Silicon-29 multiple quantum filtered n.m.r. spectroscopic evidence for the presence of only six single site silicate anions in a concentrated potassium silicate solution

Potassium silicate is well known as a fertilizer and source of silica for plants growth. This study aims to infiltrate nitrogen from carbamide (urea) into potassium silicate solution to produced silica potassium nitrogen (Si-K-N) matrix by precipitation method using CO2 as precipitator. Potassium silicate in the range of 3-8% SiO2 was obtained by extracting silica from geothermal sludge using potassium hydroxide solution. Carbamide is added to the potassium silicate solution allowed by mixing and flowing of CO2 gas in reactor glass. The result of IR spectra indicated the presence of N-H groups, potassium and silica in the gel matrix produced from precipitation process while no N-H group appears in the gel matrix produced from precipitation in the absence of carbamide. X-ray fluorescence showed the composition of the product Si-K-N in the range of 40 to 50 %SiO2 and in the range of 50 to 60 %K2O.

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Materials Studio simulation for the adsorption properties of CO2 molecules at the surface of sodium silicate and potassium silicate solution under different pressure conditions

International Journal of Metalcasting ◽

10.1007/s40962-021-00589-5 ◽

2021 ◽

Author(s):

Haolong Liu ◽

Lai Song

Keyword(s):

Sodium Silicate ◽

Silicate Solution ◽

Adsorption Properties ◽

Potassium Silicate ◽

Potassium Silicate Solution ◽

Materials Studio

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ChemInform Abstract: A Two-Dimensional 29Si NMR Spectroscopic Study of the Structure of the Silicate Anions Present in an Aqueous Potassium Silicate Solution.

ChemInform ◽

10.1002/chin.198836011 ◽

1988 ◽

Vol 19 (36) ◽

Author(s):

C. T. G. KNIGHT

Keyword(s):

Spectroscopic Study ◽

Silicate Solution ◽

Potassium Silicate ◽

29Si Nmr ◽

Two Dimensional ◽

Potassium Silicate Solution

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Spectroscopic evidence for the excitonic lasing mechanism in ultraviolet ZnS/ZnCdS multiple quantum well lasers

Applied Physics Letters ◽

10.1063/1.116954 ◽

1996 ◽

Vol 69 (27) ◽

pp. 4230-4232 ◽

Cited By ~ 9

Author(s):

K. B. Ozanyan ◽

J. E. Nicholls ◽

M. O’Neill ◽

L. May ◽

J. H. C. Hogg ◽

...

Keyword(s):

Quantum Well ◽

Multiple Quantum Well ◽

Quantum Well Lasers ◽

Multiple Quantum ◽

Spectroscopic Evidence ◽

Lasing Mechanism

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Reactivity and Microstructure of Metakaolin Based Geopolymers: Effect of Fly Ash and Liquid/Solid Contents

Materials ◽

10.3390/ma12213485 ◽

2019 ◽

Vol 12 (21) ◽

pp. 3485 ◽

Cited By ~ 7

Author(s):

Vogt ◽

Ukrainczyk ◽

Ballschmiede ◽

Koenders

Keyword(s):

Mechanical Properties ◽

Fly Ash ◽

Isothermal Calorimetry ◽

Bound Water ◽

Silicate Solution ◽

X Ray Diffraction ◽

Solid Ratio ◽

Potassium Silicate Solution ◽

Dissolution Tests ◽

Strength Tests

Geopolymers are inorganic binders based on mixtures of an aluminosilicate powder with an alkali-silicate solution. Properties of geopolymers are strongly determined by the type of reactive solid, the liquid/solid ratio of paste and, amongst others, the Si/Al ratio of the formed geopolymer network. In this study, fly ash blended metakaolin based geopolymers with varying liquid/solid ratios (l/s), activated by potassium silicate solution, are investigated. Reactivity of metakaolin and fly ash was investigated by powder X-ray diffraction (XRD) and dissolution tests. Reactivity, mechanical properties and microstructure of hardened pastes were analyzed by setting and compressive strength tests, mercury intrusion porosimetry (MIP), capillary water absorption tests, thermogravimetric analysis-differential scanning calorimeter (TGA-DSC), isothermal calorimetry and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). The results show that substitution of metakaolin by fly ash as well as variation of l/s brings advantages up to a certain degree, but also has a considerable influence on the pore size distribution, mechanical properties, Si/Al ratio of the geopolymer network and the content of bound water.

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Characterisation of multilayer materials using a position-sensitive atom probe

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100176253 ◽

1990 ◽

Vol 48 (4) ◽

pp. 624-625

Author(s):

RAD Mackenzie ◽

G D W Smith ◽

A. Cerezo ◽

J A Liddle ◽

CRM Grovenor ◽

...

Keyword(s):

Quantum Well ◽

Quantum Wells ◽

Spatial Information ◽

Chemical Vapour ◽

Atom Probe ◽

Organic Chemical ◽

Growth Stages ◽

Multiple Quantum ◽

Quartz Wool ◽

Position Sensitive

The position sensitive atom probe (POSAP), described briefly elsewhere in these proceedings, permits both chemical and spatial information in three dimensions to be recorded from a small volume of material. This technique is particularly applicable to situations where there are fine scale variations in composition present in the material under investigation. We report the application of the POSAP to the characterisation of semiconductor multiple quantum wells and metallic multilayers.The application of devices prepared from quantum well materials depends on the ability to accurately control both the quantum well composition and the quality of the interfaces between the well and barrier layers. A series of metal organic chemical vapour deposition (MOCVD) grown GaInAs-InP quantum wells were examined after being prepared under three different growth conditions. These samples were observed using the POSAP in order to study both the composition of the wells and the interface morphology. The first set of wells examined were prepared in a conventional reactor to which a quartz wool baffle had been added to promote gas intermixing. The effect of this was to hold a volume of gas within the chamber between growth stages, leading to a structure where the wells had a composition of GalnAsP lattice matched to the InP barriers, and where the interfaces were very indistinct. A POSAP image showing a well in this sample is shown in figure 1. The second set of wells were grown in the same reactor but with the quartz wool baffle removed. This set of wells were much better defined, as can be seen in figure 2, and the wells were much closer to the intended composition, but still with measurable levels of phosphorus. The final set of wells examined were prepared in a reactor where the design had the effect of minimizing the recirculating volume of gas. In this case there was again further improvement in the well quality. It also appears that the left hand side of the well in figure 2 is more abrupt than the right hand side, indicating that the switchover at this interface from barrier to well growth is more abrupt than the switchover at the other interface.

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