Preparation of Layered Intercalation Compounds Via One-Pot in Situ Synthesis
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Layered materials, such as layered silicates, layered phosphates, layered double hydroxides, and metal chalcogenides, have attracted highresearch interest in the past few decades. Layered materials have been widely used in our daily life, such as batteries, catalysts, medical devices, waste treatment, and lubricants. A wide range of chemicals, including small molecules, oligomers, polymers, biomolecules, and ions, have been intercalated into layered materials for new or enhanced properties. Various approaches have been developed to achieve intercalation were reviewed in this thesis. Nanostructured organic-inorganic hybrid materials, including polymer nanocomposites, layer-by-layer assembled thin films, have been extensively investigated over the past two decades and have found wide applications owing to their excellent performance. Either regular polymer nanocomposites or layer-by-layer assembled thin films are typically prepared using pre-synthesized nanofillers/nanoplatelets. Here, we report a new approach to prepare nanostructured hybrid materials via in situ synthesis of nanoplatelets within the polymer/monomer matrix. Alpha-zirconium phosphate (ZrP) was synthesized in a solution system containing a polymer (such as polyethylene glycol, PEG) or monomer (such as acrylamide). In the case of polymer in situ synthesis, during the synthesis of ZrP, PEG chains were embedded into the ZrP interlayer space, leading to a larger interlayer distance, which is similar to the intercalated layered compound. Proper formulation ratio proved to be critical to avoid forming pristine ZrP, and avoid interfering the growth of the layered structure of ZrP. It has also been found that longer polymer chains are desirable for minimizing the formation of pristine ZrP, but would not affect the interlayer distance. All the PEG chains are perfectly parallel to the layer planes. Besides polymers, monomer molecules (such as acrylamide) have also been successfully embedded into the interlayer space to form an intercalated structure during in situ synthesis. The monomer molecules were further polymerized in the ZrP layer galleries. As a result, the inorganic/organic hybrid intercalation compound was synthesized without pre-form either layered host materials or guest species.