Nano-MOFs

Due to the highly ordered structures of MOFs, pores of specific sizes and shapes can be purposely constructed and used as nano-reactors for size-selective reactions. Li and coworkers synthesized a 3D MOF [Co3(bpdc)3(bpy)]-4DMF H20 (8, bpdc biphenyldicarboxylate, bpy 4,4 -bipyridine) by a solvothermal reaction of 1-D polymer [Co(bpdc)(H20)2] H20 and 4,4 -bipyridine [30]. The resulting twofold interpenetrating 3D porous framework (Fig. 10) showed great thermal stability. The... 

Nitrates. Thermodynamic parameters (AH=114kJmor AS = 62 J moF K ) for reaction (16) in NaNOs-KNOa eutectic melt have been determined (500— 700 K). Corresponding data (AH = 95 kJ moF AS = 84 J moF K ) for reaction (17) have also been calculated. Physicochemical analyses have been carried out on NaNOa-KNOs, Ca(N0a)2-Sr(N03)2, Sr(NOa)2-Ba(NOa)2" binary systems (generally as part of a quaternary reciprocal system), and LiNOa-RbNOa-CsNOa and LiN0a-KN03-Sr(N0a)2 ternary systems. 

As shown in Fig. 2.19, the nan(x asting pathway is also powerful to produce nano-porous carbons with remaikably high surface areas (up to 4,000 m g ) and precisely controlled microporous structures (0.5-1.5 mn) that are well suitable for CO2 capture [97]. The efforts to construct such molecular-sieve-type porous carbon using well-crystalline zeolite or MOFs-related materials (ZIFs, MOCPs) as sacrificial templates still continue. 

Juan-Alcaniz 1, Ramos-Fernandez EV, K teijn F, Gascon J. MOFs as nano-reactors. In Llabrds i Xamena FX, Gascon J, editors. Metal organic frameworks as heterogeneous catalysts. Cambridge The Royal Society of Chemistry 2013. p. 310-43. 

X. Xu, R. Cao, S. Jeong, and J. Cho, Spindle-like Mesoporous a-Fe203 Anode Material Prepared from MOF Template for High-Rate Lithium Batteries, Nano Lett., 12 (2012), 4988-4991. 

In the broad context of feeing the MOF crystal functionalization and growth, the use of the sol-gel method would offer enormous advantage over other methods. The reason relies on the fine tunability of chemical, crystallographic, morphological, functional properties of sol-gel-based materials [30-32]. Sol-gel technology has been used to prepare oxide systems to form nano/microparticles [33-35], fibers [36-38], thin films [39-41], and monoliths [42-44]. The wide options of structures and compositions afford sol-gel-based materials to be applied to broad applications such as controlled release, catalysis. 

The synthesis of OD and ID nanoMOF crystals chiefly depends on the spatial and/or temporal control of MOF crystal growth and nucleation. These processes can be partially controlled by adapting classical methodologies generally used to obtain bulk MOFs (e.g., solvothermal synthesis). This requires tuning of one or more of the reaction conditions, including the solvent (a poor solvent is often needed), the MOF precimsors, base (if needed), temperature and time, to promote nucleation and slow down the crystal growth. For instance, Horcajada et al reported that the careful selection of solvents, temperatures and reaction times was the key factor to synthesize nano-MIL-88A, nano-MIL-89, and nano-MIL-53 crystals smaller than 200 nm. 

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