Polymerization of Alkylsilanes on ZIF-8 to Hierarchical Siloxane Microspheres and Microflowers

Abstract

Abstract:The use of metal-organic frameworks (MOFs) in the polymerization field remains comparatively rare up to now, let alone studies on the fabrication of polymer microstructures through a MOFs-catalyzed assembly process. Zeolitic imidazolate framework-8 (ZIF-8), a well-known MOF for its chemical and thermal stabilities, was used to induce a polymerization reaction of saturated alkylsilanes for the first time. The reaction temperature was found to be critical for morphology control of the polymerized ZIF-siloxane composites. The polymerization of alkylsilanes by ZIF-8 at room temperature resulted in siloxane microspheres while rose petal-like microstructures were obtained at higher temperature. The effects of the reaction time on the structures of the polymerization products were also investigated and the polymerization reaction process was proposed. This work expands the field of MOFs' applications and develops a reasonable method for the multidimensional assembly of MOFs building blocks into required structures or platforms for designing new kinds of hierarchical morphologies, which to our knowledge has not been previously investigated.

High Molecular Weight Poly(methyl methacrylate) Synthesis Using Recyclable and Reusable Zeolitic Imidazole Framework‐8 Catalyst

“…[51] The pure phase structure of ZIF-8 was characterized using various techniques (powder X-ray diffraction (PXRD), scanning electron microscope (SEM), thermogravimetric analysis (TGA), FTIR as well as nitrogen physisorption) where the results found were in good agreement with reported studies (Figures S1-S6, Supporting Information). [50][51][52][53] Among these techniques, PXRD patterns of ZIF-8 displays a clear indication of the crystalline nature where the peak positions (011, 002, 112, 022, 013, 222) confirming the sodalite structure of ZIF-8 ( Figure S1, Supporting Information). [51,52] Besides, the characteristics absorption peak at 421 cm −1 in the FTIR spectrum is assigned to the stretching mode of Zn-N metal-organic nature in ZIF-8, and the other signals confirmed the formation of ZIF-8 ( Figure S4, Supporting Information).…”

“…[ 46–48 ] The zeolitic imidazole framework‐8 (ZIF‐8) contains not only the acid sites (Zn atoms) but also the base sites (N in imidazole) in its structure as like Lewis pairs suggesting to be a promising catalyst for polymerization and some MOFs are reported as MMA polymerization catalysts. [ 41,45,49,50 ] Herein, we demonstrate the catalytic activity of ZIF‐8 in MMA polymerization. In contrast to other heterogeneous catalysts, HMWP (PMMA) is obtained using ZIF‐8 as a simple and recyclable catalyst without any co‐catalyst in the absence of solvents.…”

Metal–Organic Framework Thin Films on High-Curvature Nanostructures Toward Tandem Electrocatalysis

“…ZIF-8 (Zn­(MeIM) 2 , MeIM = 2-methylimidazole) was selected for its high chemical and thermal stability (>500 °C) and large pore size (11.6 Å). , ZIF-8 has been explored for a range of catalytic applications, , including CO oxidation with embedded gold nanoparticles …”

“…Tunable rare-earth fcu MOFs (Re- fcu -MOF) are a class of MOFs composed of [RE 6 (μ 3 -OH) 8 (O 2 C−) 12 ] hexanuclear MBBs (MBB = molecular building block) bridged by a ditopic ligand, where the carbon atoms of the coordinated carboxylates act as points of extension. This RE- fcu -MOF is highly thermally stable up to 500 °C and chemically stable in water, acidic, and basic conditions . The fcu -MOF platform has been explored mostly for its molecular sieving capabilities and hydrocarbon separations and has not previously been investigated for electrocatalysis. , …”

“…This RE-fcu-MOF is highly thermally stable up to 500 °C and chemically stable in water, acidic, and basic conditions. 34 The fcu-MOF platform has been explored mostly for its molecular sieving capabilities and hydrocarbon separations and has not previously been investigated for electrocatalysis. 37,38 Al 2 (OH) 2 TCPP has porphyrin molecular units and was shown to be hydrolytically stable and thermally stable up to 400 °C.…”