Dang Van Phu

• PhD
• Researcher, deputy head of R&D at Research and Development Center for Radiation Technology, Vietnam Atomic Energy Institute

Silver and copper nanoparticles are well-known as good antimicrobial agents. In this study, we reported the preparation and characterization of bimetallic silver-copper nanoparticles (Ag-CuNPs) prepared by the electron beam (EB) irradiation method. Chitosan (CTS) was used as a stabilizer agent. The obtained Ag-CuNPs were characterized by X-ray diff...

In this study, Maillard reaction with glucosamine (GA) induced by gamma irradiation was applied for chitosan (CT) and oligochitosan (OC) to improve the solution stability and antibacterial activity under alkaline condition. The mixture solutions of CT and/or OC with GA were irradiated at the dose of 25 kGy to form the Maillard reaction products (MR...

In this study, the gamma ray-induced Maillard reaction method was carried out for chitosan (CTS) and glucosamine (GA) to improve the water solubility and antibacterial activity. The mixture solution of CTS and GA was exposed to gamma rays at a dose of 25 kGy and freeze-dried to obtain a Maillard reaction product (MRP) powder. The physicochemical an...

Anthracnose caused by Colletotrichum truncatum (C. truncatum) fungus, a seriously damaged in many soybean growing areas, has almost no effective control strategy. Recently, biostimulants for disease prevention of plants have been considered a feasible solution. In this study, the chitinase-induced effect on soybean plants of various oligochitosan-Z...

The Maillard reaction products of chitosan and glucosamine (CTS-GA MRPs) were formed by gamma Co-60-irradiation method and determined their minimum bactericidal concentrations (MBC). The mixed solutions of chitosan - glucosamine were irradiated with a dose range of 0-100 kGy to induce the Maillard reaction products (MRPs). The formations of MRPs we...

Silver nanoparticles (AgNPs) doped in the zeolite framework (AgNPs/Z) were successfully synthesized by γ-irradiation in ethanol solution of silver ion-zeolite (Ag+/Z) prepared by ion exchange reaction between silver nitrate (AgNO3) and zeolite 4A. The effects of the Ag+ concentration and irradiation dose on the formation of AgNPs/Z were also invest...

The mixture solutions of glucosamine and chitosan with different molecular weights(123.5; 40.7 and 6.1 kDa) were irradiated by Co-60 gamma ray at dose of 50 kGy to prepare chitosanglucosamine Maillard reaction products (MRPs). The formation of MRPs was determined by measuring UV absorbance (at 284) nm and browning (at 420 nm). The reaction efficien...

Maillard reactions between chitosan and glucosamine were induced by Co-60 gamma irradiation method and the antibacterial and antioxidant activities of resulting products were investigated. Briefly, a mixture of chitosan (1%) - glucosamine (0.5%) was irradiated with a dose range of 0-100 kGy. The Maillard reaction products of chitosan and glucosamin...

Among nanoparticle materials, selenium nanoparticles (SeNPs) have attracted wide spread attention due to their excellent bioavailability, high bioactivity and low toxicity compared to other ionic selenium compounds. SeNPs with size ~ 41.75 nm were synthesized by γ-irradiation method using oligochitosan (OC) as stabilizer. The prepared SeNPs/OC were...

Radiation technology has been providing a useful tool to modify polymers involving the radiation crosslinking of hydrogels. In the present work, two kinds of hydrogels composed gelatin and carboxymethyl chitosan (gelatin/CM-chitosan), and carboxymethyl chitin (gelatin/CM-chitin) were prepared by the radiation crosslinking. The resulting hydrogels w...

Cu nanoparticles are a potential material for creating novel alternative antimicrobial products due to their unique antibacterial/antifungal properties, stability, dispersion, low cost and abundance as well as being economical and ecofriendly. In this work, carboxymethyl cellulose coated core/shell SiO2@Cu nanoparticles (NPs) were synthesized by a...

In this study, nano Cu 2 O-Cu/alginate was synthesised by the chemical reduction of tetra-amminecopper (II) ion complexes soluble using hydrazine as a reducing agent and alginate as a stabiliser. The influence of various copper ion concentrations on particle size and morphology of produced nano Cu 2 O-Cu/alginate was investigated. The transmission...

Owing to their excellent bioavailability, high bioactivity, and low toxicity, selenium nanoparticles (SeNPs) are emerging nanomaterials. In this study, SeNPs with a size of ∼41.8 nm were synthesised by γ-irradiation using oligochitosan (OCS) as the stabiliser. As-synthesized SeNPs/OCS were characterised by UV-Vis spectroscopy, transmission electron...

Owing to their excellent bioavailability, high bioactivity, and low toxicity, selenium nanoparticles (SeNPs) are emerging nanomaterials. In this study, SeNPs with a size of ∼41.8nm were synthesised by c-irradiation using oligochitosan (OCS) as the stabiliser.As-synthesizedSeNPs/OCSwerecharacterisedbyUV-Visspectroscopy,transmissionelectronmicroscopy...

Background: Rice blast disease due to Pyricularia oryzae fungus is one of the most destructive ones for rice, causing serious losses in yield and quality in Vietnam and other countries. Studying to develop new fungicides to control the fungal disease effectively is essential.Methods: The sodium alginate-stabilized Cu-Cu2O nanocolloidal solution wit...

Textile wastewater is known to have a large number of hazardous pollutants, intense color and high chemical oxygen demand (COD) concentration. The electron beam method is considered useful in treatment textile wastewater through chemical oxidation process. In this study, three real textile wastewaters (Sample 1: Reactive Black 5, Reactive Red 10, a...

This study presents the structural characteristics and the antifungal efficiency of the oligochitosan-Zn ²⁺ complexes. Oligochitosan with the average molecular weight of ~5 kDa was effectively prepared by gamma-ray irradiation degradation of chitosan in a solution containing H 2 O 2 . The oligochitosan-Zn ²⁺ complexes with the different molar ratio...

Anthracnose is the severely devastating disease in soybean cultivation. Employing chemical fungicides have been limited in modern agriculture. Currently, the oligochitosan (OC) and OC-Zn 2+ complex have been evaluated as efficient fungicides. However, finding a proper method to produce them is still being actively encouraged. This work presents a p...

Chitooligosaccharides (COS) were prepared by hydrogen peroxide (1%) degradation of chitosan solution (3%) in dilute lactic acid at ambient temperature. The molecular weights of degraded chitosan were measured by gel permeation chromatography, and the chemical structure of resultant COS were characterized by Fourier transform infrared spectra. The d...

Platinum nanoparticles were synthesized using the gamma-ray irradiation as a reducing factor and chitosan as a stabilizer. The prepared platinum nanoparticles were characterized using ultraviolet-visible spectroscopy (UV-Vis), transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FT-IR). The saturated conversion dose...

Silica nanoparticles (SiO2 NPs) were synthesized from rice husk ash (RHA) by chemical treatment and calcination. The size of SiO2 NPs evaluated by transmission electron microscope (TEM) was of 20 - 50 nm and the size distribution of SiO2 NPs measured by dynamic laser scattering (DLS) was of Gaussian mode. The X-ray diffraction (XRD) pattern with on...

The brown spot disease caused by Neoscytalidium dimidiatum fungus on dragon fruit plants (Hylocereus undatus) is an extremely serious disease. Oligochitosan (OC) and nanosilica (nSiO2) have been considered as effective plant elicitors. In this study, OC with Mw of 3000, 5000, and 7000 g/mol was prepared by γ-irradiation and nSiO2 with size ~ 45 nm...

Oligochitosan (OC) is effective biostimulant on growth promotion and elicitation against disease infection for plants. However, the range of OC molecular weight that exhibits the most effective activity is not fully understood and requires further investigation. In this study, OCs with different weight average molecular weight (Mw) were prepared by...

Absract Selenium nanoparticles (SeNPs) with diameter of ∼74 nm were synthesized by gamma Co-60 ray irradiation of H2SeO3/dextran solution. The SeNPs were characterized by UV–Vis spectroscopy spectrum and transmission electron microscope (TEM) images. The effect of pH of H2SeO3/dextran solutions before gamma irradiation on the size of SeNPs was inve...

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, Au ³⁺ concentration, and dextran concentration on the size of AuNPs was investigated. Results indicated...

New biopolymer oligochitosan (OCS) and OCS/nanosilica (OCS/nSiO2) hybrid materials with remarkable synergistic effects are likely to be considered natural vaccines for the growth and disease resistance of plants. This study indicated that OCS (50 mg l−1), nSiO2 (60 mg l−1) and OCS/nSiO2 (50:50 mg l−1:mg l−1) not only created effective anti-fungal a...

Oligochitosan (COS) was prepared by gamma Co-60 irradiation of chitosan/H2O2 solutions and mixed with cornstarch to form the powder with content of 100 000 mg COS/kg. The striped catfish (P. hypophthalmus) was fed with diets containing 100 mg COS/kg feed for 9 months at pond culture. The effects of COS supplementation on growth performance, feed co...

Cuprous oxide (Cu 2 O) nanoparticles in zeolite A were synthesized by two steps: (i) ion-exchange of copper ions into the zeolite and (ii) reduction of copper ions in cages of the zeolite by hydrazine hydrate in base medium. The Cu 2 O nanoparticles/zeolite product was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM)...

Oligochitosan (OC) with molecular weight Mw of 5000 g/mol was prepared by gamma Co-60 ray irradiation of chitosan solution. Nanosilica (nSiO2) with the size of 10 - 30 nm was synthesized by calcination of acid treated rice husk. The mixture of 1% OC - 1% nSiO2 was prepared by dispersion of nSiO2 in OC solution. The morphology of nSiO2 in the mixtur...

In recent years, the potential antimicrobial activity of oligosaccharides (such as chitosan, alginate and carrageenan) and their derivatives has received considerable attention. Numerous studies were conducted showing that oligosaccharides could be effective against different groups of microorganisms, such as bacteria, yeast and fungi. Some of the...

Nanomaterials hold great promise of improved plant disease resistance, controlled release of agro-chemicals, enhanced plant growth, etc. In this 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 foliar spraying was arr...

Oligochitosan (COS) and oligo-β-glucan (βOG) were prepared by gamma Co-60 irradiation of chitosan/H2 O2 and β-glucan/H2 O2 solutions. The striped catfish (P. hypophthalmus) was fed by diets containing 0 - 200 mg COS, βOG and mixture of COS/βOG per kg feed for 45 days, and then challenged with Edwardsiella ictaluri bacterium. The effects of suppleme...

Oxidation can generate free radicals which damage important molecules including lipids, proteins, and nucleic acid, and causes premature aging. The oxidation of skin cells manifests as wrinkles, freckles and many other serious symptoms. To develop natural products with high antioxidant ability for skin care, we developed mixtures of Spirulina plate...

Colloidal silver nanoparticles (AgNPs) with particle size less than 10 nm and concentration of 2 mM/L (~200 mg/L) were synthesized by gamma Co-60 ray irradiation of Ag+/chitosan solutions with different chitosan concentration of 0.5%, 1% and 2% (w/v). Incorporation of AgNPs onto cotton fabric was carried out by padding method with 100% wet pick-up....

Degradation of chitosan in swollen state with hydrogen peroxide solution (5% w/v) by γ-irradiation was investigated. Molecular weight (Mw) of irradiated chitosan was determined by gel permeation chromatography (GPC). Fourier transform infrared (FT-IR) and ultraviolet-visible (UV-vis) spectrawere analyzed to study the structure changes of degraded c...

Colloidal solutions of 1 mM gold nanoparticles (AuNPs) were synthesized by γ-ray Co-60 and electron beam irradiation using 1% water soluble chitosan (WSC) with different molecular weight (Mw) as stabilizer. The AuNPs size measured from TEM images was of 7.1 and 15.1 nm for electron beam and γ-ray Co-60, respectively. The AuNPs sizes of 9.8, 15.1 an...

Silk fibers and silk proteins have been demonstrated to be useful to apply in the textile industry, biomedical, cosmetics, pharmaceuticals. In this study, the effects of electron beam (EB) irradiation combined with hydrothermal processing to the solubility of silk fibroin and generation of soluble silk protein were investigated. The solubility of u...

Porous ceramic candle filters (PCCF) were prepared by sintering silica from rice husk with silver nanoparticles (AgNPs)/zeolite A at about 1050 °C to create bactericidal PCCF/AgNPs for water disinfection. The silver content in PCCF/AgNPs was of 300–350 mg kg−1 determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and the a...

In the present research work we evaluate the in vivo distribution of gold nanoparticles (AuNPs) at different time durations after intravenous administration in mice. AuNPs with size of about 20 nm and concentration of 1 mM were synthesized by gamma irradiation method using 0.5% alginate as a stabilizer. AuNPs were characterized by UV-Vis spectrum a...

Colloidal solutions of silver nanoparticles (AgNPs) were synthesized by gamma Co-60 irradiation using different stabilizers, namely polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), alginate, and sericin. The particle size measured from TEM images was 4.3, 6.1, 7.6, and 10.2 nm for AgNPs/PVP, AgNPs/PVA, AgNPs/alginate, and AgNPs/sericin, respec...

Silver nanoparticles (AgNPs) with diameter about 12nm were immobilized on the surface of cotton fabrics by γ-irradiation of fabrics in the AgNO3 chitosan solution. Effects of absorbed dose, concentration of AgNO3 solution on immobilization of the AgNPs on fabrics were investigated. The optimal dose was selected to be 13.8kGy and the suitable concen...

Degradation of chitosan in swollen state with hydrogen peroxide solution (5% w/v) by γ-irradiation was investigated. Molecular weight (Mw) of irradiated chitosan was determined by gel permeation chromatography (GPC). Fourier transform infrared (FT-IR) and ultraviolet-visible (UVvis) spectrawere analyzed to study the structure changes of degraded ch...

Silver nanoparticles (AgNPs) deposited on silica were synthesized by gamma Co-60 irradiation of Ag+ dispersion in silica/ethanol/water mixture (9/80/20:w/v/v). The reduction of Ag+ is occurred by hydrated electron (e-aq) and hydrogen atom (H•) generated during radiolysis of ethanol/water. The conversion doses (Ag+→ Ag0) were determined by UV-Vis sp...

Gold nanoparticles (AuNPs) with size in the range of 10-50 nm were synthesized by gamma Co-60 irradiation using water soluble chitosan (WSC) as stabilizer and size enlargement by seed approach. The maximum absorption wavelength (lambda(max)) was measured by UV-vis spectroscopy and particle size was determined from TEM images. Results showed that va...

Polyethylene nonwoven (PE) fabric was grafted with acrylic acid (PE-g-PAAc) by the γ-ray pre-irradiation process. The effect of dose and acrylic acid concentration on the grafting degree was investigated. The dose of about 20-30 kGy, acrylic acid concentration of 20-30%, and the reaction time of about 2 h at ˜90 °C were selected as suitable paramet...

Gold nanoparticles (AuNPs) with diameter from 4 to 10 nm, capping by hyaluronan (HA) were synthesized using a γ-irradiation method. The maximum absorption wavelengths at 517–525 nm of colloidal AuNPs/HA solutions were measured by UV–vis spectroscopy. The size and size distribution of AuNPs were determined from TEM images. The influence of various f...

Chitosan from squid pens with deacetylation degree (DD) of 70% and average molecular weight (M(wo)) 90.5 x 10(3) in dilute lactic acid solution containing H(2)O(2) (1%) was effectively degraded by irradiation with gamma (60)Co radiation (1.33 kGy/h) at doses in the range 4-16 kGy. Based on the results of M(w) measured by gel permeation chromatograp...

Synergistic degradation of chitosan by γ-irradiation of chitosan solution (3%) in the presence of hydrogen peroxide (0.25%, 0.5% and 1%) was investigated. The efficiency of the degradation process was demonstrated by gel permeation chromatography (GPC) analysis of the average molecular weight of degraded chitosan (oligochitosan). Structures of resu...

Gold nanoparticles with pre-selected size in the range 5–40 nm were synthesized by γ-irradiation of Au3+ solution containing natural polysaccharide alginate as a stabilizer. The gold nanoparticles with controllable size were prepared by two approaches: (i) varying the concentration of Au3+ from 0.25 to 1 mM and alginate from 0.25% to 1% (w/v) and (...

Radiation-induced synthesis of colloidal silver nanoparticles (Ag-NPs) using chitosan (CTS) as a stabiliser and free radical scavenger is feasible and satisfiable to green method. The conversion dose (Ag+ into Ag0) was determined by UV-Vis spectroscopy and Ag-NPs size was characterised by transmission electron microscopy. The average diameter of Ag...

Colloidal silver nanoparticles were prepared by γ-irradiating Ag in aqueous solution in the presence of 2% polyvinyl pyrrolidone (PVP) as stabilising agent and ethyl alcohol as free radical (OH) scavenger. The saturated conversion dose of Ag into Ag was determined by UV–Vis spectroscopy and the silver nanoparticles size was characterised by transmi...

Radiation processing technology is proved to be a useful tool for modification of polymer material including grafting of monomer onto polymer. In this study, partially deacetylated chitin (PD-chitin) was prepared by soaking chitin in NaOH solution with various concentrations from 10% to 50% (w/w) at room temperature for four days. The degree of dea...