Contrasting effects of γ-irradiation on the role of sorbed water assisting the protonic conduction in US-HY zeolite

Dielectric properties and specific conductivity of armenian natural clinoptilolite irradiated by electrons

“…Among these, clinoptilolite, with high ratio of Si/Al, is of special interest and has large applications in industry and agriculture. The investigation of zeolite dielectric characteristics during the hydration and dehydration processes gives important information on its sorption capacity and catalytic activity [2][3][4][5][6]. The measurement of zeolite dielectric permittivity and a.c. conductivity, which are ionic or mixed electronic/ionic, is frequently used for studying the water sorption properties, whereas the absorbed water molecules in zeolites close to room temperature play a dominant role in electrical behaviors [7].…”

“…The measurement of zeolite dielectric permittivity and a.c. conductivity, which are ionic or mixed electronic/ionic, is frequently used for studying the water sorption properties, whereas the absorbed water molecules in zeolites close to room temperature play a dominant role in electrical behaviors [7]. The radiation effects in zeolites are less investigated, although radiation modifications of these materials can change their sorption and other properties [5][6][7][8][9]. The irradiation induces structural radiation defects with controllable concentration and type without changing the stoichiometry of irradiated material.…”

“…The irradiation induces structural radiation defects with controllable concentration and type without changing the stoichiometry of irradiated material. Irradiation is a good tool for modifying and, in some cases, enhancing the physical and chemical properties of different materials, including zeolites ones [5,6,8,[9][10][11][12][13][14]. Thus, through irradiation, it is possible to control sorption and other properties of zeolite.…”

“…[6] reported that irradiation of US-HY zeolite by ionizing γ-rays induces contrasting effects. Authors of ref.…”

“…For example, the γ-irradiation, with doses up to 100 MRad, of dealuminated ultra-stable US-HY zeolite samples increases the specific conductivity (σ) almost by an order of magnitude [6]. The growth of σ at small doses of irradiation can be attributed to the increased mobility, or concentration, of protons, whereas at higher doses the observed reduction of σ can be due to radiation-induced dehydration and narrowing of channels of a sample [6].…”