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Gradient Materials (gradient + material)
Selected AbstractsA New Technique for Preparing a Filled Type of Polymeric Gradient MaterialMACROMOLECULAR MATERIALS & ENGINEERING, Issue 11 2006Yong-Bin Zhu Abstract Summary: So-called functionally gradient materials have received increased attention as a new type of composite whose microelements, including composition and structure, change spatially to optimize the gradient properties for a specific application. In this study, a new technique for continuously preparing a filled type of PGM was investigated through co-extrusion/gradient distribution/2-dimensional mixing with conventional polymeric material processing facilities. The processing line from co-extrusion, gradient distribution to 2-dimensional mixing was fulfilled by two extruders, a gradient distribution unit and 2-dimensional mixing units. The gradient distribution unit and 2-dimensional mixing units were designed separately in our group. As an example, a PE/GB PGM was prepared by using this new technique. The gradient variation of composition along the sample thickness direction was studied by TG and SEM. The TG results indicated that a gradient variation of the content of GB was formed along the thickness of the sample. The direct gradient distribution of GB came from SEM observation, which showed an increased stacking density of GB along the sample thickness. Experimental results indicated that the processing method with co-extrusion/gradient distribution/2-dimensional mixing can serve as a new way to produce a filled type of PGM and is worthy of further investigation. The prepared polyethylene/glass bead PGM; the graph illustrates the glass bead concentration gradient across the sample thickness. [source] Microchip isoelectric focusing with monolithic immobilized pH gradient materials for proteins separationELECTROPHORESIS, Issue 23 2009Yu Liang Abstract Monolithic immobilized pH gradient (M-IPG) materials were prepared in microchannles by photoinitiated polymerization of acrylamide, glycidylmethacrylate and Bis, followed by the attachment of focused Ampholine onto the surface of porous monoliths via epoxide groups. With M-IPG materials as matrix, FITC-labeled ribonuclease B, myoglobin and ,-casein were well separated by microchip isoelectric focusing (,CIEF) without carrier amphocytes (CAs) added in the buffer. Both chemical and pressure mobilization were applied to drive focused zones for LIF detection. Our experimental results showed that pressure mobilization was preferable with neglectable band broadening, and good peak shape and high detection sensitivity were obtained. All these results demonstrate that ,CIEF with M-IPG materials is not only an efficient mode for protein enrichment and separation but also attractive to couple with other CE modes to achieve multi-dimensional separation or MS for further identification, without the interference of mobile CAs. [source] Fracture Toughness Enhancement for Alumina Systems: A ReviewINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 3 2008Osayande L. Ighodaro Investigations have been carried out to determine ways of tailoring ceramic materials in order that one or more toughening mechanisms are activated in service. Microstructural manipulations, as well as composite formulations involving metallic, intermetallics, and ceramic phases have been used with ceramic matrices. Macrostructurally, laminated structures and functional gradient materials (FGMs) have also been formulated to enhance mechanical properties. Although significant improvements in material properties have been reported, ceramics are still below their projected positions on the materials map. This article presents a review of research activities pursuant to improving fracture toughness of alumina matrix systems and the enhancements achieved. [source] A New Technique for Preparing a Filled Type of Polymeric Gradient MaterialMACROMOLECULAR MATERIALS & ENGINEERING, Issue 11 2006Yong-Bin Zhu Abstract Summary: So-called functionally gradient materials have received increased attention as a new type of composite whose microelements, including composition and structure, change spatially to optimize the gradient properties for a specific application. In this study, a new technique for continuously preparing a filled type of PGM was investigated through co-extrusion/gradient distribution/2-dimensional mixing with conventional polymeric material processing facilities. The processing line from co-extrusion, gradient distribution to 2-dimensional mixing was fulfilled by two extruders, a gradient distribution unit and 2-dimensional mixing units. The gradient distribution unit and 2-dimensional mixing units were designed separately in our group. As an example, a PE/GB PGM was prepared by using this new technique. The gradient variation of composition along the sample thickness direction was studied by TG and SEM. The TG results indicated that a gradient variation of the content of GB was formed along the thickness of the sample. The direct gradient distribution of GB came from SEM observation, which showed an increased stacking density of GB along the sample thickness. Experimental results indicated that the processing method with co-extrusion/gradient distribution/2-dimensional mixing can serve as a new way to produce a filled type of PGM and is worthy of further investigation. The prepared polyethylene/glass bead PGM; the graph illustrates the glass bead concentration gradient across the sample thickness. [source] | ||||||||||