2 research outputs found
Hydrogen Peroxide Stability in Silica Hydrogels
Hydrogen
peroxide (H<sub>2</sub>O<sub>2</sub>) entrapment in silica hydrogels
has potential to be used in various industrially important applications
to increase H<sub>2</sub>O<sub>2</sub> stability. In this study, optimum
conditions for hydrogel formation and H<sub>2</sub>O<sub>2</sub> stability
were determined by varying the sodium content and initial H<sub>2</sub>O<sub>2</sub> concentration. Higher retention and better stability
of H<sub>2</sub>O<sub>2</sub> were achieved with hydrogels at room
temperature at low sodium concentration. Retention values of 89% were
obtained with initial H<sub>2</sub>O<sub>2</sub> concentrations up
to 10 wt %. H<sub>2</sub>O<sub>2</sub> decomposition in hydrogels
followed a first-order reaction. Hydrogels were characterized by measuring
their surface area, pore size, and pore size distribution by Brunauer–Emmett–Teller
analysis and scanning electron microscopy. Mesoporous (3–24
nm) hydrogels with high surface area (1000–1400 m<sup>2</sup>/g) were obtained. In addition, the melting point of the entrapped
H<sub>2</sub>O<sub>2</sub>-water mixture in the hydrogels was studied
by low temperature differential scanning calorimetry