PAPERmaking! FROM THE PUBLISHERS OF PAPER TECHNOLOGY Volume 2, Number 1, 2016
B.V, Netherlands) according to standard method of ISO 2470-1 (2009). Opacity was also measured using the same instrument according to ISO 2471 (2008). Paper roughness is defined as the measurement of the extent to which the surface of the paper deviates from plane; it is measured by the rate of flow between the paper sample and another standard surface in contact with it. It was measured in ml/min by roughness tester (Bendtsen; model K531, Messmer Bunchel) according to ISO 8791-2 standard. Air permeance is the mean flow of air through unit area under unit air-pressure difference in unit time under specified conditions and it was measured in ml/min by the roughness tester according to ISO 5636 standard. Results and discussion Characterisation of titanium dioxide nanopigments Crystal and bond structures Figure 1 shows the XRD patterns of the prepared nano titanium oxide samples at various experimental conditions. In general, the XRD patterns show low intensity and relatively broad diffraction peaks. This might be due to the fact that the prepared materials are of very small size and tend to be amorphous. Figure 1a is the XRD pattern of titanium oxide sample prepared using hydrothermal method at 120°C. The diffraction peaks at 2 Θ of 25.30 o , 37.78 o , 47.88 o , 54.50 o and 63.32 o are ascribed to the crystallographic structure anatase phase (TiO 2 , JCPDS card #84-1286). No other phases could be detected in the pattern. It is worth mentioning that the samples prepared at higher temperature (140°C) gave a mixture phases. Figure 1b is the XRD pattern of the prepared sample using hydrothermal method at 100°C. The XRD pattern exhibits diffraction peaks at 2 Θ of 25.43 o , 27.51 o , 30.76 o , 36.10 o , 37.82 o , 48.00 o , 54.30 o , 63.04 o and 69.13 o , respectively. The presence of these diffraction peaks indicating that the deposited titanium dioxide pigment present in the form of mixed phases. The diffraction peaks can be assigned to mainly a mixture of anatase (TiO 2 , JCPDS card #84-1286) and brookite phases (TiO 2 , JCPDS card #72-0100) with the presence of traces of rutile phase (TiO 2 , JCPDS card #75- 1753). Figure 1c is the XRD pattern of the prepared sample using hydrolysis method. The XRD pattern exhibits diffraction peaks at 27.26 o , 36.14 o , 41.16 o , 43.79 o , 54.23 o , 56.30 o , 62.92 o and 68.67 o . All the diffraction peaks are assigned to rutile phase (TiO 2 , JCPDS card #75- 1753).
Fig. 1 X-ray diffraction patterns of TiO 2 nanopigment samples prepared by a hydrothermal method at 120°C b hydrothermal method at 100°C c hydrolysis method
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Article 3 – Titanium Coating Pigments
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