereisomer, geometric isomer, tautomer and solvate or feed-acceptable salt thereof can be applied in the preparation of novel feed additives and feeds. The invention further discloses a feed composition of the butyryl glutamic acid derivative or the racemic modification, the stereisomer, the geometric isomer, the tautomer and the solvate or the feed-acceptable salt thereof. When applied in animalhusbandry, the butyryl glutamic acid derivative provided by the invention has the effect of improving the production performance of animals, such as increasing animal weight increasing rate, decreasing feed conversion ratio and controlling diarrhea rate, and can be applied as an effective, safe novel feed additive.
- -
-
Paragraph 0154; 0155; 0161
(2018/07/30)
-