Interpretation of X-ray Powder Diffraction Patterns . By H. Lipson and H. Steeple. Pp. viii + 335 + 3 plates. (Mac-millan: London; St Martins Press: New York, May 1970.) £4.

X-Ray Diffraction

The Hydrothermal Synthesis of Zeolites: History and Development from the Earliest Days to the Present Time

The hydrothermal synthesis of zeolites: precursors, intermediates and reaction mechanism

In the past decade or so, small-pore zeolites have received greater attention than large- and medium-pore molecular sieves that have historically dominated the literature. This is primarily due to the commercialization of two major catalytic processes, NOx exhaust removal and methanol conversion to light olefins, that take advantage of the properties of these materials with smaller apertures. Small-pore zeolites possess pores that are constructed of eight tetrahedral atoms (Si4+ and Al3+), each time linked by a shared oxygen These eight-member ring pores (8MR) provide small molecules access to the intracrystalline void space, e.g., to NOx during car exhaust cleaning (NOx removal) or to methanol en route to its conversion into light olefins, while restricting larger molecule entrance and departure that is critical to overall catalyst performance. In total, there are forty-four structurally different small-pore zeolites. Forty-one of these zeolites can be synthesized, and the first synthetic zeolite (KFI, 1...

Small-Pore Zeolites: Synthesis and Catalysis

With more than a hundred elements in the periodic table, a large number of potential new materials exist to address the technological and societal challenges we face today; however, without some guidance, searching through this vast combinatorial space is frustratingly slow and expensive, especially for materials strongly influenced by processing. We train a machine learning (ML) model on previously reported observations, parameters from physiochemical theories, and make it synthesis method–dependent to guide high-throughput (HiTp) experiments to find a new system of metallic glasses in the Co-V-Zr ternary. Experimental observations are in good agreement with the predictions of the model, but there are quantitative discrepancies in the precise compositions predicted. We use these discrepancies to retrain the ML model. The refined model has significantly improved accuracy not only for the Co-V-Zr system but also across all other available validation data. We then use the refined model to guide the discovery of metallic glasses in two additional previously unreported ternaries. Although our approach of iterative use of ML and HiTp experiments has guided us to rapid discovery of three new glass-forming systems, it has also provided us with a quantitatively accurate, synthesis method–sensitive predictor for metallic glasses that improves performance with use and thus promises to greatly accelerate discovery of many new metallic glasses. We believe that this discovery paradigm is applicable to a wider range of materials and should prove equally powerful for other materials and properties that are synthesis path–dependent and that current physiochemical theories find challenging to predict.

Accelerated discovery of metallic glasses through iteration of machine learning and high-throughput experiments

The experimental conditions were optimized for the synthesis of amorphous SiO2 particles by the reaction of neutralization of sodium silicate solution with H2SO4 solution Amorphous SiO2 particles were characterized by XRD, FT-IR, FE-SEM, EDS and microelectrophoresis The amorphous peak was located at 2θ = 218o in the XRD pattern Primary SiO2 particles were ~ 15 to ~ 30 nm in size and they aggregated into bigger particles Amorphous SiO2 particles showed a specific surface area up to 130 m2g-1, dependent on the parameters of the precipitation process The EDS spectrum of amorphous SiO2 particles did not show contamination with sulfate or other ions, which cannot be excluded in traces pHzpc =17 was obtained by microelectrophoresis

/pdf/precipitation-of-amorphous-sio2-particles-and-their-1bsrlczlbb.pdf

Precipitation of amorphous SiO2 particles and their properties

Interaction of surfactant-modified zeolites and phosphate accumulating bacteria

https://bib.irb.hr/datoteka/380885.colloid_2009.pdf

Sorption phenomena of modification of clinoptilolite tuffs by surfactant cations.

Kinetic study of the transformation of zeolite A into zeolite P

https://bib.irb.hr/datoteka/488418.CLAY2044.pdf

Lavoslav Sekovanić

Papers

Precipitation of amorphous SiO2 particles and their properties

Interaction of surfactant-modified zeolites and phosphate accumulating bacteria

Sorption phenomena of modification of clinoptilolite tuffs by surfactant cations.

Kinetic study of the transformation of zeolite A into zeolite P

Sepiolite as carrier of the phosphate-accumulating bacteria Acinetobacter junii