Nguyen Quoc Hien

• Prof.
• Senior Researcher at Vietnam Atomic Energy Institute

This paper presents a green synthesis method for growing carbon quantum dots (CQDs) from turmeric starch. The CQDs were then used as reducing agents and stabilizers to synthesize dual-shaped gold nanoparticles (AuNPs) with spherical and triangular shapes. In addition to the advantages of CQDs in catalysis, such as their large surface area and the p...

Coffee husks (CH) are waste with abundant reserves in Vietnam. This type of waste is mainly composed of cellulose, hemicellulose, minerals, and some reducing active ingredients such as polyphenols, reducing sugars, and lignin, so it is suitable for use as raw material for producing organic fertilizer for reuse in agriculture. In this study, we pres...

Silver nanoparticles (AgNPs) have been suitably synthesized by reduction of silver ion (Ag⁺) using carbon dots (CDs) as a reducing agent and polyvinylpyrrolidone (PVP) as a stabilizing agent. The purpose of this study was to clarify the efficiency of reducing agent (CDs) for the synthesis of AgNPs. The CDs and AgNPs have been characterized using UV...

Sulfur is one of the inorganic elements used by plants to develop and produce phytoalexin to resist certain diseases. This study reported a method for preparing a material for plant disease resistance. Sulfur nanoparticles (SNPs) stabilized in the chitosan-Cu2+ (CS-Cu2+) complex were synthesized by hydrolysis of Na2S2O3 in an acidic medium. The obt...

Chitosan (CS) samples with average molecular weight (Mw) of 80.4, 61.8, and 45.2 kDa were prepared by the heterogeneous degradation of CS using 1% H2O2 solution under ambient conditions. The degree of deacetylation (DD) of the resultant CS was almost unchanged compared with that of the original CS. The sulfur nanoparticles (SNPs) were prepared by a...

Sulfur nanoparticles (SNPs) in chitosan-copper (CS-Cu ²⁺ ) complex solution were prepared by hydrolysis of sodium thiosulfate (Na 2 S 2 O 3 ) in an acidic medium of CS-Cu ²⁺ complex. The size of SNPs was inversely proportional to the Cu ²⁺ /−NH 2 molar ratio, decreasing from 35 to 22 nm corresponding to the Cu ²⁺ /−NH 2 molar ratio increasing from...

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...

Nano ZnO/chitosan oligosaccharide (ZnO/COS) and nano ZnO/chitosan oligosaccharide-iodine complex (ZnO/COS-I2) prepared in this study are new materials consisting of ZnO nanoparticles (12.3 - 15.0 nm) dispersed in COS and COS-I2 solutions. Both ZnO/COS and ZnO/COS-I2 nanomaterials have the ability to resist Pantoea stewartii (P. stewartii) causes ja...

Chitosan (CS) is only soluble in weak acid medium, thereby limiting its wide utilisation in the field of biomedicine, food, and agriculture. In this report, we present a method for preparing water-soluble CS oligosaccharides (COSs) at high concentration (∼10%, w/v) via the oxidative hydrolysis of CS powder with molecular weight (Mw) ∼90,000 g/mol)...

In this work, we present the results of the ortho-positronium (o-Ps) annihilation lifetimes and nitrogen adsorption measurements for different porous materials and an approach for describing the annihilation of o-Ps in a pore, which results in a surface-volume formula (SVF) for calculating the pore-related o-Ps lifetime. This proposed formula gives...

Searching for thiosemicarbazone derivatives with the potential to inhibit acetylcholinesterase for the treatment of Alzheimer's disease (AD) is an important current goal. The QSARKPLS, QSARANN, and QSARSVR models were constructed using binary fingerprints and physicochemical (PC) descriptors of 129 thiosemicarbazone compounds screened from a databa...

In this study, we proposed a straightforward electrospun polycaprolactone (PCL) loaded with silver nanoparticles (SNPs) membrane fabrication process, in which SNPs were directly synthesized from silver nitrate (AgNO3) in PCL–acetone mixture by gamma irradiation. The insolubility of AgNO3 in PCL solution was solved using an auxiliary dimethyl sulfox...

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...

A synergistic multilayer membrane design is necessary to satisfy a multitude of requirements of an ideal wound dressing. In this study, trilayer dressings with asymmetric wettability, composed of electrospun polycaprolactone (PCL) base membranes coated with oligomer chitosan (COS) in various concentrations of polyvinylpyrrolidone (PVP), are fabrica...

Cu2O nanoparticles (Cu2ONPs) with particle size of ~27.4 nm deposited on diatomite (Cu2ONPs/diatomite), a new low-cost material has been used to investigate growth inhibit, and bloom preventation of cyanobacteria in eutrophic waters. Diatomite collected from natural mines was also used in the experiments. Microcystis aeruginosa strain originated fr...

Environmental pollution, especially water pollution, is of great concern nowadays. Textile wastewater treatment by electron beam irradiation (EB) shows the advantage of not using toxic additives and not creating secondary sludge. In this study, textile wastewater was treated by electron beam irradiation in a low absorbed dose range of 0.5-2 kGy in...

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 nano deposited on TiO2 nano (Ag nano/TiO2) materials with different initial Ag+ content (0.1-0.75%, w/w) were synthesized by Co-60 gamma irradiation and used as photoanode of dye-sensitized solar cells. The characteristics of Ag nano/TiO2 were determined by X-ray diffraction (XRD), transmission electron microscope (TEM) and UV-visible spectr...

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...

Cu 2 O NPs/diatomite is a composite material synthesized by chemical reduction method of Cu ²⁺ ion adsorbed on diatomite. Cu 2 O NPs/diatomite is capable of adsorption of pollutants and microbial treatment, for aquaculture water treatment applications. The study focused on the acute toxicity determination of Cu 2 O NPs/diatomite material on Swiss w...

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...

The textile dyeing industry has created a huge pollution problem because organic dyes are one of the largest groups of pollutants released into environment that are highly toxic and hazardous to the living organism. Recently, more attention has been given to the oxidative removal of various organic pollutants by electrochemically generated hydroxyl...

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...

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...

In this study, electron-beam (EB) irradiation was employed for the degradation of tricyclazole (TC) in an aqueous solution and real pesticide industry wastewater (RPW). Acute toxicity tests revealed that TC exhibits low toxicity against Daphnia magna, with LC50 values of 52.81 mg/L, 32.68 mg/L, 24.35 mg/L and 14.56 mg/L for TC at 24 h, 48 h, 72 h a...

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...

The noble metal-based nanoparticles (NPs) have been considered as potential antimicrobial agents because of their good antibacterial and antifungal activities as well as biocompatible nature. In this study, we have introduced a simple and fast route to synthesize silver, gold, and silver-gold bimetallic NP-decorated dextran. The as-synthesized nobl...

Diatomite is mined in Phu Yen province, Vietnam and the Fe2O3-diatomite materials are synthesized by a simple process for the photo-Fenton reaction of rhodamine B (RhB) degradation. The pure diatomite and Fe2O3-diatomite materials have the large pore structures representing the high adsorption ability and efficient photocatalysis. Characterizations...

Study on a thorough treatment of organic compounds in the polluted environment is always a prime concern of each country. In this study, silver nano doped on TiO2 (Ag nano/TiO2) samples with different initial Ag concentrations in the range of 0.5‐3 % were synthesized by electron beam irradiation method. The synthesized Ag nano/TiO2 material was cha...

Study on electron beam (EB) irradiation of AgNO3/chitosan/Diatomite (DA) suspension mixture was carried out. Influence of AgNO3 precursor’s concentration on the size and the content of silver nanoparticles (AgNPs) deposited in DA was investigated. The TEM images demonstrated the AgNPs in nanocomposite of AgNPs/DA were spherical with an average diam...

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...

Nano-silver-titanium dioxide (Ag-TiO 2 ) composites were prepared from commercial TiO 2 (P25, Degussa) and silver nitrate (AgNO 3 ) by gamma Co-60 irradiation method with various initial concentrations of AgNO 3 . The nano-AgTiO 2 composites are utilized as the photoanode for dye-sensitized solar cells (DSCs). Under full sunlight illumination (1000...

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...

Cu2O‐Cu nanoparticles (Cu2O‐Cu NPs) stabilized by alginate have been developed for using as a plant fungicide. The antifungal effect of Cu2O‐Cu NPs against Neoscytalidium dimidiatum fungus causing brown spot disease in dragon fruit plants was investigated. Transmission electron microscopy (TEM) was used to assess the morphology and size of Cu2O‐CuN...

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...

Functional hybrid materials were successfully synthesized from low-cost waste products, such as oligochitosan (OCS) obtained from chitosan (one of the main components in crab shells) and nanosilica (nSiO2) obtained from rice husk, in a 1:1 ratio (w/w), and their dispersion in the presence of carboxymethyl cellulose at pH 7 was stable for over one m...

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...

This study shows that the pre-exponential frequency in the general-orders of kinetics (GOK) model depends on the ratio between the initial number of trapped electrons (n0) and the total concentration of trapping states (N) as well as the frequency factor. The frequency factor can be calculated by the one trap-one recombination (OTOR) model and does...

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...

In this study, a nanocomposite of silver loaded on TiO2 nanotubes (Ag/TNTs) was synthesized by a gamma irradiation method with a 92.42% yield. The optimized scale for Ag/TNT synthesis was 1.29 g of precursors per 100 mL solvent. The morphology and crystal structure of the Ag/TNTs were determined by transmission electron microscopy and X-ray diffrac...

The kinetic parameters of thermoluminescene (TL) glow peaks of chilli powder irradiated by gamma rays with the different doses of 0, 4 and 8 kGy (i.e. activation energies (E), order of kinetics (b), trapping and recombination probability coefficients (R) and frequency factors (s)) have been determined and evaluated by glow curve deconvolution (GCD)...

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...

Silver - doped titanium dioxide (Ag-TiO 2 ) nanoparticles were prepared from TiO 2 (P25, Degussa) and silver nitrate (AgNO 3 ) by gamma Co-60 irradiation method with various initial concentration of AgNO 3 (0.1 – 0.75%, w/w). The formed silver nanoparticles and optical band gap of Ag-TiO 2 films were investigated by XRD, XRF, TEM and UV-Vis spectro...

The kinetic parameters of thermoluminescence (TL) glow peaks of chilli powder irradiated by gamma rays with the different doses of 0, 4 and 8 kGy have been calculated and estimate by computerized glow curve deconvolution (CGCD) method and the R package tgcd by using the TL glow curve data. The kinetic parameters of TL glow peaks (i.e. activation en...

The preparation of oligochitosan through the heterogeneous degradation of chitosan/H2O2 combined with the homogeneous reaction of chitosan with H2O2 under gamma radiation was studied. Oligochitosan with weight-average molecular weight (Mw) of less than 10 kDa could be efficiently prepared by gamma Co⁶⁰ irradiation of chitosan solution (4%) and hydr...

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...

Commercial TiO2 (P25) doped with metallic silver nanoparticles was prepared by γ-irradiation method. The size of silver nanoparticles (AgNPs) was determined by transmission electron microscopy (TEM) to be of 1-2 nm. The photo-catalytic degradation of azo dye Metyl Red (MR) in the aqueous suspensions of TiO2 and Ag/TiO2 under visible light was carri...

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...

Ag nano deposited on TiO2 (Degussa P25) (Ag nano/TiO2) photo-catalyst has been synthesized by g-irradiation method. The characteristics of Ag nano/TiO2 material has been investigated by BET surface area, X-ray diffraction (XRD), transmission electron microscopy (TEM) and the diffuse reflectance spectra (DRS). The photo-catalytic properties of Ag na...

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...

An electro-deposition approach was established to incorporate the gold nano-flakes onto the glassy carbon electrode in electrochemical cells (nano-Au/GC/ECCs). Using pulsed amperometric detection (PAD) without any gold oxidation for cleaning (non-oxidative PAD), the nano-Au/GC/ECCs were able to maintain their activity for oxidizing of carbohydrates...

Pt nanoparticles on vulcan XC-72R support (Pt/vulcan XC-72R) were prepared by the impregnation?reduction method. The Pt content, the morphological properties and the electrochemical catalysis of the Pt/vulcan XC 72R materials have been investigated by ICP-OES analysis, FESEM, TEM, and cyclic voltammetry. These materials were then used as catalyst f...

Radiation-induced grafting is an effective technique for preparation of novel materials. In this study, partially deacetylated chitin with deacetylation degree (DDA) of about 40% was graft-copolymerized with acrylonitrile (AN) by a γ-ray pre-irradiation method. The maximal grafting degree of AN onto pre-irradiated chitin at 25±1.2 kGy was 114% for...

Sustainable biopolymers are intriguing motifs for transferring the distinct biocompatibility and recognition into inorganic nanoparticles, which have a potential to be used in biomedicine applications. Here we report scalable production of water-soluble chitosan polymers from N-acetylation. One-pot aqueous synthesis of water-dispersible gold nanosp...

The nano-gold layer formed on the platinum rotating disk electrode (nano-Au/Pt-RD) inherited the catalytic property for Cr(VI) reduction from platinum surface and owned the good features of nano-gold such as insensitivity with hydrogen ion, high surface area, augmenting diffusion of Cr(VI) and ability for self-assembling with 4-pyridine-ethanethiol...

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...

Gold nanoparticles (Au-NPs) have been successfully synthesized by utilizing water soluble chitosan as reducing and stabilizing agent. The colloidal Au-NPs were characterized by UV-Vis spectroscopy and transmission electron microscopy (TEM). The results showed that the colloidal Au-NPs had a plasmon absorption band with maximum wavelength in the ran...