Effects of ultrasound on the synthesis of silicalite-1 nanocrystals

• Published in: Ultrasonics sonochemistry 2012-09, Vol.19 (5), p.1108-1113
• Main Authors: Gürbüz, Hale, Tokay, Begüm, Erdem-Şenatalar, Ayşe
• Format: Article
• Language: English
• Subjects: Chemistry; Colloidal state and disperse state; Crystallization; Exact sciences and technology; General and physical chemistry; Ion-exchange; Nanoparticles; Nanoparticles - chemistry; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Silicalite-1; Silicates - chemical synthesis; Silicates - chemistry; Surface physical chemistry; Synthesis; Time Factors; Ultrasonic chemistry; Ultrasonics; Ultrasound; Zeolites: preparations and properties
• ISSN: 1350-4177; 1873-2828
• DOI: 10.1016/j.ultsonch.2012.01.008

► Ultrasound increases nucleation, particle growth and crystallization rates. ► Sonication enables synthesis of smaller silicalite-1 particles at shorter times. ► Particle size distributions remain similar for similar average particle sizes. ► Rate of increase in product yield is also speeded up by sonication. ► Final product yield is not affected as a result of the application of ultrasound. Application of power ultrasound, offers potential in the degree of control over the preparation and properties of nanocrystalline zeolites, which have become increasingly important due to their diverse emerging applications. Synthesis of silicalite-1 nanocrystals from a clear solution was carried out at 348K in the absence and presence of ultrasound of 300 and 600W, in an attempt to investigate the effects of sonication, in this respect. Variation of the particle size and particle size distribution was followed with respect to time using a laser light scattering device with a detector set to collect back-scattered light at an angle of 173°. Product yield was determined and the crystallinity was analyzed by X-ray diffraction for selected samples collected during the syntheses. Nucleation, particle growth and crystallization rates all increased as a result of the application of ultrasound and highly crystalline silicalite-1 of smaller average particle diameter could be obtained at shorter synthesis times. The particle size distributions of the product populations, however, remained similar for similar average particle sizes. The rate of increase in yield was also speeded up in the presence of ultrasound, while the final product yield was not affected. Increasing the power of ultrasound, from 300 to 600W, increased the particle growth rate and the crystalline domain size, and decreased both the final particle diameter and the time required for the particle growth to reach completion, while its effect on nucleation was unclear.