THESIS
2018
xix, 148 pages : illustrations ; 30 cm
Abstract
Microfluidics systems could facilitate the discovery of synthetic routes as well as help the
understanding of possible mechanisms for the reactions or processes. Flow synthesis of particles
in microfluidics systems could generate products with more stable quality than batch synthesis.
The organic reactions in microfluidics systems could be faster, cleaner and safer. Metal-organic
frameworks (MOFs) are attracting increasingly more attention for their appealing properties of gas
separation, adsorption, catalysis, and sensing. This work investigates the formation of MOFs
materials in microfluidics systems as well as the application of MOFs in microfluidics systems for
catalysis.
The ultrafast syntheses of ZIF-8 rhombic dodecahedra particles, CuBDC nanosheets and
magnetic ZIF-8 in...[
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Microfluidics systems could facilitate the discovery of synthetic routes as well as help the
understanding of possible mechanisms for the reactions or processes. Flow synthesis of particles
in microfluidics systems could generate products with more stable quality than batch synthesis.
The organic reactions in microfluidics systems could be faster, cleaner and safer. Metal-organic
frameworks (MOFs) are attracting increasingly more attention for their appealing properties of gas
separation, adsorption, catalysis, and sensing. This work investigates the formation of MOFs
materials in microfluidics systems as well as the application of MOFs in microfluidics systems for
catalysis.
The ultrafast syntheses of ZIF-8 rhombic dodecahedra particles, CuBDC nanosheets and
magnetic ZIF-8 in microfluidics systems was studied. The impact of flow rate and flow patterns
on the particle size and morphology of the final products was discussed. It was found that the
Taylor flow pattern helped the formation of particles of homogeneous size, and generated larger
particles and higher yield than laminar flow. The time of magnetic ZIF-8 preparation was
shortened to 7.24 min and the adsorption ability is improved because of smaller grain size. The
immobilization of ZIF-8 on magnetic particles facilitate the downstream separation. It was found
that the Taylor flow is better than laminar flow or batch synthesis because its internal circulation
provides advantageous mixing conditions and loads more ZIF-8 particles.
The immobilization of MOFs such as ZIF-8, MIL-88b, HKUST-1 and MIL-101 on porous
support like glass fiber membrane and silica monolith was realized. The porous structure of the
supports could be regarded as microchannels for organic reactions, while the voids in the porous
structure is the conduits for organic reactions. It was found by using these kinds of microreactors, the yields of the Knoevenagel reaction, acetalization and epoxidation could be improved. The
selectivity of epoxidation is largely increased by using Taylor flow method in a HKUST-1/silica
monolith microreactor. Additionally, the fixed bed MOFs microreactors eliminated solid catalyst
separation and saved energy.
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