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Starch is used as porosity generator in membranes and other porous ceramics. There are different providers that offer a wide variety of starches, which produce distinct pore size distributions. A study was conducted to evaluate the effects of the characteristics of starches (impurities, particle size), obtained from potato, pea, maize and wheat, on the properties of microfiltration membranes formulated with traditional raw materials (the ceramic matrix was composed of quartz, albite and mullite). The results indicated that the pore size distribution and the permeability coefficient of the membrane can be controlled modifying only the particle size of starch. In this way, correlations were obtained between surface mean diameter of starch and membrane properties (characteristic pore diameters d 16 and d 50 , and permeability coefficient). Moreover, it is necessary to use a starch having a mean particle size greater than about 50 microns in order to obtain a significant change in the pore size distribution and an increase in the permeability of the membrane.

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A significant contribution to the reduction of the Urban Heat Island effect and cooling energy demand is given today by the so called cool materials for the building envelope with enhanced reflecting and emitting properties. The present study shows some preliminary results of the EU project COOL-Coverings aiming at developing innovative nanobased coatings with improved Near InfraRed reflecting capabilities. The key idea is to work on a nanoscale by tuning the crystal size and distribution of selected nanostructured oxides . Cool prototypes of brown colored ceramic tiles and green acrylic paints have been developed and compared to conventional ones showing an improvement in solar reflectance without any perceptual difference in color. The material characterization has been based on the measurement of spectral reflectance on a wide wavelength range (300-2200nm) using a UV/Vis/NIR spectrophotometer. In parallel with the development of nanostructured cool materials, natural aging tests on ceramic and painted concrete tiles have been performed with the goal of identifying and measuring the effects of the main aging factors affecting reflective properties. A significant drop of solar reflectance for paints has been noticed from the very beginning of the testing period while ceramic tiles have confirmed excellent resistance to weathering. However, both for paints and tiles the effect of soiling cannot be neglected and, if combined to weathering, it can lead to a solar reflectance reduction as high as 10%. This preliminary study will pave the way to a future development of dedicated accelerated aging testing procedures for cool materials.

Devitrification of a frit (glass) based on the oxide system SiO 2 -Al 2 O 3 -ZnO-CaO was studied. The following major crystalline phases were identified: gahnite (ZnAl 2 O 4 ), willemite (Zn 2 SiO 4 ), and a solid solution exhibiting an anorthite structure. A kinetic model was used to fit the experimental results. The model was derived by assuming that a precursor phase with an anorthite crystalline structure devitrified first and subsequently decomposed to form gahnite, while willemite crystallized independently. The proposed model satisfactorily reproduced the amount of gahnite, willemite, and anorthitetype crystals that formed during firing. The equations developed allowed the prediction of the anorthite structure, gahnite, and willemite crystal volume fractions in the resulting glaze as a function of firing temperature and time.