Sanoe Chairam. Hands-on fabrication of magnetite nanoparticles on mung bean vermicelli coated with silver nanoparticles by green method for promoting undergraduate student education in chemistry. Doctoral Degree(Science and Technology Education). Mahidol University. : Mahidol University, 2008.
Hands-on fabrication of magnetite nanoparticles on mung bean vermicelli coated with silver nanoparticles by green method for promoting undergraduate student education in chemistry
Abstract:
Three novel chemical experiments have been developed consisting of two
experiments in nanotechnology and one experiment for enhancing student education in
chemical kinetics, namely: (i) magnetic iron oxide nanoclusters, (ii) silver and gold
nanoparticles, and (iii) chemical kinetics of egg shells.
(i) A novel method for fabricating magnetic iron oxide nanoparticles was achieved
by using a transparent vermicelli template consisting of mung bean starch as a new stabilizing
material. The morphology of the as-prepared magnetic iron oxide that was deposited on the
surface of vermicelli was observed as nanoclusters. The magnetization of the magnetic iron
oxide nanoparticles at room temperature was decreased after carbonization at a temperature of
200°C. Furthermore, the thermal decomposition of iron oxide nanoparticles stabilized by
starch vermicelli template yielded magnetic iron oxide/carbon nanocomposites with soft
magnetic behavior, which is useful for biomedical applications.
(ii) Size- and shape-controlled syntheses of silver and gold nanoparticles were
developed using a starch vermicelli template acting as nanoreactors for the growth of
nanoparticles. Pale red colloidal solutions were observed for gold, while purple and yellow
colloidal solutions were observed for silver. The carbonization at different temperatures was
carried out to investigate nanoparticles embedded in vermicelli. The yellow color of silver
was originated from silver nanoparticles while the purple color was originated from a mixture
of silver and silver chloride nanoparticles. This approach offers a great potential for the largescale
synthesis of silver and gold nanoparticles for chemical and biological applications.
(iii) Chemical kinetics is an extremely important concept for introductory chemistry
courses. The instruction in chemical kinetics is often teacher-centered at all levels. This
research seeks to shift students from passive learning to more active, student-centered
learning. The research involved first-year science students at Mahidol University, Thailand.
Drawing on inquiry-based learning, the students were asked to design an experiment
investigating the reaction of acids and bases. The research findings suggested that most
students were able to explain changes in the rate of chemical reactions, and also develop a
good conceptual understanding of chemical kinetics