Advanced Materials Research Vol. 701

Abstract: Fundamentally, ceria particle had ability to store, transport and release oxygen, which was identified as oxygen storage capacity (OSC). Due to this OSC ability, ceria became the most important component in the three-way catalyst. With the addition of zirconia into the ceria resulting in better performance in three-way catalyst as it increased or improved thermal stability and also promotes the redox properties. This study was conducted to investigate the effects of heat treatment on the structure and physical property of nanocrystalline Ce-Zr-O solid solution. Microemulsion method was used for preparation of Ce-Zr-O solid solution, and heat treatment investigation was applied towards the synthesized nanocrystalline Ce-Zr-O solid solution. The phase and crystal structure of Ce-Zr-O solid solution were determined using XRD analysis. While, the modification of surface area and porosity size over the wide range of calcination temperatures range from 300°C to 700°C was investigated using BET Analyzer. XRD analysis confirmed the Ce_0.75Zr_0.25O₂ solid solution was succesfully synthesized in the research. The results exhibited the effect of heat treatment on the decreasing of surface areas and porosity profiles of the Ce_0.75Zr_0.25O₂. Despite of the reduction of surface areas at elevated temperatures, the study found the promising results that the enhancement of thermal stability of ceria by addition of zirconia.

Abstract: Superparamagnetic iron oxide nanoparticles were synthesized using co-precipitation, hydrothermal and ultrasonic routes from Fe²⁺/Fe³⁺ ions and NaOH. The average diameter for the sample prepared using co-precipitation, hydrothermal and ultrasonic method is 33, 9 and 30 nm, respectively with surface area of 85, 117 and 87 m²/g, respectively. Although the results showed all the magnetite nanoparticles were superparamagnetic, but their saturation magnetization and coercitivity are different, depending on the method of synthesis. This study shows that method of synthesis is important that influence the physico-chemical properties of the resulting magnetite iron oxide nanoparticles.

Abstract: The aim of this research was to control the delivery of naproxen from emulsion-based sodium phosphorylated chitosan (PCTS) nanoparticles (PCTS nanoemulsion) by thermal stimulus. The dynamic light scattering and optical microscope results demonstrated that the droplet size of emulsion-based nanoparticles was sensitive to temperature. The PCTS nanoemulsion exhibited the droplet size around 230 nm at 30°C. Emulsion droplets were increased in their size over critical temperature of around 60°C. Besides, the droplet size was reversible to 270 nm when the temperature decreased to 30°C. This indicated that the droplet size of PCTS nanoemulsion was sensitive to thermal stimulus. It might owe to molecular chain extension and rearrangement of PCTS at the interface of emulsion droplets. Therefore, the control release of naproxen from PCTS nanoemulsion via thermal stimulus was investigated. In vitro release study showed that the naproxen was released from PCTS nanoemulsion in high amount over critical temperature. These results indicated that the PCTS nanoemulsion exhibited a potential application as intelligent thermal sensitive drug carrier.

Abstract: The effect of glycerol concentration (15 w/w%, 20 w/w%, 30 w/w% and 40 w/w%) to the flexural and impact properties of plasticized sugar palm starch (SPS) was investigated in this present paper. Prior to the testing, the sugar palm starch extracted from the interior part of sugar palm stem was mixed with common glycerol (was used as a plasticizer) to form a novel biopolymer. The flexural and impact test were carried out according to ASTM D790 and ASTM 256 respectively. From this investigation, it is found that the 30% glycerol concentrated SPS biopolymer showed the highest flexural strength and flexural modulus with the value of 0.13 MPa and 87.54 MPa respectively. For the impact analysis, it is also found that same biopolymer showed the highest impact strength which is 6.13kJ/m².

Abstract: Cellulose-enrich residue from corn husk was transformed into biodegradable plastic films. After chemical removal of lignin and bleaching the corn husk pulp with hydrogen peroxide, corn husk cellulose powder was received by acid hydrolysis. The esterification of corn husk cellulose was performed using lauroyl chloride as an esterifying agent, toluene and pyridine as solvent and catalyst, respectively. The optimum conditions for esterification were investigated in terms of reaction time and temperature. Chemical structure and solubility of modified cellulose were examined. Cellulose laurate film was obtained by casting method in chloroform solvent. The tensile strength and elongation at break of cellulose laurate film were 5.15 MPa and 6.55%, respectively. The biodegradable of cellulose laurate films in different disposal environments including landfill and wastewater treatment plant for 2 months were investigated. The biodegradation process was followed by measuring the changes in the physical appearance and tensile properties of the films.

Abstract: The use of reduction and nucleation technologies in nanosize active pharmaceutical ingredient (API) is as an enabling to bring improved drug products to the marketplace demand as well as for improved drug delivery. nanoPharmaceutical field represents a hopeful set of pharmaceutical materials offering the prospect of better alternatives to optimize drug physical properties and biopharmaceutical issues such as solubility, stability and bioavailability in pharmaceutical development without changing the chemical composition of the API, thereby, giving new patentable solid forms. With physically improved solid API may impact the the pharmaceutical intellectual property landscape. Nanoparticle formation is achievable in many ways, although primarily through particle reduction or through manipulation of the nucleation mechanism. Keywords: active pharmaceutical ingredient; drug delivery; ultra rapid freezing.

Abstract: The tensile properties of untreated and alkali treated betel nut husk fiber were investigated using single fiber tensile test method and the fiber structures were observed using SEM technique. The alkali treatment aids in the removal of lignin, hemicellullose and non-cellulosic components such as wax and pectin on the betel nut husk fiber surface, which yields bigger lumen size and rougher betel nut husk fiber surface. The alkali treatment enhanced the elongation at break of betel nut husk fiber but at the expense of tensile strength and Young's modulus.

Abstract: Over the last decade, there has been increasing research interest in the value of biosourced materials from lignocellulosic biomass. Abundant sources of lignocellulosic biomass such as palm, napier grass, luceana tree, urban waste, municipal solid waste, agricultural waste and other waste have the potential to become a sustainable source of biofuel. In Malaysia, dissolution of cellulose from palm biomass to produce ethanol as future biofuels is very promising since palm residues from palm industry are highly abundant. In addition, cellulose contents in palm wastes or residues are relatively high for instance from empty fruit bunch or palm trunk. An efficient pretreatment is highly required prior to processes which convert the lignocellulosic palm biomass to bioethanol. The kinds of processes needed nowadays are called as green technology based techniques which are environmental friendly. Various solvents have been applied to dissolve cellulose including various types of ionic liquid as well. Previously, other method such as acid hydrolysis pretreatment process cause many drawbacks due to their low rates of hydrolysis and extreme acidic conditions. The dissolution process of the lignocellulosic biomass with ionic liquids is at its better advantage due to better dissolution as compared to by using organic or inorganic solvents. Therefore, at the moment, ionic liquid is becoming more preferable in dissolving the lignocellulosic biomass or any palm residues for instance.

Abstract: The energy efficiency of microwave irradiation for bioethanol production from sago bark waste (SBW) was studied. The maximum sugar yield of 62.6 % was reached at the biomass loading 20% (w/w). The high ethanol yield of 60.2% theoretical yield, ethanol concentration 30.67 g/l was achieved by diluted sulfuric acid supported microwave irradiation with 40% (w/w) biomass loading at 60 h fermentation. The energy consumption of microwave irradiation to produce 1 g sugar and 1 g ethanol was calculated separately. The lowest energy consumption was noticed while biomass loading and energy input were fixed at 40 % (w/w) and 33 kJ (1100 W for 30 s) respectively, and it is amounted to 1.27 and 1.76 kJ to produce 1 g of sugar after enzymatic hydrolysis and 1 g ethanol after fermentation, individually. Usually, 1 g ethanol can produce approximately 27 kJ of energy, and therefore, the energy input for the microwave pretreatment was only 7% of the energy output. The microwave irradiation technique established for SBW to produce ethanol succeeded in 80% energy savings for producing 1 g ethanol compared to rape straw by microwave pretreatment previously reported.

Abstract: Poly (lactic acid) (PLA)/polyethylene oxide (PEO) bicomponent fibers werefabricated by co-electrospinning technique in a side by side configuration. Effect of PEO concentration, PLA and PEO solution flow rate and an applied voltage on formation, size and morphology of the fibers were investigated. The results showed that the fibers size increased with increasing PEO concentration, PEO flow rate ratio and applied voltage. The composition of the fibers was confirmed by IR spectrum. Additionally, by pairing PEO, which is a water soluble polymer, with PLA, follow by PEO phase removal in water, a C-shaped ultrafine fiber was prepared.