Nguyen Ngoc Duy

Synthesis of Gold Nanoparticles Stabilized in Dextran Solution by Gamma Co-60 Ray Irradiation and Preparation of Gold Nanoparticles/Dextran Powder

Gold nanoparticles (AuNPs) in spherical shape with diameter of 6–35 nm stabilized by dextran were synthesized by γ-irradiation method. The AuNPs were characterized by UV-Vis spectroscopy and transmission electron microscopy. The influence of pH, Au3

EFFECT OF NANOSILICA FROM RICE HUSK ON THE GROWTH ENHANCEMENT OF CHILI PLANT (Capsicum frutescens L.)

Nanomaterials hold great promise of improved plant disease resistance, controlled release of agro-chemicals, enhanced plant growth, etc. In t his study, the effect of nanosilica (10 – 30 nm) prepared from rice husk on the growth promotion of chili plant in green house was carried out. The experiment of nanosilica treatment by foli ar spraying was arranged in a factorial design with 3 replications at various nanosilica concentra tions of 0, 40, 60 and 100 ppm. Plant growth characteristics and chlorophyll content were assess ed. Results showed that the fresh weight, dry weight, and chlorophyll content increased with the tr atment of nanosilica. The optimal concentration of nanosilica was found to be of 60 p pm. Thus, treatment of nanosilica was beneficial in enhancing the growth of the chili pla nts.

DEGRADATION OF CHITOSAN BY γ-IRRADIATION OF CHITOSAN SWOLLEN IN HYDROGEN PEROXIDE SOLUTION

ABSTRACT Degradation of chitosan in swollen state with hydrogen peroxide solution (1–5% w/v) by γ-irradiation was investigated. Molecular weight (Mw) of irradiated chitosan samples was determined by gel permeation chromatography (GPC). Fourier transform infrared (FT–IR) spectra and X–ray diffraction (XRD) patterns were utilized to study the structure of degraded chitosan. Results showed that low Mw chitosan of ~30–45 kDa was efficiently prepared by γ–irradiation of chitosan (Mw 0 ~91.7 kDa) swollen in hydrogen peroxide solutions at low dose less than 20 kGy. The main structure as well as the degree of deacetylation of degraded chitosan was almost unchanged. Furthermore, the radiation degradation yield (G s ) was remarkably enhanced with the presence of H 2 O 2 as a sensitizer. Degradation of chitosan in swollen state with hydrogen peroxide solution by γ-irradiation is efficient for preparation of low Mw chitosan at low dose.