Inorganic aluminosilicate polymers

J. Brus, L. Kobera, M. Urbanova, D. Kolousek, J. Kotek, Insights into the structural transformations of aluminosilicate inorganic polymers a comprehensive solid-state NMR study. J. Phys. Chem. C 116 (2012) 14627-14637. 

K.J.D. MacKenzie and M.J. Bolton, Electrical and Mechanical Properties of Aluminosilicate Inorganic Polymer Composites with Carbon Nanotubes. J. Mat. Sci., (Submitted). 

The slow reaction process is likely due to multiple factors including (I) hindered reaction kinetics and diffusivity within the viscous gel, (2) inadequate or sluggish dissolution of precursor powder, and (3) a limited potential of iron to form a potassium-based aluminosilicate inorganic polymer. Hematite is not expected to be very soluble in concentrated alkali hydroxide solution, although it dissolution is dependent on the alkali used such that solubility is highest in NaOH, followed by KOH and LiOH. It is expected that as maghemite, magnetite and hematite dissolve, Fe and Fe ions would be released and would then be free to interact with the silica gel. Iron is versatile and can exist in multiple oxidation and coordination states in the final material. In zeolite systems, the more dilute conditions favors the diffusion of iron and other species, and a more thermodynamically stable state can be reached. The use of water-soluble iron sources such as iron nitrate and potassium ferrate in hydrothermal conditions have been shown to be an effective way to produce iron zeolites in which iron is located in tetrahedral coordination. ... 

Zeolites. Zeolites are crystalline inorganic polymers made of aluminosilicates and have open framework structures. Natural zeolites (faujasites) have pores of sufficient size to be useful in petroleum refining. Synthetic faujasite-type zeolites are now available in large commercial quantities and have become an important catalyst in the petroleum industry. Comprehensive reviews on the application of zeolite catalysis are available (ll lS). 

Zeolites are crystalline, micro-porous, hydrated aluminosilicates that are built from an infinitely extending three-dimensional network of [SiOJ and [AlOJ " tetra-hedra linked to each other by the sharing of the oxygen atom. Generally, their structure can be considered as inorganic polymer built from tetrahedral TO4 units, where T is Sb+ or AP+ ion. Each oxygen (O) atom is shared between two T atoms. 

Inorganic polymers, also known as geopolymers, are aluminosilicates, conventionally prepared by condensation of a solid aluminosilicate such as the dehydroxylated clay mineral metakaolinite with an alkali silicate solution under highly alkaline conditions. At ambient temperatures these materials set and harden to an X-ray amorphous product containing solely tetrahedral A1 and tetrahedral Si characterised by a broad Si MAS NMR resonance at about -92 ppm. The most recent Na MAS NMR studies have provided more details about the way in which the charge-balancing alkali ions are incorporated in the structure. 

The wide assortment of polymer systans (polypropylene, poly(methyl methacrylate) [PMMA], polyepoxide, polystyrol, PC, etc.) is used as a polymeric matrix for nanocomposites production (Ray and Okamoto 2003). The most well-known fillers of polymeric matrix are nanoparticles (silica, metal, and other organic and inorganic particles), layered materials (graphite, layered aluminosilicates, and other layered minerals), and fibrous materials (nanofibers and nanotubes) (Thostenson et al. 2005). Nanocomposite polymer materials containing metal or metal oxide particles attract growing interest due to their specific combination of physical and electric properties (Rozenberg and Tenne 2008, Zezin et al. 2010). Nanocomposites on the base of layered materials... 

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