Synthesis and Characterication of Water-Soluble ..
Preparation of water soluble and biocompatible AIE …
Maibelin Rosales is Ph.D. candidate in Materials Science program of University of Chile. She works in the design and synthesis of oxide-metal nanomaterials with controlled morphology and structural dimensionality such as 0D, 1D, 2D and 3D, and photocatalytic studies of these nanomaterials. Before starting her Ph.D. program, she was researcher at Venezuelan Institute for Scientific Research, where developed research in nanomaterials with applications in fields as catalysis, photocatalysis and energy. Currently, she is researcher at Advanced Mining Technology Center associated to research lines for water treatment and desalination processes.
synthesis of biocompatible water-soluble ZnS ..
Zeolitic imidazolate frameworks (ZIFs), a subclass of metal-organic frameworks (MOFs), havebeen recently employed in various fields such as gas separation, catalysis, water purification anddrug delivery.1 Their high importance is due to their chemical and thermal stability in addition tothe flexibility of their design. ZIFs have been synthesized solvothermally or at room temperatureusing organic solvents (e.g. methanol, DMF) or pure water.2 The control of size and morphologyof crystals has been achieved using reverse microemulsion methods, microwave, ultrasoundassistedsyntheses and coordination modulation methods.1-3 Herein, we investigate a newsynthesis method where ZIF crystals are produced using the reaction-diffusion framework (RDF)in a gel medium at room temperature. The method is based on the diffusion of an outer solutionof the organic linker or mixed linkers into an agar gel containing the inner metal ions Zn(II)and/or Co(II) where a precipitation reaction takes place leading to the formation of the ZIFcrystals. A propagating supersaturation wave, initiated at the interface between the outer solutionand the gel matrix leads to a precipitation front endowed with a gradient of crystal sizes rangingbetween 100 nm and 55 μm along the same reaction tube. While the precipitation fronts of ZIF-8 and ZIF-67 travel the same distance for the same initial conditions, ZIF-8 crystals therein areconsistently smaller than the ZIF-67 crystals due to the disparity of their rate of nucleation andgrowth. The effects of temperature, the concentration of the reagents, and the thickness of thegel matrix on the growth of the ZIF crystals are investigated. We also show that by using RDF,we can envisage the formation mechanism of the ZIF crystals, which consists of the aggregationof ZIF nanospheres to form the ZIF-8 dodecahedrons. Moreover, using RDF the formation of asolid-solution ZIF via the incorporation of Co(II) and Zn(II) cations within the same frameworkis achieved in a controlled manner. Finally, we demonstrate that doping ZIF-8 by Co(II)enhances the photodegradation of methylene blue dye under visible light irradiation in theabsence of hydrogen peroxide.