Ettringite via Mechanochemistry: A Green and Rapid Approach for Industrial Application.

Here, we report on a first mechanochemical synthesis of ettringite, an important cement hydrate phase. The mineral compound ettringite ([CaAl(OH)]·(SO)·26HO) occurs rarely in nature, but is common for cement-based materials. Ettringite has wide technical application in the ceramic and paper industry.

In Situ Investigations of Mechanochemical One-Pot Syntheses.

We present an in situ triple coupling of synchrotron X-ray diffraction with Raman spectroscopy, and thermography to study milling reactions in real time. This combination of methods allows a correlation of the structural evolution with temperature information. The temperature information is crucial for understanding both the thermodynamics and reaction kinetics.

Warming up for mechanosynthesis - temperature development in ball mills during synthesis.

We present a first direct measurement of the temperature during milling combined with in situ Raman spectroscopy monitoring. The data reveal a low temperature increase due to the mechanical impact and clear temperature increases as a consequence of the reaction heat. Based on the data, temperature rises as postulated in the magma plasma and hot spot theory can be excluded for soft matter milling syntheses.

Comparison of quantitative defect characterization using pulse-phase and lock-in thermography.

Using optical excitation sources for active thermography enables a contactless, remote, and non-destructive testing of materials and structures. Currently, two kinds of temporal excitation techniques have been established: pulse or flash excitation, using mostly flash lamps; and periodic or lock-in excitation, using halogen lamps, LED, or laser arrays. From the experimental point of view, both techniques have their advantages and disadvantages.