在宏观对齐的电聚合物纳米纤维中,电场诱导的聚合物链的方向
Meghana V Kakade1, Steven Givens, Kenncorwin Gardner
1Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, USA.
Journal of the American Chemical Society
|February 17, 2007
概括
在电旋过程中,电场将纳米纤维内的聚合物链对齐. 这种分子导向为医学和电子行业的先进应用创造了异构性质.
科学领域:
- 材料科学 材料科学 材料科学
- 聚合物科学 聚合物科学
- 纳米技术 纳米技术
背景情况:
- 电是一种用于制造聚合物纳米纤维的常见方法.
- 控制纳米纤维中的分子导向对于先进的材料特性至关重要.
研究的目的:
- 调查用于聚合物纳米纤维宏观对齐的电场是否也可以诱导与纤维轴平行的分子链对齐.
- 展示一种创造具有异构性质的单轴定向聚合物纳米纤维的方法.
主要方法:
- 垂直电,带有电场诱导的静止收集器.
- 极化里叶变换红外光谱 (FTIR) 用于分子导向分析.
- 用于结构性表征的极化拉曼散射.
- 用X射线衍射 (XRD) 验证分子方向.
主要成果:
- 证明了电旋过程中的电场将聚合物链与纳米纤维轴平行对齐.
- 实现了聚合物纳米纤维的宏观对齐和同时的分子导向.
- 使用三个独立的光谱和衍射技术验证了分子方向.
结论:
- 电场辅助电是一种有效的方法,可以在聚合物纳米纤维中诱导分子导向.
- 单轴定向的纳米纤维具有适用于生物医学,微电子和光学的异构性质.
- 该技术为设计具有定制功能的先进纳米材料提供了一条途径.
相关概念视频
01:29Induced Electric Dipoles
A permanent electric dipole orients itself along an external electric field. This rotation can be quantified by defining the potential energy because the external torque does work in rotating it. Then, the potential energy is minimum at the parallel configuration and maximum at the antiparallel configuration. While the former is a stable equilibrium, the latter is an unstable equilibrium.
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
01:27π Electron Effects on Chemical Shift: Overview
An applied magnetic field causes loosely bound π-electrons in organic molecules to circulate, producing a local or induced diamagnetic field over a large spatial volume. As the molecules tumble in solution, the field generated by π-electrons in spherical substituents results in a zero net field. However, the net field generated by π-electrons in non-spherical substituents is not zero. The effect of this induced field depends on the orientation of the molecule with respect to B0, resulting in...