北京仪尊时代科技有限公司
北京仪尊时代科技有限公司

界面流变仪应用 Linear Viscoelastic Behavior of End-T

2004-11-12929
行业应用: 石油/化工 化肥

文件大小:127.43KB

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ABSTRACT:We investigate therheological behavior of Langmuir monolayers consisting of polyisoprene chains tethered by one end to the air/water interface. These 10-50 nm thick monolayers provide model systems of a molten polymer brush for which the ends can move within the interface. Their linear viscoelastic properties are determined by applying a small-amplitude shear flow within the interface plane and investigated as a function of surface density and length of tethered chains. When increasing the chain length, we observe a transition from a liquidlike to at ransient network behavior typical of entangled bulk polymer melts. The terminal relaxation time and the effective bulk zero shear viscosity of themonolayers are 2-3 orders of magnitude higher than those of a linear bulk polyisoprene melt of identical molecular weight. Both quantities are shown to exhibit an enhanced molecular weight dependence and to increase with surface density.
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