سال انتشار: ۱۳۸۷

محل انتشار: دومین کنگره بین المللی علوم و فناوری نانو

تعداد صفحات: ۲

نویسنده(ها):

R Halladj – Chemical Engineering Department, Amirkabir University of Technology, P.O.Box: 15875 – ۴۴۱۳, Hafez Ave. Tehran, Iran
S Askari –
B Nasernejad –

چکیده:

Nanosized metal clusters possess chemical and physical properties that are distinct from those of bulk phase or individual molecules and can be used in fields such as optics, optoelectronics and catalysts. In order to gain high performance materials, it is of paramount importance that particle size and structure be controlled [1,2]. One significant approach is to synthesize them in the presence of a porous solid such as alumina, silica, and zeolite.Mesoporous solids, due to their small pore size, high opening pore volume, and large internal surface area, have found great utility.Different techniques for promoting the formation of metal particles loaded mesoporous composites have been developed [3,4] ,but recently there has been a rapid increase in the application of unconventional methods. Different than other traditional chemical methods, sonochemistry is based on acoustic cavitation ,that is ,the formation ,growth and collapse of bubbles in a liquid[5].The adiabatic processing of implosive collapse generates localized hot spots with transient temperature of about 5000K and pressures of 181.8MPa[6].The chemical effects of ultrasound are attributed to the cavitation which produces strong reactants from aqueous solutions, thereby reducing metal salts in situ.Using ultrasound in liquid solid systems for the preparation of nanostructured metals, especially with the presence porous solid, however, is rarely reported in literatures