Silver-exchanged zeolites and clays are used in polymer composites to confer broad-spectrum antimicrobial properties on a range of functional materials. Tobermorite is a layer lattice mineral whose potential as a carrier for Ag ions in antibacterial composites has not yet been investigated. Accordingly, in this study, synthetic tobermorite was ion-exchanged with 10 wt% silver ions and the resul...

Hydrothermal formation reaction of tobermorite in the autoclaved aerated concrete (AAC) process has been investigated by in-situ X-ray diffraction. High-energy X-rays from a synchrotron radiation source in combination with a newly developed autoclave cell and a photon-counting pixel array detector were used. XRD measurements were conducted in a temperature range of 100–190 °C throughout 12 h of...

The crystal structure of a natural tobermorite from Zeilberg, Maroldsweisach, Germany (average formula Ca2.2s[Si307.s(OH)1.5]'1 H20), is solved using the data obtained from an automatic diffractometer. For the structure determination only the sharp main reflexions are considered. The crystal data of the chosen subcell are: a' = 5.586(4) A, b' = 1696(2) A, C = 22.779(7) A, S.G. Imm2, V = 470.25 ...

Tobermorite was synthesized successfully from the ash, which was produced and detoxified from asbesto-containing disaster waste in great east Japan earth quake, by alkali hydrothermal treatment. Tobermorite synthesis was examined as a function of reaction temperature and NaOH concentration. The formation of tobermorite was identified in the product treated with 1-4 M NaOH solution at 130 and 18...

Most of calcium silicate hydrate or calcium aluminosilicate hydrate, CS(A)H, and related phases are relevant to Cement industry and have potential as geothermal well sealants as well as autoclaved construction materials. The CS(A)H system is highly complex and is comprised of crystalline to amorphous phases with variable composition that build up a wide family of phases, which are interesting f...

Understanding the integrity of well-bore systems that are lined with Portland-based cements is critical to the successful storage of sequestered CO2 in gas and oil reservoirs. As a first step, we investigate reaction rates and mechanistic pathways for cement mineral growth in the absence of CO2 by coupling water chemistry with XRD and NMR spectroscopic data. We find that semi-crystalline calciu...

The structural evolution of nanocrystalline calcium silicate hydrate (C-S-H) as a function of its calcium to silicon (Ca/Si) ratio has been probed using qualitative and quantitative X-ray atomic pair distribution function analysis of synchrotron X-ray scattering data. Whatever the Ca/Si ratio, the C-S-H structure is similar to that of tobermorite. When the Ca/Si ratio increases from ∼0.6 to ∼1....

The structure and solubility of hydrothermally prepared 11 Å Al-tobermorite with Al/(Al + Si) = 0.1 has been studied. NMR FTIR data indicated the formation a cross-linked, well crystalline preferential uptake Al in branching sites silicate chains. incorporation tobermorite increased basal spacing by ~0.18 Å. Solubility experiments little effect temperature on weak stabilization regard to toberm...