Advanced Materials Research Vol. 1133

Abstract: High surface area Ag/ZnO with an average diameter of 13.95 nm was successfully synthesized through a facile route, using ascorbic acid and silica rice husk as reducing agent and amorphous support respectively. This nanomaterial was characterized by transmission electron microscopy, N₂ adsorption-desorption, atomic absorption spectrometry and particle size analyzer. This simple method resulted in the production of almost spherical Ag/ZnO nanoparticles with high BET surface area and large pore volume of 341.46 m²g^-1 and 0.59 cm³g^-1 respectively. This preliminary study revealed the successful inclusion of metal cations into the silica framework without damaging the mesoporosity nature of silica.

Abstract: Carbon nanotube has been successfully grafted on the surface of spherical silica gel via floating-catalyst chemical vapour deposition method. The growth conditions were set to be 3 hours growth time and 5 wt. % of ferrocene catalyst (dissolved in toluene) injected into the furnace at a rate of 0.04 ml/min. It was found that the reaction temperature of 760°C yields the best quality hybrid particles. Decreasing and increasing the reaction temperature resulted in the formation of product that consists of thicker tubes, higher defects as analysed by Raman, as well as least carbon formation.

Abstract: A sol-gel technique has been used to synthesize silver decorated silica nanospheres for surface enhanced Raman scattering (SERS) substrates. X- Ray diffraction (XRD) spectra shows peak at 2θ = 38.1, 44.6, 64.7, and 77.5^° confirming the presence of Ag nanoparticles on the substrates. The Ag- decorated silica nanospheres were applied as SERS substrates using Rhodamine 6G (R6G) as probe molecule. From Raman analysis, the highest SERS enhancement factor at R6G concentration of 10² was calculated around ~10¹⁰.

Abstract: Mass production of GO has always been an issue. Generally, there are 3 general methods available, namely Brodie’s, Staudenmaier’s and Hummer’s Method. These three methods differ in the type of oxidation agents used. There are plenty of developed methods to produce GO were reported in the literature including the improved Hummer’s method. This method is associated with the use of mixture of sulphuric acid/phosphoric acid (H2SO4/H3PO4) in 9:1 ratio without the presence of sodium nitrate (NaNO3).The amount of potassium permanganate (KMnO4) was set at 9.0g. This method allows high yield and ease of control. In this reaction, one of the important indicators was the colour changes during the addition of hydrogen peroxide (H2O2) into the mixture. However, with the large amount of KMnO4 added, the colour change was hardly observed. Therefore, one possible way to cope with that was to vary the amount of added KMnO4. Subsequently, the produced GO were characterized by X-Ray diffraction (XRD) and scanning electron microscope (SEM).

Abstract: This article studies the thermal properties of multi-walled carbon nanotubes (MWCNT) reinforced polylactic acid (PLA)/liquid natural rubber (LNR) blends which prepared via melt blending method. Various percentages (0.5, 1.5, 2.5, 3.5 and 4 wt%) of MWCNT were added into PLA/LNR blend. TGA shows that the addition of MWCNT into PLA/LNR blends helps to improve thermal stability of the PLA/LNR/MWCNT nanocomposites. DSC shows that the glass transition temperature increased when 0.5%, 1.5%, 2.5% and 3.5% of MWCNT was added to the PLA/LNR blend. The cold crystallization and melting temperature were reduced when MWCNT was added in the PLA/LNR blend systems. The SEM micrographs confirm the effect of good dispersion of 3.5wt% of MWCNT in PLA/LNR blend helps to promote well combined MWCNT-matrix networks and generate the synergistic effect of the system which is improved the thermal properties significantly.

Abstract: Nearly 40% of the world gas reservoir contains high level of CO₂ that stance problems to development. The discovery of natural gas field with CO₂ content of as high as 87% in Malaysia poses new challenges in terms of the CO₂ separation processes. This research work investigates the potential of MIL(Materials Institute Lavoisier)-101 as CO₂ capture and storage candidate by conducting an experiment with different pressure between the synthesised and modified MIL-101 using Multi-wall carbon nano tubes (MWCNTs). To investigate the effect of the MWCNTs in MIL-101 towards CO₂ adsorption performance. The synthesized MOFs were characterized using scanning electron microscopy (SEM) for surface morphology, Thermogravimetric analysis (TGA) for thermal stability, X-ray diffraction (XRD) for crystals plane, Brunauer-Emmet-Teller (BET) for surface area and CO₂ adsorption performance. The result had showed that the modified MIL-101 enhanced the CO₂ adsorption compared to the pure MIL-101. MWCNT@MIL-101 showed the adsorption of CO₂ uptake is 0.0029mmole^-1/g at 100kPa.

Abstract: This paper presents effects of Colloidal Nano Silica (CNS) as a Viscous Modifying Agent (VMA) on fresh properties of self-compacting concrete (SCC) containing high volume ground Palm Oil Fuel Ash (POFA). Accordingly, fresh properties of the SCC were tested using slump flow, J ring, L-box, and sieve stability test. To monitor the viscous behaviour of the fresh SCC with CNS, fillingability and passingability parameters were maintained within a desirable performance criterion whilst segregation, cohesiveness, and superplasticizer demand were the variables. All the mixtures were designed with the water/binder ratio of 0.45 and a total binder content of 500 kg/m³. The results revealed that the inclusion of CNS decreased the segregation and augmented the cohesion in all mixes.

Abstract: Addition of nanosized particles as an additive to the fluid in order to improve the properties of fluid has gained much attention in recent era. Limited studies are reported in literature for the preparation and estimation of thermophysical properties of nanofluids based on binary mixture of liquids. Thermophysical properties of nanofluids including effective density and effective viscosity of alumina nanoparticles based nanofluids are measured at a temperature range of 20-60°C. The study is carried out in binary mixture of ethanol and water at different concentrations. Alumina nanoparticles of 50 nm are used at different particle loading i.e. 0-0.3 wt% in different proportions of ethanol and water. The analysis of measured experimental values indicates that the addition of nanoparticles in different concentrations has significant effect on the effective density and the effective viscosity of fluids. The predicted values are estimated from correlation coefficients as a function of temperature.

Abstract: In this paper, TiO₂ nanotubes (TNTs) were synthesized through simple chemical hydrothermal treatment process when anatase TiO₂ nanopowder is chemically treated with 10 M NaOH and >99.5% ethanol at 180°C for 24 hr. According to the transmission electron microscopic (TEM) image analysis TNTs tubes were formed in the length sizes from 400 to 700 nm with inner diameter of 5 nm and outer diameter of 8 nm. The morphological and structural properties of synthesized TNTs was characterized by powder X-ray diffraction (XRD), thermal gravimetric analysis (TGA), UV–Vis diffuse reflectance spectra (DRS).

Abstract: The aim of this study was to study the morphology and structural characteristic of NCC hydrolyzed from filter paper. The NCCs were extracted by acid hydrolysis at 50°C for 1 hour, using 55% conc. H₂SO₄ under vigorous mechanical stirring, centrifugation at 12000 rpm in distillate water and followed by homogenizing at 7000 rpm. The morphology and surface profiles of the NCC suspension was characterized using field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM). The crystalline structure of the NCC was evaluated by using X-ray diffraction (XRD) technique. As a result, hydrolysed NCC was found to have a rod liked shape with diameter in the range of 100-300nm length and 10-50nm width, with the aspect ratio value of 10.3 nm. According to XRD investigations, the semi-crystalline cellulose was observed with the presence of an amorphous broad hump and crystalline peaks at 2θ of 15^o and 22.7^o, respectively. The crystalinity index of the raw filter paper was calculated as 86.7 % and increased to 94.4 % as it was extracted to NCC. Crystallite size of raw filter paper and NCC was calculated as 20.6 nm and 11.4 nm, respectively