The Synthesis of SiO2 Particles with CTAB as Surfactant and Its Foam Stability for Decontamination Process

The decontamination and decommission technology have been considered as one of the controversial issues in the nuclear society. For the decontamination, chemical decontamination method was widely employed to remove the surfaces contaminated by radionuclides such as radio active Co, and Cs. However, a large amount of liquid waste can be generated when the chemical method was used. Recently, the decontamination foam consisting with surfactant and nanoparticle has been regarded as an another method to remove the contaminated surface. Because the foam could reduce the volume of secondary waste. However, foam is actually a thermodynamically unstable system. Therefore, foam stability is key factor for decontamination. The foam stability can be tuned by mixing surfactants and nanoparticles. Our group reported that the foam stability of surfactant was improved with silica nanoparticle as a foam stabilizer. Thus, it is desirable when the surfactant or nanoparticle can be reduced for foam generation. In this work, we synthesized silica particle with low surfactant for decontamination foam by using co-condensation method based on sodium hydroxide catalyzed reactions of tetraethoxysilane (TEOS) with the cetyltrimethyammonium bromide (CTAB) as a surfactant. Its foam stability of as-synthesized silica was investigated as a function of different synthesis conditions.