Sonochemical Synthesis of Spherical Silica Nanoparticles and Polymeric Nanocomposites

Abstract

In this work spherical SiO 2 nanoparticles were synthesized by sonochemical method using a new Schiff-base as a capping agent. The silica nanoparticles were obtained by hydrolysis of tetraethyl orthosilicate in aqueous alcohol solution. The effect of different parameters such as molar concentration of Schiffbase ligands and ultrasonic irradiation on the morphology and size of the products was examined. The results demonstrated that applying the appropriate amount of Schiff-base could be effective in control of particle size. The influence of SiO 2 nanostructures on the flame retardancy of the poly styrene, poly vinyl alcohol, cellulose acetate and ethyl cellulose was studied. In-situ and ex situ nanocomposites were investigated and results confirm that flame retardancy of in situ nanocomposites were better than ex situ samples. HOÁÁÁSi-O-SiÁÁÁOH barrier prevents reaching of flame, heat and oxygen to the polymeric nanocomposites.

Sonochemical catalysis as a unique strategy for the fabrication of nano-/micro-structured inorganics

“…[147] The average diameters of silica particles were distributed in the range from 40 to 400 nm, and could be controlled by the reactants' molar ratio which determined the nucleation and growth rates of particles. Salavati-Niasari et al also synthesized spherical SiO 2 nanoparticles by the sonochemical method, [148] and dissimilarly, the schiff-bases (i.e., bis(acetylacetonato)propylene-1,3-diimine and bis(acetylacetonato) buthylene-1,4-diimine) acted as a capping agent for the hydrolysis of tetraethyl orthosilicate in aqueous alcohol solution. The molar concentration of schiff-base ligand could be effective in control of particle size, but the conclusions for bis(acetylacetonato)propylene-1,3-diimine and bis(acetylacetonato) buthylene-1,4-diimine were inconsonant, which was not further explained.…”

Highly sensitive and selective detection of glutathione using ultrasonic aided synthesis of graphene quantum dots embedded over amine-functionalized silica nanoparticles

“…Moreover, the presence of ammonia as part of a catalyst has been reported as a precursor in the synthesis of spherical and monodisperse silica nanoparticles from an aqueous alcohol solution of silicon alkoxides. Additionally, various methods have been employed in the preparation of silica nanoparticles, including sonochemical, microemulsion, and Stober methods [13] , [14] , [15] with different sizes and morphology [16] , [17] , [18] . In recent years, the sonochemical method has become an important way to synthesize novel nano-sized materials under ambient conditions.…”

The effect of using solvent medium in the ultrasonication of silica precipitates

“…Many of these applications are related to the physicochemical properties of nanosilica which are not found when present in bulk form [3]. The reactivity of nanoparticle materials can differ depending on their morphology, particle size and distribution [1], [4].…”

“…Silica can be synthesized from several kinds of natural materials such as marine sponge and diatoms, rice husk [5], quartz sand [6], [7], fly ash [8], ferronickel slag, etc. The synthesis method used can be through a chemical reaction with a leaching process [6], [9], microwave [10], [11], hydrothermal [12], [13], sol-gel [14], and sonochemistry [4], [5], [15], [16]. From these synthesis processes, silica can be produced with various sizes and certain morphological shapes, for example cubic, spherical, and mesoporous [2], [4].…”

“…The synthesis method used can be through a chemical reaction with a leaching process [6], [9], microwave [10], [11], hydrothermal [12], [13], sol-gel [14], and sonochemistry [4], [5], [15], [16]. From these synthesis processes, silica can be produced with various sizes and certain morphological shapes, for example cubic, spherical, and mesoporous [2], [4].…”