Synthesis of Nanoparticles and One-Dimensional Nanomaterials - Nanotechnologies for Water Environment Applications - page 24

solution purged with argon gas was irradiated by ultrasound at room temperature.
The final product was Pd nanoparticles with diameters around 5 to 6 nm in the
mesopore of the mesoporous silica. In addition, mesoporous iron-titania catalyst
was also synthesized using this method. The as prepared titania was immersed
into the iron pentacarbonyl in decalin, and the mixture then was irradiated by
ultrasound under an atmospheric pressure of air at 0 °C (Perkas et al., 2001).

3) Deposition of nanoparticles on ceramic and polymeric surfaces (Ramesh et al.

1997; Pol et al., 2002; Gedanken, 2007). The Sonochemical method can deposit
various nanoparticles (i.e., metals, metal oxides, semiconductors) on the surface
of ceramic and polymeric materials. For example, silver nanoparticles of 5 nm
size were deposited on the surface of submicron size of silica (Pol et al., 2002).
The ultrasonic irradiation process was conducted with the slurry of silica
submicronsphere, silver nitrate, and ammonia under a flow of an argon/hydrogen
mixture. The product was dried and stored under the argon condition. In addition,
polyaniline/nanocrystalline TiO 2 composite particles was synthesized
sonochemically (Xia and Wang, 2002). Nanocrystalline TiO 2 particles, aniline,
ammonium peroxydisulfate (NH 4 ) 2 S 2 O 8 , concentrated HCl aqueous solution,
sodium lauryl sulfate (SLS) and deionized water were mixed in the reaction
vessel. The mixture then was deoxygenated by nitrogen. After this step,
ultrasonic irradiation was carried out to obtain the desired nanoparticles. Beside
these examples, there are various nanoparticles doped in various host materials.
Some examples are listed in Table 2.3.

Table 2.3 Examples of the nanoparticles doped sonochemically in various host.
NP Type Matrix Reference NP Type Matrix Reference

Sivakumar and
Gedanken
(2005)

Amorphous
Fe

Wizel et al.
(2000)

polystyrene Au Polyaniline

polyvinyl
alcohol

Kumar et al.
(2000)

Xia and Wang
(2002)

Fe 3 O 4 TiO 2 Polyaniline

poly( N -
vinylpyrrolid
one)

polyvinyl
alcohol

Kumar et al.
(2001)

Carotenuto
(2001)

CuO Ag

Kumar et al.
(2002)

Patra et al.
(1999)

Ni polystyrene Eu 2 O 3 Alumina

2.2.7 Microwave Assisted Method

Recently, the microwave assisted method has been extensively employed for the
synthesis of nanomaterials that include both inorganic and organic materials (Hoz et al.,
2005; Apte et al., 2006). Compared with other conventional methods, the microwave