Abstrakt

Sonophotocatalysis degradation of hydrogels

Rajabali Ebrahimi

One of the commercially important hydrogel based on acrylic acid and acryl amide, (acrylic acid-co-acryl amide) hydrogels have been degraded bymeans of ultrasound irradiation and its combination with heterogeneous (TiO2). 24 kHz of ultrasound irradiationwas provided by a sonicator, while an ultraviolet source of 16Wwas used for UV irradiation. TiO2 sonophotocatalysis led to complete (acrylic acid-co-acryl amide) hydrogels degradation with increasing catalyst loading, while, the presence of TiO2 in the dark generally had little effect on degradation. Therefore, emphasis was totally on the sonolytic and sonophotocatalytic degradation of hydrogels and a synergy effect was calculated for combined degradation procedures (Ultrasound and Ultraviolet) in the presence of TiO2 nanoparticles. TiO2 sonophotocatalysis was always faster than the respective individual processes due to the enhanced formation of reactive radicals as well as the possible ultrasoundinduced increase of the active surface area of the catalyst. Akinetics model based on viscosity data was used for estimation of degradation rate constants at different conditions.