Abstract: Cadmium based quantum dots (Cd QDs) is well established and extensively used for various applications, but found limiting usage in bioimaging application, due to its high toxicity and insolubility in aqueous solution. Passivation and/or encapsulation of the Cd QDs with a non-toxic and biocompatible polymer are common practice to overcome the drawback. In our work, CdSe is synthesized as a core and encapsulated with ZnS to produce a hydrophobic colloidal core/shell CdSe/ZnS QD. Then, a biocompatible PEGylated amphiphilic polymer as matrices is used to encapsulate CdSe/ZnS QD for converting it into water dispersible property which required for in-vitro imaging applications. The cell viability and cellular uptake of the biocomposite were studied against cancerous and non-cancerous cells. Also, peak of emission spectrum was recorded to determine the photostability of this biocomposites under continuous UV light illumination up to 100 minutes.
Abstract: High-strength magnesium alloy (AZ31) reinforced poly-lactic acid (PLA) composite rods for potential application of bone fracture fixation prepared by plastic injection process on Mg rod.Thecomposities possess improved the interfacial bonding between poly-lactic acid and Mg rod due to the micro-anchoring which lead to better mechanical performance in Simulated body fluid solution.The present results indicated that this new PLA-clad Mg composite rods show good potential for biomedical applications.
Abstract: Silicone rubber is widely used in various fields but has low strength, whereas kenaf has higher strength. Therefore, this study aims to synthesise a new material that consists of both kenaf and silicone with three different variances and determine its properties using the three most common hyperelastic constitutive models: Neo-Hookean, Mooney-Rivlin and Ogden. In order to obtain the material constant of kenaf silicone biocomposite, experimental and numerical approaches are adapted. The xperimental approach involves synthesising of kenaf silicone biocomposite and uniaxial tensile test, while the numerical approach involves curve fitting method using an excel programme. Curve fitting method was used because the raw data from tensile test alone could not determine the material constant of agar silicone biocomposite. The results show that the numerical value of the material constant increases as the percentage of the reinforcement material (kenaf) increases. However, the tensile strength of the material decreases as the reinforcement material increases.
Abstract: This paper will report the fabrication process and microstructure analysis of fibrous composite incorporating ultra-high molecular weight polyethylene (UHMWPE) fabric, electrospun polycaprolactone (PCL), and bioglass particles. Briefly, electrospinning was performed to form PCL fibre lamination in the surface of UHMWPE fabric. This UHMWPE/PCL material was then bioglass-coated. Sequentially, microstructure of the UHMWPE fabric, UHMWPE/PCL, and UHMWPE/PCL/bioglass was imaged and analysed. The composite showed aligned ultrafine PCL fibres and distribution of bioglass particles in the layer of electrospun PCL. The results of this study provide groundwork for more advanced investigation, as well as development of implant prototype.
Abstract: This study aims to examine mechanical properties of biocomposites formulated with virgin/recycled acrylonitrile butadiene styrene (ABS). Neat virgin ABS (VABS), neat recycled ABS (RABS), VABS with 15% palm long fiber (VABS/15PLF), and RABS with 10% palm short fiber (RABS/10PLF) were fabricated and examined. Twin extruder machine was used to manufacture granular composite. Impact, tensile, and hardness tests were carried out. This study found that the incorporating palm fiber into the matrix polymer increased brittleness of the composites. Impact strength of the composites increases with the rise filler loadings. Increasing filler loading in VABS was found to be able to increase the composite hardness. Conversely, for RABS, the composite hardness was found to decrease with the rise filler loadings.
Abstract: Multi-walled carbon nanotube-zirconia composite (MWNT-ZrO2) was synthesized by a simple in situ chemical precipitation method. Adsorption of bovine serum albumin (BSA) from aqueous solution on the MWNT-ZrO2 composite was studied using batch technique at different pH and temperatures. The adsorption equilibrium and kinetic data were analzed using different models. The adsorption isotherm data could be described by both of the Langmuir and Freundlich adsorption models. Adsorption kinetics followed the pseudo-first-order rate model. MWNT loading improved the surface and the BSA adsorptive characteristics of zirconia.
Abstract: The different amount of hydrophilic hydroxyl group, including 3, 5, 7 and 10 wt.% copoly (styrene-co - divinyl benzene – co - 2-hydroxylethylenemethacrylate) (poly (St- co -DVB- co -HEMA) s) nanoparticles were synthesized via microemulsion polymerization in the present paper. The average size of the poly (St-co-DVB-co-HEMA) s was ca. 44 nm after zetasizer (DLS) measurement and SEM observation. The characteristic peaks at 3200 ~3600 cm-1 in FTIR was assigned at hydroxyl group of HEMA unit. The NBR/poly (St-co-DVB-co-HEMA) s composites films with 250 μm thickness were prepared simply via latex mixing and followed by spinning coating. The mechanical properties of the poly (St-co-DVB-co-HEMA) s/rubber nanocomposites, including the tensile strength, modulus and elongation, were increased with that of increasing of poly (St-co-DVB-co-HEMA) s adding. In addition, as the poly (St-co-DVB-co-HEMA) s nanoparticles carried out with constant St/HEMA molar ratio of 97:3 and the DVB content in 10 wt.%, the elongation at break that up to more than 3500% and the ultimate stress increased from 0.2 MPa to 0.6 MPa. The poly (St-co-DVB-co-HEMA) s nanoparticles prepared by emulsion polymerization could be successfully enhanced the mechanical properties of rubber latex.
Abstract: The high interest in the synthesis of mesoporous catalyst demands that novel materials are developed with simple methods capable of improving process yields. In this work, a novel heterogeneous mesoporous catalyst support has been synthesized using mesoporous SBA-15 loaded with mixed bimetal oxides of CeO2 and MgO. Formation of the SBA-15 was actuated in air at room temperature (25°C) and in oven conditions at 100°C after which cerium nitrate and magnesium nitrate precursors were then impregnated into the SBA-15 framework and calcined at 550°C for each of the air and oven crystallization processes. XRD peak patterns confirmed SBA-15 formation and dispersion of nanocrystallites of CeO2 and MgO within the porous framework of SBA-15. Both the air and oven dried processes produced mesoporous MgO-CeO2/SBA-15 catalysts with isotherms that exhibit typical H1 type hysteresis confirming that they possess open-ended cylindrical mesopores. The structural data extracted gave average pore size, pore volume and surface area values in the ranges of 3-5.2 nm, 0.600-2.500 cc/g and 400-500 m2/g respectively which is ideal for several industrial applications.
Abstract: This report deals with a simple and efficient method to develop hybrid carbon nanoparticles (Nps) employing Multi-walled carbon nanotubes (MWCNTs) and Fullerene nps. Fullerene nps were self-assembled via Ultrasonicated Liquid-Liquid Precipitation. Surface treated MWCNTs were entangled with fullerene nps during the process of assembling of the fullerene nps. Fullerene nps are formed by reaction between two solutions, one is the saturated solution which contains dissolved fullerene and other solution is a rough alcohol. This reaction increases the concentration of carbon in the solution and leads to super saturate hence self-assembling into nanoparticles. The obtained hybrid nanoparticles sizes were in the range of 100 nm to 300 nm with entangled mwcnts and were confirmed by characterization using SEM, Raman, UV-Vis, XRD, and DLS.