EAGER: Confined Self Assembly of Fully Conjugated Rod-Rod Diblock Copolymers in Nanofibers

EAGER：纳米纤维中完全共轭棒-棒二嵌段共聚物的受限自组装

• 批准号: 1144376
• 负责人: Vibha Kalra
• 金额: $ 11.59万
• 依托单位: Drexel University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-10-01 至 2014-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1144376&HistoricalAwards=false
• 关键词: EAGER; Confined; Self; Assembly; Fully; EAGER; Confined; Self; Assembly; Fully

This EArly-concept Grant for Exploratory Research (EAGER) provides funding to study the confined self assembly in nanofibers of fully conjugated rod-rod diblock copolymers. Nanofibers will be fabricated via a process called electrospinning that uses a strong electric field to elongate and thin a polymer solution jet enabling the formation of fibers with near nanoscale diameters (50-500 nm). Rod-rod block copolymers combine the physics of liquid crystalline ordering of rod-like polymers (at the length scale of 1-10 nm) and microphase-separation of coil-coil block copolymers (at length scale of 10-100 nm) with the potential of forming hierarchically ordered materials. The effects of solvent evaporation rate and extensional deformation (during electrospinning) on self assembly structures at both length scales will be studied. The assembly in nanofibers will be characterized using transmission electron microscopy as well as small and wide angle x-ray scattering. Similar studies on self assembly in solution-cast films will be conducted as reference. If successful, this work will provide a novel active material for the design of high efficiency organic solar cells. In particular, self assembly of conjugated polymeric blocks (with appropriate electronic properties) will provide periodic interfaces of electron donor and electron acceptor materials in the light absorbing active layer of solar cells. This will ensure timely disassociation of bound electron and hole (created on photo-excitation), necessary to produce photocurrent efficiently. Confining fully conjugated rod-rod diblock copolymers within nanofibers will have two benefits. First, it will provide the opportunity to develop a new class of materials, namely, wearable fabrics of organic semiconductors. Secondly, the strong extensional deformation and fast solvent evaporation during electrospinning combined with the physical cylindrical confinement in nanofibers will provide access to novel self assembled structures that may not be possible in equilibrium systems or films.

这项探索性研究的早期概念赠款（急切）提供了资金，以研究完全共轭杆杆二嵌段共聚物的纳米纤维中的受限自组装。纳米纤维将通过称为静电纺丝的工艺制造，该过程使用强球来伸长和薄的聚合物溶液射流，从而实现了纤维的形成，该纤维能够形成近纳米级直径（50-500 nm）。杆杆杆块共聚物将杆状聚合物（长度为1-10 nm）的液晶级排序与螺旋挡板块共聚物（长度为10-100 nm的长度为10-100 nm）的液晶有序结合在一起。将研究溶剂蒸发速率和伸展变形（在静电纺丝期间）对两个长度尺度上自组装结构的影响。纳米纤维中的组件将使用透射电子显微镜以及小角度X射线散射来表征。将作为参考进行有关溶液铸造膜中自组装的类似研究。如果成功，这项工作将为高效有机太阳能电池的设计提供新颖的活性材料。特别是，共轭聚合物块的自组装（具有适当的电子性能）将在吸收太阳能电池的活性层中的电子供体和电子受体材料的周期性界面。这将确保及时分离结合的电子和孔（在光启示上创建），这是有效产生光电流所必需的。限制纳米纤维内完全共轭的杆杆二嵌段共聚物将有两个好处。首先，它将提供开发新型材料的机会，即有机半导体的可穿戴织物。 其次，静电纺丝期间的强伸展变形和快速溶剂蒸发与纳米纤维中的物理圆柱限制相结合，将提供对新型自组装结构的访问，这些结构在平衡系统或膜中可能是不可能的。