金属有机框架材料玻璃化转变温度的节点金属混合效应  

Node Metal Mixing Effect on Glass Transition Temperature of Metal–Organic Framework Materials

作　　者：杜子娟 葛璇 乔昂 师彩娟 杜涛 岳远征[3] 陶海征[1] DU Zjuan;GE Xuan;QIAO Ang;SHI Cajuan;DU Tao;YUE Yuanzheng;TAO Haizheng(State Key Laboratory of Silicate Materials for Architectures,Wuhan University of Technology,Wuhan 430070,China;School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai Key Laboratory of Materials Laser Processing and Modification,Shanghai 200240,China;Department of Chemistry and Bioscience,Aalborg University,Aalborg DK-9220,Denmark;Wuhan University of Technology Advanced Engineering Technology Research Institute of Zhongshan City,Zhongshan 528437,Guangdong,China;Beijing Synchrotron Radiation Facility,Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]武汉理工大学,硅酸盐建筑材料国家重点实验室,武汉430070 [2]上海交通大学材料科学与工程学院,上海市激光制造与材料改性重点实验室,上海200240 [3]奥尔堡大学化学与生物科学系,奥尔堡DK-9220,丹麦 [4]中山市武汉理工大学先进工程技术研究院,广东中山528400 [5]中国科学院高能物理研究所,北京同步辐射装置,北京100049

出　　处：《硅酸盐学报》2024年第12期3673-3684,共12页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(22175135);广东省基础与应用基础研究基金自然科学基金项目(2022A1515010312)。

摘　　要：作为金属有机框架玻璃的子集,沸石咪唑酯骨架(ZIF)玻璃结构上由配位键所主导,具有高玻璃形成能力等一系列独特的性能。金属离子的替代会显著影响该类材料的功能,使玻璃化转变温度(T_(g))等性质随替代金属节点离子浓度的线性改变呈现出非线性的变化规律,即混合金属节点效应。通过对比Zn_(1–x)Co_(x)(C_(3)H_(3)N_(2))2(Zn_(1–x)Co_(x)-ZIF-4)高密度非晶相(HDA)和Zn_(1–x)Co_(x)(C_(3)H_(3)N_(2))1.75(C_(7)H_(5)N_(2))0.25(Zn_(1–x)Co_(x)-ZIF-62)熔融淬冷玻璃(MQG)的Tg,发现拥有混合配体的Zn_(1–x)Co_(x)-ZIF-62 MQG的Tg均高于拥有单一配体的Zn_(1–x)Co_(x)-ZIF-4 HDA的T_(g)。通过混合金属节点效应强度[(ΔT_(g))_(max)]的对比,发现与单配体Zn_(1–x)Co_(x)-ZIF-4玻璃相比,混合配体Zn_(1–x)Co_(x)-ZIF-62玻璃中(ΔT_(g))_(max)更高。基于拓扑束缚理论和化学键特性,同时结合全散射实验对分布函数和配位四面体结构参数计算,本工作解析了Zn_(1–x)Co_(x)-ZIF-4和Zn_(1–x)Co_(x)-ZIF-62玻璃化转变温度和混合金属节点效应强度出现差异的结构和化学起源。Introduction Zeolitic imidazolate framework(ZIF)material is a subset of metal-organic framework(MOF)materials with a structure similar to zeolite.Its basic structural unit is the[MN_4]tetrahedron formed by the coordination bond between transition metal center ions M(Co,Zn,etc.)and imidazole anions(Im,C_(3)H_(3)N_(2)^(–))and their derivatives.Among them,ZIF-62[Zn(C_(3)H_(3)N_(2))_(2)–_n(C_(7)H_(5)N_(2))_(n)]and ZIF-4[Zn(C_(3)H_(3)N_(2))_2]crystals can melt and form glasses before decomposition,which are widely used as basic research objects for MOF vitrification.For ZIF-62 and ZIF-4 glasses,changes in metal nodes can cause changes in the local coordination structure,including bond length and tetrahedral symmetry.This could further result in non-linear variations in properties such as glass transition temperature(T_(g)),which is known as a mixed-metal node effect.The impact of the coexistence of mixed ligands and metal nodes in ZIF structure on thermal properties and their structural origins is not elucidated.Therefore,a further exploration of the node metal mixing effect in ZIF glasses and its dependence on the ligand composition and structure can provide some insights into the relationship between the structure and performances of multi-component ZIF glasses.It is also of great significance to clarify the mixed former effect in inorganic glass and develop novel functional MOF glasses.In this study,the effect of ligand changes on the central metal node content and T_(g)of ZIF-4 and ZIF-62 glasses were discussed.In addition,the structural origin about the difference in mixed-metal node effect strength[(ΔT_(g))_(max)]between ZIF-4 glass and ZIF-62 glass was also analyzed.Methods ZIF-4/62 crystals and ZIF-4/62 melt-quenched glass(MQG)were prepared by solvothermal and melt-quenching methods,respectively.The Zn_(1–x)Co_(x)-ZIF-4 high-density amorphous phase(HDA)was prepared by differential scanning calorimetry instruments.The cobalt contents of bimetallic ZIF-4 samples were characterized by inductively coupled p

关 键 词：沸石咪唑酯骨架玻璃 配位四面体 混合金属节点效应 玻璃化转变温度 配体 

分 类 号：TQ641[化学工程—精细化工]