Controllable Synthesis And Properties Of Rare Earth Based Nano Metal-Organic Frameworks

Metal organic framework(MOF) is a type of material that is composed of metal ions or clusters that are connected through polytopic organic ligands. The extension as well as the reliability of structure-related applications of MOFs requires not only scalable but also effective morphology tunable products. This thesis is focused on the synthesis and fluorescent applications of {[Eu2(MFDA)2(HCOO)2(H2O)6]·H2O}n(H2MFDA=9,9-dimethyl fluorene-2,7-dicarboxylic acid) and Tb BTC(H3BTC=benzene-1,3,5-tricarboxylic acid) nanostructures. The contents are as follows.1. The morphology uniformity of the nanocrystals is a thorny problem in the chemical solution synthetic systems, where involves an associated interactions of the reactants, solvents, auxiliary agents, and temperature, always tend to get products with mixed morphologies or phases. A surfactant and substrate synergetic chemical solution technique was promoted to synthesize uniform shaped MOF nanodisks. The hexaprism nanodisks of {[Eu2(MFDA)2(HCOO)2(H2O)6]·H2O}n(Eu-MFDA HND_dh, H2MFDA=9,9-dimethyl fluorene-2,7-dicarboxylic acid) were obtained on a supported substrate in the presence of sodium dodecyl sulfate. The surfactant plays an important role in miniaturizing the size and scissoring the morphology to nanoparticles or defected HND, whereas the supporting substrate can help the further fusion and thus effectively promote the formation of well- shaped Eu-MFDA HND_dh.2. The Eu-MFDA hexaprism nanodisks(Eu-MFDA HND) have good photoluminescence. The dehydrated Eu-MFDA HND crystals showed a much higher fluorescent quenching efficiency towards 2,4-DNT as compared to its corresponding bulk crystal. It also showed an obvious response towards PA、1,4-DNB、2,6-DNT、2-NT、4-NT、2,4-DNT、1,3-DNB、DMNB and NM with the quenching efficiencies of 93%、66%、52%、43%、43%、42%、38%、17% and 8%, respectively(5×10-4 M). The Eu-MFDA HN D can be filtered onto a piece of organic filter paper to make a nano MOF-film based test strip. This test based on film is convenient and quickly.3. Tb BTC nanocrystals of nanowires were successfully fabricated using H3 BTC and Tb(NO3)3·6H2O in the liquid phase. Surfactants and temperature played a role of tailoring the size and morphology in the reaction. The obtained Tb BTC nanocrystals can be utilized as a sensitive materials for explosive molecules.