A method for preparing multiple sucrose gradients by quickly freezing layers of sucrose has been developed. These gradients may be stored in the freezer indefinitely, and thawed from 8 to 24 h at 4°C before use. The middle region of the resulting sucrose gradients was linear. Thawing time and centri
A New Technique for Preparing a Filled Type of Polymeric Gradient Material
✍ Scribed by Yong-Bin Zhu; Nan-ying Ning; Yang Sun; Qin Zhang; Qiang Fu
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 461 KB
- Volume
- 291
- Category
- Article
- ISSN
- 1438-7492
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✦ Synopsis
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.
magnified imageThe prepared polyethylene/glass bead PGM; the graph illustrates the glass bead concentration gradient across the sample thickness.
📜 SIMILAR VOLUMES
06(2)-. V = 3564(2) A', Z = 4, psnicd = 1.223 Mgm-', F(O00) =1392. E.(Mo,,) = 0.71073 A, p(MoKa) = 0.081 mm-'. T = 153.0(20)K. Data were collected on d Stoe-Siemens diffractometer in the range 8 ' S 20 I 50-(6793 reflections collected, 4926 independent reflections). The structure was solved by direc