A acidez da estrutura da zeólita ZSM-22 foi determinada por análise térmica. A energia de ativação, calculada pelo método de Ozawa, envolveu uma energia de termodecomposição de 18,44 kJ.mol-1. O valor do fator pré-exponencial A foi de 2,2746. Suas propriedades texturais foram determinadas por análise de dessorção/adsorção de nitrogênio, cujos resultados indicaram a existência de microporosidade, com área de superfície de 257 m².g-1, volume de microporos de 0,041 cm³.g-1 e diâmetro de poros de 32,6 Å. Análises de luminescência, utilizando európio como sonda, sugerem que a acidez é distribuída uniformemente dentro da estrutura da zeólita.

The acidity and stability of ZSM-22 zeolite structure have been studied by thermal analysis. The activation energy calculated by Ozawa method to the events related to thermodecomposition was 18.44 kJ.mol-1. The value of the pre-exponential factor A was 2.2746. Its textural properties have been determined by nitrogen adsorption desorption analysis, whose results indicated microporous properties, with surface area 257 m².g-1, micropore volume 0.041 cm³.g-1 and pore diameter 32.6 Å. Luminescence analyses, using europium as probe, suggest that the acidity is distributed uniformly within the zeolite structure.

Fe10Ag90 granular alloys have been fabricated, using a sol-gel method, for a range of nitric acid concentrations in the start solution. The samples have been characterized by X-ray diffraction and magnetization measurements. The average Fe particle sizes derived from X-ray diffraction are in the range 24-29 nm, indicating a large variation. The coercivity obtained from the hysteresis curve is two orders of magnitude larger that of pure iron in all the samples. Moreover, the hysteresis curves do not saturate, even in fields of up to 1 T. These observations indicate that the samples contain both superparamagnetic and blocked particles. A comparison between the coercive field and the average particle diameter, determined by the Sherrer's formula, is displayed in all acid concentrations.

Progress is reported towards the development of a new route to obtain cadmium sulfide (CdS) thin films by using ethylene-diamine-tetra-acetic acid (EDTA) ligand on the chemical bath deposition (CBD) method. Different chemical baths are used to study changes in the structures of the CdS films for different EDTA concentrations. X-ray diffraction (XRD) is used to prove the structural characterization of the samples, and to obtain the grain size with the Scherrer´s equation. The pH variations during the growth also affect the structural film quality, and it was verified by using ammonia chloride as an auxiliar-buffer plus Triton-X100.