(48i) In-Situ Preparation of Nano-Portland Cement Via Flame Spray Pyrolysis: Processing, Characterization and Mechanical Properties

Due to their mechanical properties and the versatile fields of application cementitious materials belong to the most widely used construction materials. In the last processing step in the multi-step commercial cement production the clinker is ground in order to generate a reactive product. The final grain size influences both setting speed and mechanical strength progression of the cured cement. In this work, nanoparticles with a typical Portland cement composition (68% CaO, 22% SiO2, 6% Al2O3, 4% Fe2O3) were produced in a one-step preparation route. Flame spray pyrolysis (FSP) has been established as a reliable production process for mixed oxide nanoparticles of high phase homogeneity [1,2]. The continuous high temperature gas process uses suitable organic derivatives of the desired metals as homogeneous mixtures. The precursors are directly sprayed into a flame where they are rapidly converted into the corresponding mixed oxides.

The in-situ prepared Portland cement nanoparticles were characterized with respect to particle size, crystal phases, and morphology. Pills were cured by the addition of water. The reactivity of the particles, the phase composition and the mechanical properties of the cured cement were compared to commercially available Portland cement.

References: [1] L. Maedler, W.J. Stark, S.E. Pratsinis, J. Mat. Res., 17 1356 (2002), [2] W.J. Stark, M. Maciejewski, L. Mädler, S.E. Pratsinis, and A. Baiker, J. Catal. 220 (1) 35-43 (2003); W.J. Stark, L. Maedler, S.E. Pratsinis, Flame Made Metal Oxides WO 2004/005184 (2002)