Nay Ming Huang | Xiamen University Malaysia (original) (raw)

Papers by Nay Ming Huang

This study reports on a polymer composites which use low density polyethylene (LDPE) as polymer m... more This study reports on a polymer composites which use low density polyethylene (LDPE) as polymer matrix, titanium dioxide (TiO 2) and graphene oxide (GO) as fillers. The results between mechanical and thermal properties of binary system and ternary system composites are being compared with the effect of graphene oxide. The preparation of TiO 2 /GO fillers is done by physical mixing with ratio 1:1 of titanium dioxide and graphene oxide which was prepared using simplified Hummer's method. 5 wt% and 10 wt% of the fillers are then melt mixed with LDPE respectively at 160°C, rotor speed of 60rpm for 10 minutes using Brabender machine. The results confirmed that the incorporation of GO in ternary system showed improvement in tensile and flexural properties compared to binary system composites. For thermal behaviour, ternary system composites showed higher cyrstallinity in differential scanning calorimety (DSC) study than the binary composites, however ternary system composites has slightly decrease for the thermal stability in thermogravimetric analysis (TGA). The investigation on the Lim et al. 462 tensile fractured surface using scanning electron microscope (SEM) showed better interfacial adhesion in ternary system compared to the binary system. Thus, results revealed that polymer composite based on ternary system displayed a remarkable enhancement in mechanical properties which make it a good candidate in food packaging application.

A simple single-stage approach, based on the hydrothermal technique, has been introduced to synth... more A simple single-stage approach, based on the hydrothermal technique, has been introduced to synthesize reduced graphene oxide/titanium dioxide nanocomposites. The titanium dioxide nanoparticles are formed at the same time as the graphene oxide is reduced to graphene. The triethanolamine used in the process has two roles. It acts as a reducing agent for the graphene oxide as well as a capping agent, allowing the formation of titanium dioxide nanoparticles with a narrow size distribution (similar to 20 nm). Transmission electron micrographs show that the nanoparticles are uniformly distributed on the reduced graphene oxide nanosheet. Thermogravimetric analysis shows the nanocomposites have an enhanced thermal stability over the original components. The potential applications for this technology were demonstrated by the use of a reduced graphene oxide/titanium dioxide nanocomposite-modified glassy carbon electrode, which enhanced the electrochemical performance compared to a conventional glassy carbon electrode when interacting with mercury(II) ions in potassium chloride electrolyte.

SnO2 nanoparticles/graphene (SnO2/GP) nanocomposite was synthesized by a facile microwave method.... more SnO2 nanoparticles/graphene (SnO2/GP) nanocomposite was synthesized by a facile microwave method. The X-ray diffraction (XRD) pattern of the nanocomposite corresponded to the diffraction peak typical of graphene and the rutile phase of SnO2 with tetragonal structure. The field emission scanning electron microscope (FESEM) images revealed that the graphene sheets were dotted with SnO2 nanoparticles with an average size of 10 nm. The X-ray photoelectron spectroscopy (XPS) analysis indicated that the development of SnO2/GP resulted from the removal of the oxygenous groups on graphene oxide (GO) by Sn2+ ions. The nanocomposite modified glassy carbon electrode (GCE) showed excellent enhancement of electrochemical performance when interacting with mercury(II) ions in potassium chloride supporting electrolyte. The current was increased by more than tenfold, suggesting its potential to be used as a mercury(II) sensor.

Porous-structured nickel oxide (PsNiO) was obtained through the oxidization of a nickel thin film... more Porous-structured nickel oxide (PsNiO) was obtained through the oxidization of a nickel thin film. The nickel thin film was deposited using the pulsed laser deposition (PLD) method on a nickel foil as a substrate. The results show uniform PsNiO after the oxidization of the nickel thin film at 750 degrees C for 1 h. X-ray diffraction (XRD) indicates formation of the NiO crystalline structure. Field emission scanning electron microscopy (FESEM) reveals different morphology on the surface of the nickel foil (sample A) and on the nickel thin film (sample B). Comparison of the FESEM results after oxidization shows that the PsNiO on the nickel thin film was more regular and controllable than the NiO layer on the nickel foil. The FESEM images also show that the thickness of the nickel thin film affected the PsNiO size obtained after oxidization. This resulted from the growth of the porous structure at grain boundaries and from the grain sizes. The electrochemical properties of the PsNiO as an electrode are investigated by cyclic voltammetry (CV). These results show the effect of PsNiO size on the current of anodic peak.

A simple, cost-effective, efficient, and green approach to synthesize iron oxideigraphene (Fe3O4/... more A simple, cost-effective, efficient, and green approach to synthesize iron oxideigraphene (Fe3O4/rGO) nanocomposite using in situ deposition of Fe3O4 nanoparticles on reduced graphene oxide (rGO) sheets is reported. In the redox reaction, the oxidation state of iron(II) is increased to iron(III) while the graphene oxide (GO) is reduced to rGO. The GO peak is not observed in the X-ray diffraction (XRD) pattern of the nanocomposite, thus providing evidence for the reduction of the GO. The XRD spectra do have peaks that can be attributed to cubic Fe3O4. The field emission scanning electron microscopy (FESEM) images show Fe3O4 nanoparticles uniformly decorating rGO sheets. At a low concentration of Fe2+, there is a significant increase in the intensity of the FESEM images of the resulting rGO sheets. Elemental mapping using energy dispersive X-ray (EDX) analysis shows that these areas have a significant Fe concentration, but no morphological structure could be identified in the image. When the concentration of Fe2+ is increased, the Fe3O4 nanoparticles are formed on the rGO sheets. Separation of the Fe3O4/rGO nanocomposite from the solution could be achieved by applying an external magnetic field, thus demonstrating the magnetic properties of the nanocomposite. The Fe3O4 particle size, magnetic properties, and dispersibility of the nanocomposite could be altered by adjusting the weight ratio of GO to Fe2+ in the starting material.

In this study, we describe a simple, straightforward and scalable method for the preparation of h... more In this study, we describe a simple, straightforward and scalable method for the preparation of high purity reduced graphene oxide/silver (rGO/Ag) nanocomposites via a rapid thermal reduction method. Silver acetate (AgCH3O2) was used as a silver precursor and graphene oxide (GO) served as a substrate for the Ag nanoparticles. The nanocomposites were prepared by grinding GO and the silver precursor, and were rapidly treated at 1000 degrees C in a furnace for 20s under an ambient atmosphere. The obtained rGO/Ag nanocomposites were confirmed by ultraviolet-visible spectroscopy (UV-vis), X-ray diffraction (XRD), and Raman spectroscopy. field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM) images showed uniformly distributed Ag nanoparticles on the reduced GO surface. The average particle size of the formed Ag nanoparticles was 16.9 +/- 3.5 nm. Since the preparation method does not involve any addition of a surfactant or stabilizer, the obtained nanocomposites are of high purity.

We report on the photocatalytic degradation of methylene blue (MB) solution using commercial ZnO ... more We report on the photocatalytic degradation of methylene blue (MB) solution using commercial ZnO and TiO2 (P25) photocatalysts, in the form of slurry and immobilized on glass slides, under ultraviolet (UV) and solar irradiations. The average particle sizes of ZnO and P25 were 100 nm and 30 nm, respectively. Under both the irradiations, the photocatalytic activities of ZnO and P25 slurry resulted in better photocatalytic performance than the immobilized photocatalysts. Interestingly, ZnO showed better degradation capability in comparison to P25 under the solar irradiation. This result revealed that solar light provided a good source of energy to degrade MB in the presence of ZnO. The cyclic voltammetry analysis suggested that the photocatalysts possessed different mechanisms for the degradation of MB. The potential of immobilizing photocatalysts without compromising their performance may lead to easy handling of these materials, resulting in expanding their applications, for example, as a photoanode for photoelectrochemistry.

Silver nanoparticles and silver-graphene oxide nanocomposites were fabricated using a rapid and g... more Silver nanoparticles and silver-graphene oxide nanocomposites were fabricated using a rapid and green microwave irradiation synthesis method. Silver nanoparticles with narrow size distribution were formed under microwave irradiation for both samples. The silver nanoparticles were distributed randomly on the surface of graphene oxide. The Fourier transform infrared and thermogravimetry analysis results showed that the graphene oxide for the AgNP-graphene oxide (AgGO) sample was partially reduced during the in situ synthesis of silver nanoparticles. Both silver nanoparticles and AgGO nanocomposites exhibited stronger antibacterial properties against Gram-negative bacteria (Salmonella typhi and Escherichia coli) than against Gram-positive bacteria (Staphyloccocus aureus and Staphyloccocus epidermidis). The AgGO nanocomposites consisting of approximately 40 wt.% silver can achieve antibacterial performance comparable to that of neat silver nanoparticles.

A stable aqueous suspension of functional graphene oxide/silver nanocomposite (FGO/Ag) was prepar... more A stable aqueous suspension of functional graphene oxide/silver nanocomposite (FGO/Ag) was prepared in an alkaline medium by a simple room temperature stirring method. Functional graphene oxide (FGO) served as substrate, reducing agent and stabilizer for the silver nanoparticles (Ag-NPs). The pH of the solution played a prominent role in the formation of the Ag-NPs. The morphology of the nanoparticles (NPs) could be controlled by adjusting the pH between 9.51 and 12.62 by adding NaOH solution. The aqueous stability of the nanocomposites was greatly improved by the attached functional groups. UV-visible spectroscopy, transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) images suggested the formation of spherical, Ag-NPs with a narrow size distribution at pH 11.40. The nanocomposites showed high bactericidal activity against Escherichia coli bacteria and also enhancement in Raman intensity due to surface enhanced Raman scattering (SERS), which was found to be dependent on the size distribution of the Ag-NPs. This work provides a simple, scalable and environmentally friendly approach to the preparation of a FGO/Ag nanocomposite with promising antibacterial and SERS properties.

This work reports on the investigation of temperature, reaction time, pH, concentration of graphe... more This work reports on the investigation of temperature, reaction time, pH, concentration of graphene oxide (GO) and the effect of gelatin on the synthesis of pyrite structured FeS2 nanoparticles assembled on graphene nanosheets using a facile ‘one-pot’ hydrothermal method. The results of X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy and electron microscopy confirmed the simultaneous formation of pyrite structured FeS2 and the reduction of GO, yielding a nanocomposite of the materials, through the hydrothermal process. The systematic investigation shows that the nanocomposite, comprising a uniform distribution of nanoparticles on the surface of the graphene sheets, is easily synthesized, providing that certain reaction criteria are achieved. The condition warrants that the reaction is carried out in the presence of gelatin with a concentration of 1.5 wt.%/v in a pH of 11 at 200 °C for 24 h. Photocurrent response of the samples showed that the nanocomposite with the GO concentration of 1 mg/mL produced the highest photocurrent value of about 1.01 μA, which is about 2.6 times higher than that obtained by the pure FeS2.

Magnetically separable graphene-Fe2O3/ZnO (G-Fe2O3/ZnO) nanocomposites were prepared by a simple ... more Magnetically separable graphene-Fe2O3/ZnO (G-Fe2O3/ZnO) nanocomposites were prepared by a simple hydrothermal method, using graphene oxide (GO) and Zn(OH)2 as the precursors of graphene and ZnO, respectively and commercially available iron oxide (Fe2O3) as a magnetic material. The nanocomposite materials were characterised by Transmission Electron Microscopy (TEM), Field emission scanning electron microscopy (FESEM), X-ray diffractometry (XRD), Ultraviolet–visible spectroscopy (UV–vis) and Raman spectroscopy. Under natural sunlight, the nanocomposite exhibited excellent photocatalytic degradation of methylene blue (MB). Photoluminescence spectra proved that the high photocatalytic performance of the nanocomposite resulted from the prevention of electron–hole recombination by the effective transfer of electrons between the semiconductors and the graphene. The nanocomposite maintained its ability to degrade MB efficiently, even after 5 cycles of photocatalysis.

Copper oxide (CuO) had been successfully decorated on functionalized graphene (FG) sheets using a... more Copper oxide (CuO) had been successfully decorated on functionalized graphene (FG) sheets using a simple hydrothermal technique. Functionalized graphene oxide (FGO) was used instead of GO as the starting material for the successful preparation of nanocomposites. A series of nanocomposites with varying amounts of FGO was prepared to study the morphological changes of CuO crystals on the FG sheets. X-ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) confirmed the formation of the nanocomposites. The nanocomposite exhibited good catalytic activity towards the degradation of methylene blue (MB). The catalytic performance was improved with the increasing amount of FG due to the enhanced synergy interaction between CuO and FG.

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2009

In the present study, three-dimensional brushite crystals were prepared through palm olein-in-wat... more In the present study, three-dimensional brushite crystals were prepared through palm olein-in-water high internal phase emulsion processing route for the first time. X-ray diffraction patterns revealed that the powders possessed brushite crystalline phase with trace amount of hydroxyapatite. Unique morphologies of the brushite crystals were obtained as a result of tailoring the precursor concentration, surfactant concentration and oil volume fraction. These factors governed the rate of nucleation and crystal growth, resulting in flower-like morphologies. The petal-like flakes grew radially from the centre which gave rise to porosity of less than 2 μm. A plausible mechanism of crystal growth is discussed and postulated schematically. Sodium ampicillin, a broad spectrum antibiotic, was loaded into the pores of the crystals, which was subsequently released in vitro. The controlled release ability for up to 14 days indicated the potential of using these brushite crystals as drug delivery agents for localized treatments. © 2009 Elsevier B.V. All rights reserved.

Journal of Dispersion Science and Technology, 2010

In the present study, olive oil was used for the preparation of three-component high internal pha... more In the present study, olive oil was used for the preparation of three-component high internal phase emulsions with oil volume fraction of more than 0.77 stabilized by palm-based polyoxyethylene lauryl ether for the first time. These emulsions were investigated on their morphology, structural properties, stability, and hydration efficacy. Droplet size distribution observed from the optical micrographs was in agreement with the light scattering results, which suggested that droplet size was influenced by oil phase and surfactant concentrations. Rheological results exhibiting flow curves cross-over implied structural build-up that gave rise to high stability which was supported by stable three-month storage at an elevated temperature. The hydration efficacy of the emulsion was examined in vivo using a corneometer. © Taylor & Francis Group, LLC.

Chemical Engineering Journal, 2008

We report the non-hydrolytic solution phase synthesis of two-dimensional zinc oxide (ZnO) nanopel... more We report the non-hydrolytic solution phase synthesis of two-dimensional zinc oxide (ZnO) nanopellets by using self-made organometallic compound (zinc (II) oleate, Zn(C18H33O2)2) as single precursor. Zn(C18H33O2)2 is prepared by ion exchange reaction between non-toxic fatty acid (palm oil extract) and ion Zn2+. The controlling process of thermal pyrolysis of precursor is carried out under inert argon (Ar) atmosphere. This technique is very effective and reproducible in controlling the shape of ZnO semiconductor nanostructures. The as-synthesized ZnO nanocrystals are found in two-dimensionally well-faceted triangular and hexagonal thin pellet structures. Transmission electron micrograph(s) (TEM) show that the morphologies of ZnO nanopellets can be controlled by annealing duration. X-ray powder diffraction patterns reveal that all the peaks of ZnO nanopellets can be well indexed with standard hexagonal phase of ZnO crystal structure. © 2008 Elsevier B.V. All rights reserved.

Sains Malaysiana, 2010

Titanium dioxide particles were successfully prepared using microemulsion-mediated hydrothermal p... more Titanium dioxide particles were successfully prepared using microemulsion-mediated hydrothermal processing route, with sucrose ester as a stabilising agent. X-ray diffraction patterns revealed that the particles possessed anatase crystal phase. Scanning electron micrographs showed micron-sized spherical particles with rough and smooth surfaces, which eventually interconnected with one another. The formation mechanism of the titanium dioxide microstructures was postulated. The as-prepared particles were subjected to photocatalytic degradation of methylene blue, which exhibited higher photocatalytic activity compared to their commercial counterpart.

Materials Letters, 2004

Nickel sulfide (NiS) nanoparticles were prepared in water-in-oil (w/o) microemulsion system conta... more Nickel sulfide (NiS) nanoparticles were prepared in water-in-oil (w/o) microemulsion system containing sucrose ester as the surfactants. The commercial food grade sucrose monoester (abbreviated S-1170) is a biodegradable and non-toxic surfactant, which can be adopted to form w/o microemulsion system in the presence of 1-butanol as co-solvent. The pseudo-ternary phase diagram for the inverse microemulsion region has been determined by the titration method. It was found that the studied system forms clear and homogenous microemulsion when heated to 37 °C but gradually becomes turbid at room temperature due to the phase separation. The as-prepared NiS nanoparticles were characterized by energy filter transmission electron microscopy (EFTEM), UV-VIS-NIR absorption spectroscopy and X-ray photoelectron spectroscopy (XPS). The results showed that the synthesized nanoparticles have regular shape, monodispersed and in the size range of 3-12 nm. © 2003 Elsevier B.V. All rights reserved.

Materials Letters, 2009

In the present study, we report for the first time the synthesis of ultra small PbS nanorods in a... more In the present study, we report for the first time the synthesis of ultra small PbS nanorods in a non-ionic sugar based water-in-oil (w/o) microemulsion system using food grade sucrose ester as surfactant. PbS was formed by mixing lead nitrate and thioacetamide in the water core of the microemulsion system. The as-prepared PbS nanorods were characterized by X-ray diffractometry (XRD), uv-visible absorption spectroscopy (UV-VIS), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The diameter of the PbS nanorods were found to be extremely small, which is in the range of 2.64 nm to 2.91 nm depending on reaction aging time. Spherical PbS nanoparticles were formed after 12 h and PbS nanorods were formed after more than 1 day of reaction aging time. © 2008 Elsevier B.V. All rights reserved.

Journal of Nanomaterials, 2011

We report the synthesis of In 2 S 3 nanorods in a nonionic sugar-based water-in-oil (w/o) microem... more We report the synthesis of In 2 S 3 nanorods in a nonionic sugar-based water-in-oil (w/o) microemulsion system using food grade sucrose ester as biosurfactant. In 2 S 3 was formed by mixing indium (III) chloride and thioacetamide in the water core of the microemulsion system. The as-prepared yellowish In 2 S 3 was characterized by X-ray diffractometry (XRD), UV-visible absorption spectroscopy (UV-Vis), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FTIR). Formation of spherical or rod-like In 2 S 3 nanomaterials was dependent on reaction time. Rod-like In 2 S 3, arranged in bundles, was formed only after 2 days of reaction time. Upon longer aging time, a mixture of rod-like and spherical In 2 S 3 was formed. A plausible formation mechanism of the In 2 S 3 nanorods in the sucrose ester microemulsion was postulated. The diameter of the In 2 S 3 nanorods was found to be very small, which is 8.97±2.36 nm with aspect ratio of 20:1 (length:diameter). Copyright © 2011 N. M. Huang.

Journal of Crystal Growth, 2004

Copper sulfide nanoparticles were prepared in lyotropic hexagonal phase consisting of poly (oxyet... more Copper sulfide nanoparticles were prepared in lyotropic hexagonal phase consisting of poly (oxyethelene) 5 nonyl phenol ether (NP5), poly (oxyethelene) 10 nonyl phenol ether (NP10), cyclohexane and aqueous solutions. The stability of the hexagonal phase, which was employed as the reaction template, has been determined by polarizing microscopy, small-angle X-ray scattering (SAXS) and rheology measurement. The optical observation showed that the hexagonal phase liquid crystal system still presented the characteristics spherulitic and focal conic texture after the growth reaction. In addition, there was giving no significant changes on the rheological response of the surfactant system after the formation of the copper sulfide nanoparticles. SAXS data showed that the microstructure dimensions of the surfactant aggregates were preserved and not affected by the growth reaction inside the systems. The final products were characterized by energy filter transmission microscopy, energy dispersive X-ray analysis and UV-visible absorption spectroscopy. The results showed that the size and morphology of the nanoparticles obtained were greatly affected by the reaction aging time. The presence of quantum confinement effect was apparent for the resulting nanoparticles as the estimated optical band-gap energy increased markedly with the decrement of the particles size. © 2004 Elsevier B.V. All rights reserved.