Advanced Materials Research Vols. 1044-1045

Abstract: A dual-core photonic crystal fiber (PCF) with high birefringence, short coupling length and broadband flat dispersion is proposed in the paper. The symmetry of the original symmetric structure composed of hexagonally distributed air holes is distorted by replacing the innermost 12 air holes with 6 elliptical air holes. The characteristics of the dual-core PCF such as birefringence, coupling length and chromatic dispersion are analyzed by tuning its structural parameters. The results demonstrated that the dual-core PCF exhibits simultaneously a birefringence of up to 10^-2, a coupling length of 68.178 for the x-polarization and 74.825 for the y-polarization, and a broadband flat dispersion ranging from 1.1 to 1.6. The novel dual-core PCF may find applications in polarization-maintaining fibers and fiber-based polarization beam splitters/couplers with broadband flat dispersion.

Abstract: With the development of human civilization progress and the improvement of people's living standard, people's clothing, jewelry demand is higher and higher, in this environment, the textile industry also got a boost of, now, all countries in the world in research and development of new fiber material, and use it as indicators of economic development and progress, this study of the application of new type fiber materials in knitting clothing industry has carried on the simple discussion.

Abstract: Mimosa pudica and Phyllanthus niruri were used as the traditional medicines in Thailand. Both plants were very useful for various pharmacological and biological activities. In the present study, the bioactivities of Mimosa pudica and Phyllanthus niruri extracts were investigated. The amounts of total phenolic compounds were analyzed using gallic acid as standard compound and the antioxidant activities were evaluated using ABTS assay. The phenolic content of Mimosa pudica extracts revealed that AEE1 contained the maximum phenolic content and that of Phyllanthus niruri extracts exhibited the same result of maximum phenolic content in AEE2. The antioxidant activity were performed and found that WE1 from Mimosa pudica and WE2 from Phyllanthus niruri exhibited prominent ABTS radical scavenging activities. Interestingly, AEE1, AEE2 and EAE2 specifically exhibited the high cytotoxicity against the colon cancer cell line (SE620).

Abstract: Massive production of Portland cement through mining process imposes detrimental effects on environment. Utilization of industrial and agricultural wastes as alternative raw materials for cement production, thus, has a pronounced positive impact on human quality of life. This study aimed at synthesizing constituents that exist in Portland cement by the solution combustion technique. Cockleshell, rice husk ash, and alumina wastes were used as initial reagents for the synthesis. Compositional analysis of the synthesized powders exhibited desired phases of dicalcium silicate, tricalcium silicate, and tricalcium aluminate. Compositional and microstructural analyses of the specimens cast from combusted powders revealed similar features compared with Portland cement. Ettringite, calcium hydroxide, and calcium silicate hydrate were prominent phases observed from both compositional and microstructural analyses.

Abstract: In this work, the effect of ZnO nanoparticles as activator is studied in unfilled natural rubber and compared with conventional ZnO on cure characteristics and mechanical properties. ZnO nanoparticles are synthesized by precipitation method using zinc nitrate tetrahydrate and sodium hydroxide as precursor. Particle size of ZnO nanoparticles can be controlled by polymeric additive. It is found that the average primary size of synthesized ZnO nanoparticles around 28.71 nm and the specific surface area around 31.45 m²/g. The crystalline structure exhibits hexagonal structure with wurtzite. The rheological properties of unfilled natural rubber show that the maximum torque (M_H) and the optimum cure time (t₉₀) increase with increasing synthesized ZnO nanoparticles loading. The minimum torque (M_L) of unfilled natural rubber which uses synthesized ZnO nanoparticles loading higher than conventional ZnO. Compression set and tension set are the permanent deformation also investigated. It is found that deformation reduces when increase synthesized ZnO nanoparticles loading. The mechanical properties such as hardness, tensile strength, 100% and 300% modulus, tear strength, elongation at break are improved, without detrimental effect on properties. For unfilled natural rubber, synthesized ZnO nanoparticles can be reduced successfully from 5 to 2 phr and stearic acid 1 to 0.3 phr, respectively.

Abstract: Polycarbonate/Multi-wall Carbon Nanotubes (PC/MWCNT) nanocomposites with 0.55% and 0.77% of MWCNT were prepared by twin-screw compounding extruder. The morphology and dispersion were characterized by SEM. The Raman analysis confirmed the good interaction between carbon nanotubes (CNTs) and Polycarbonate (PC). The TGA result showed that the PC/MWCNT nanocomposites degraded in two time extrusion (TTE) as compared to one time extrusion (OTE), which was attributed to the temperature effect. Inspite of degradation, TTE nanocomposite showed good dispersion of MWCNT in PC.

Abstract: Fused Deposition Modelling (FDM) of thermoplastic materials is generally a well-known technology among all additive manufacturing (AM) technologies and therefore, it is essential to investigate the mechanical properties of such FDM processed materials. Several open-source and low cost AM machines, known as 3D Printers, have recently been developed using thermoplastic extrusion process based on the original FDM technology. Many of these 3D Printers use Polylactic Acid (PLA) plastic for building parts. The main objective of this paper is to investigate the tensile properties of the PLA thermoplastic material processed by the Cube-2 3D Printer. In this study, the dog-bone sized PLA specimens are printed in different build orientations and a Zwick Z010 tensile testing machine is used to determine the tensile properties of PLA in different build orientation.

Abstract: This research will thus try to broaden the properties of bioplastics to be used as smart materials. Cellulose nanowhiskers will be initially prepared from different cellulose source and its morphology will be investigated. Water-activated shape memories nanocomposites will be consequently prepared from the obtained cellulose nanowhiskers and three polymers those are PBS and PBAT. The mechanical, physical and morphological will be investigated. The influences of cellulose nanowhiskers and their morphology on water-activated shape memory behavior will be studied.Recently, natural fiber have extensively used as reinforcement materials in polymeric nanocomposite due to environment concerns. Cellulose nanowhisker (CNWs) have also attracted much attention as environmentally friendly nanofillers for polymer composites. Cellulose nanowhiskers were extracted from commercial source, paper filter and alpha cellulose, using acid hydrolysis by sulfuric acid with various hydrolysis times (20,45,70,95,120 minutes), temperature (35,45,60°C). The hydrolyzed cellulose was neutralized with two different techniques, dialysis and titration. The samples were then sonicated and dried with a freeze dryer. The effects of preparation conditions on the morphological of cellulose nanowhisker were investigated. Cellulose nanowhisker powders were characterized scanning electron microscopy (SEM) and transmission electron microscope (TEM). The results showed that it was possible to obtain ultrathin cellulose nanowhiskers with diameters as low as 9 nm. A possible correlation between preparation conditions and particle size was not observed but titration technique time process was reduced.

Abstract: Conducting poly (3, 4-ethylenedioxy-thiophene) (PEDOT) thin film was prepared onto gold electrode by electrodepositing from aqueous electrolyte. Glucose oxidase (Gox) was further immobilized on the PEDOT/Au by physical adsorption. The morphology the modified electrode was investigated by FE-SEM. In phosphate buffer medium (0.1mol·L^-1 pH 5.5), cyclic voltmetric results indicated that GOx can be immobilized on the PEDOT film, and the biological activation of GOx was retained. A direct electron transfer was found between immobilized GOx and electrode, which suggested that the PEDOT film could not only supply a platform for enzyme immobilization but also offer a effectively electrical contact with the active sites of enzyme.