
Citation:
ZHANG Guoyao, YI Guozheng, LIU Dong, WU Liheng. CRYSTALLIZATION BEHAVIOR OF A THERMOTROPIC LIQUID CRYSTAL COPOLYESTER*[J]. Chinese Journal of Polymer Science,
;1993, 11(2): 109-114.
-
A thermotropic liquid crystal copolyester resin based on p-hydroxybenzoic acid, 2, 6-naphthoic acid, hydroxyquinone and PET was synthesized by melt condensation and studied. The results based on DSC and X-ray diffraction indicated that there were a rapid and a slow crystallization processes for the copolyester at certain conditions. A critical temperature was suggested, below which the slow crystallization could hardly happen. Above the critical temperature the extent of the slow crystallization process depended not only on annealing temperature but also on the annealing time.A fine crystal structure with high melting point and narrow diffraction peak was formed under favorable conditions.
-
Solid-state chemistry is drawing increasing attention due to the rise of solid-state electrolytes (SSEs). SSEs enable the accelerated migration of multiple anions such as lithium (Li) and sodium at solid-state mode. Compared with routine organic liquid electrolytes in Li batteries, solid Li ionic conductors (SSLCs) can realize high thermal stability, high ionic conductivity, and wide electrochemical windows, which enables the application of Li metal anodes[1]. Consequently, SSLCs have been treated as a promising solution to break through the anxiety of limited energy density of conventional Li-ion batteries. Tremendous efforts have been devoted to this field and have achieved significant progresses[2]. However, the experimentally synthesized solid electrolytes cannot meet the multiple requirements in practical batteries, which is calling for emerging methodology and instructions to explore advanced solid-state electrolytes.
Figure 1
Figure 1. Unsupervised clustering results for Li contained compounds. Most high ionic conductive materials are located in groups V and VI, which possess mild distortion anion structures. The materials in groups V and VI exhibit obvious talents of high ionic conductivity[11], which are concentrated for the subsequent screeningThe known SSLCs exhibit various crystalline structures, including layered patterns (Li3N), garnet (Li7La3Zr2O12), NASICON (Li1.5Al0.5Ti0.5(PO4)3), perovskite (Li0.5La0.5TiO3), anti-perovskite (Li3OX, X = Cl and Br), thio-LISICON (Li10GeP2S12, LGPS) and argyrodite (Li6PS5X, X = Cl, Br, and I)[3-7]. These typical ionic conductors possess disparate crystalline structure, physical/chemical properties, and ionic conductivities, whose internal connection is difficult to be completely analyzed and unraveled. Therefore, designing brand-new Li ionic conductive materials confronts tremendous challenges. Conventional explorations depending on experimental try and errors are not effective. Based on the already known materials, a rapid exploration and screening impel the development of material genome engineering[8]. Mo and co-authors have conducted much beneficial work towards the prediction of (electro)chemical stability against Li metal and the electrochemical window of multiple solid-state electrolytes, affording an accurate guidance for interfacial engineering[9, 10]. The supervised learning methods require abundant data to train the models. A large amount of involved data guarantees the accuracy of the trained model. However, the kinds of known SSLCs are insufficient to conduct supervised machine learning with a high accuracy. Most Li contained compounds do not possess high ionic conductivities, which cannot be treated as training materials. In order to figure out the disadvantages, Mo, Ling, and co-workers creatively conducted an unsupervised machine learning study, which is a new route to unravel the interior differences between SSLCs and thus can predict new potential SSLCs[11]. The unsupervised machine learning model simultaneously divides the data into different groups according to data characteristics.
In the unsupervised model, the authors designed a protocol as follows: digitalizing Li-contained compounds, clustering the targeted groups, and running ab initio molecular dynamics (AIMD) simulations to verify the predicted objects. The anion framework of Li-contained compounds is firstly digitalized by the modified XRD (mXRD) representation. In order to highlight the structural crystal features, only the anion framework is considered. The mXRD means that the characteristics of the anion frameworks are transformed into a group of lattice parameters shown in XRD patterns. Each compound will be simplified into a vector. Then the mXRD clustering classified compounds by their characteristics of their anion framework structures. The Li ions located in the highly symmetric lattices are constrained at the well-defined sites. The highly disordered framework will also locally trap ions and hinder possible percolations. It is concluded that anion frameworks with a mild distortion, which are located between the highly symmetric lattices and the highly disordered ones, possess high ionic conductivities. This fruitful insight affords a great reference for further screening of ionic conductors. The groups with mild distortion are further screened by AIMD simulation to choose objects with high ionic conductivities. More significantly, the unsupervised method dramatically shrinks the range for screening and increases screening efficiency compared with the conventional high throughput methods. The unsupervised machine learning is appropriate to estimate potential materials with high ionic conductivities. The results for screening also provide targets for experimental attempts. Because the new predicted materials exhibit disparate crystal structures, the results can also help to broaden the thoughts.
The solid Li ionic conductor is a complicated system, involving many chemical and physical parameters. This unsupervised machine learning system does not cover sufficient details in solid Li ionic conductors. Therefore, the accuracy of the machine learning model can be further improved. The unsupervised machine learning method is a new brand route for predictions, integrating the high throughput results towards screening solid-state lithium ion conductors for next-generation batteries.
-
-
-
[1]
Jiakun Bai , Junhui Jia , Aisen Li . An elastic organic crystal with piezochromic luminescent behavior. Chinese Journal of Structural Chemistry, 2024, 43(6): 100323-100323. doi: 10.1016/j.cjsc.2024.100323
-
[2]
Jun Lu , Jinrui Yan , Yaohao Guo , Junjie Qiu , Shuangliang Zhao , Bo Bao . Controlling solid form and crystal habit of triphenylmethanol by antisolvent crystallization in a microfluidic device. Chinese Chemical Letters, 2024, 35(4): 108876-. doi: 10.1016/j.cclet.2023.108876
-
[3]
Yang Li , Yihan Chen , Jiaxin Luo , Qihuan Li , Yiwu Quan , Yixiang Cheng . Enhanced circularly polarized luminescence emission promoted by achiral dichroic oligomers of F8BT in cholesteric liquid crystal. Chinese Chemical Letters, 2024, 35(11): 109864-. doi: 10.1016/j.cclet.2024.109864
-
[4]
Yarui Li , Huangjie Lu , Yingzhe Du , Jie Qiu , Peng Lin , Jian Lin . Highly efficient separation of high-valent actinide ions from lanthanides via fractional crystallization. Chinese Journal of Structural Chemistry, 2025, 44(4): 100562-100562. doi: 10.1016/j.cjsc.2025.100562
-
[5]
Yuan Liu , Boyang Wang , Yaxin Li , Weidong Li , Siyu Lu . Understanding excitonic behavior and electroluminescence light emitting diode application of carbon dots. Chinese Chemical Letters, 2025, 36(2): 110426-. doi: 10.1016/j.cclet.2024.110426
-
[6]
Tong Zhang , Xiaojing Liang , Licheng Wang , Shuai Wang , Xiaoxiao Liu , Yong Guo . An ionic liquid assisted hydrogel functionalized silica stationary phase for mixed-mode liquid chromatography. Chinese Chemical Letters, 2025, 36(1): 109889-. doi: 10.1016/j.cclet.2024.109889
-
[7]
Hongdao LI , Shengjian ZHANG , Hongmei DONG . Magnetic relaxation and luminescent behavior in nitronyl nitroxide-based annuluses of rare-earth ions. Chinese Journal of Inorganic Chemistry, 2024, 40(5): 972-978. doi: 10.11862/CJIC.20230411
-
[8]
Yan Zou , Yin-Shuang Hu , Deng-Hui Tian , Hong Wu , Xiaoshu Lv , Guangming Jiang , Yu-Xi Huang . Tuning the membrane rejection behavior by surface wettability engineering for an effective water-in-oil emulsion separation. Chinese Chemical Letters, 2024, 35(6): 109090-. doi: 10.1016/j.cclet.2023.109090
-
[9]
Siwei Wang , Wei-Lei Zhou , Yong Chen . Cucurbituril and cyclodextrin co-confinement-based multilevel assembly for single-molecule phosphorescence resonance energy transfer behavior. Chinese Chemical Letters, 2024, 35(12): 110261-. doi: 10.1016/j.cclet.2024.110261
-
[10]
Yinling HOU , Jia JI , Hong YU , Xiaoyun BIAN , Xiaofen GUAN , Jing QIU , Shuyi REN , Ming FANG . A rhombic Dy4-based complex showing remarkable single-molecule magnet behavior. Chinese Journal of Inorganic Chemistry, 2025, 41(3): 605-612. doi: 10.11862/CJIC.20240251
-
[11]
Qihou Li , Jiamin Liu , Fulu Chu , Jinwei Zhou , Jieshuangyang Chen , Zengqiang Guan , Xiyun Yang , Jie Lei , Feixiang Wu . Coordinating lithium polysulfides to inhibit intrinsic clustering behavior and facilitate sulfur redox conversion in lithium-sulfur batteries. Chinese Chemical Letters, 2025, 36(5): 110306-. doi: 10.1016/j.cclet.2024.110306
-
[12]
Hongxia Li , Xiyang Wang , Du Qiao , Jiahao Li , Weiping Zhu , Honglin Li . Mechanism of nanoparticle aggregation in gas-liquid microfluidic mixing. Chinese Chemical Letters, 2024, 35(4): 108747-. doi: 10.1016/j.cclet.2023.108747
-
[13]
Peng Meng , Qian-Cheng Luo , Aidan Brock , Xiaodong Wang , Mahboobeh Shahbazi , Aaron Micallef , John McMurtrie , Dongchen Qi , Yan-Zhen Zheng , Jingsan Xu . Molar ratio induced crystal transformation from coordination complex to coordination polymers. Chinese Chemical Letters, 2024, 35(4): 108542-. doi: 10.1016/j.cclet.2023.108542
-
[14]
Ce Liang , Qiuhui Sun , Adel Al-Salihy , Mengxin Chen , Ping Xu . Recent advances in crystal phase induced surface-enhanced Raman scattering. Chinese Chemical Letters, 2024, 35(9): 109306-. doi: 10.1016/j.cclet.2023.109306
-
[15]
Xiumei LI , Yanju HUANG , Bo LIU , Yaru PAN . Syntheses, crystal structures, and quantum chemistry calculation of two Ni(Ⅱ) coordination polymers. Chinese Journal of Inorganic Chemistry, 2024, 40(10): 2031-2039. doi: 10.11862/CJIC.20240109
-
[16]
Xiumei LI , Linlin LI , Bo LIU , Yaru PAN . Syntheses, crystal structures, and characterizations of two cadmium(Ⅱ) coordination polymers. Chinese Journal of Inorganic Chemistry, 2025, 41(3): 613-623. doi: 10.11862/CJIC.20240273
-
[17]
Chen Chen , Jinzhou Zheng , Chaoqin Chu , Qinkun Xiao , Chaozheng He , Xi Fu . An effective method for generating crystal structures based on the variational autoencoder and the diffusion model. Chinese Chemical Letters, 2025, 36(4): 109739-. doi: 10.1016/j.cclet.2024.109739
-
[18]
Tian Feng , Yun-Ling Gao , Di Hu , Ke-Yu Yuan , Shu-Yi Gu , Yao-Hua Gu , Si-Yu Yu , Jun Xiong , Yu-Qi Feng , Jie Wang , Bi-Feng Yuan . Chronic sleep deprivation induces alterations in DNA and RNA modifications by liquid chromatography-mass spectrometry analysis. Chinese Chemical Letters, 2024, 35(8): 109259-. doi: 10.1016/j.cclet.2023.109259
-
[19]
Haoyang Wang , Ronghao Zhang , Yanlun Ren , Li Zhang . A convenient method for measuring gas-liquid volumetric mass transfer coefficient in micro reactors. Chinese Chemical Letters, 2024, 35(4): 108833-. doi: 10.1016/j.cclet.2023.108833
-
[20]
Wangyan Hu , Ke Li , Xiangnan Dou , Ning Li , Xiayan Wang . Nano-sized stationary phase packings retained by single-particle frit for microchip liquid chromatography. Chinese Chemical Letters, 2024, 35(4): 108806-. doi: 10.1016/j.cclet.2023.108806
-
[1]
Metrics
- PDF Downloads(0)
- Abstract views(690)
- HTML views(16)