EAGER/Collaborative Research: Experimental Verification of Piezoelectric Augmentation of Strength and Toughness in Polymer Fiber Bundles

有了这个早期概念探索性研究资助（EAGER）的可行性，预期增强压电聚合物纳米纤维束的机械性能将进行探索。压电材料是响应于所施加的电场而产生机械应力（或反之亦然）的响应性材料。该概念的前提是静电相互作用可以增强纱线中压电纤维之间的负载传递，从而潜在地增加纱线的强度和韧性。这一发现可能会影响航空航天和汽车行业的应用，其中纤维增强复合材料因其高强度和轻重量的特点而被使用。这项研究工作将作为一个平台，以培养未来的劳动力为干领域的重点是纳米技术和材料工程。 本研究的目的是通过实验证明变形引起的压电电荷之间的内部长程静电相互作用的大小，以提高纤维合成纱线的机械性能。计划的方法是基于这样的前提下，压电感应电荷之间的静电相互作用的分层结构可以大大提高纱线的纤维之间的负载转移。压电材料力学性能的提高具有潜在的重要意义，并可能通过压电行为的系统工程来影响高性能结构材料的设计。本研究的灵感来自骨的韧性机制和骨的显着的机械性能中的胶原纤维的压电效应的潜在作用。因此，在合成材料中压电增强机械性能的演示可以提供对天然材料力学的新见解。为了实现这一目标，聚合物（聚偏氟乙烯）压电薄膜和纱线将通过静电纺丝工艺制造，并通过机电处理极化。纳米纤维的压电性能和纱线的机械性能将被测量为极化条件的函数。

With this EArly-concept Grant for Exploratory Research (EAGER) the feasibility of an anticipated enhancement of mechanical properties for piezoelectric polymeric bundles of nanofibers will be explored. Piezoelectric materials are responsive materials that generate mechanical stress in response to an applied electric field (or vice versa). The premise for the concept is that electrostatic interactions can enhance load transfer between piezoelectric fibers in a yarn, thereby potentially increasing the strength and toughness of the yarn. This finding could impact applications in aerospace and automotive industries where fiber-reinforced composites are used for their high strength and light weight features. This research effort will serve as a platform to train the future workforce for STEM fields with focus on nanotechnology and materials engineering. The objective of this research is to experimentally demonstrate the magnitude of internal long-range electrostatic interactions between deformation-induced piezoelectric charges toward enhancing the mechanical properties of fibrous synthetic yarns. The planned approach is based on the premise that the electrostatic interactions between piezoelectrically-induced charges in hierarchical structures can considerably enhance load-transfer between fibers of the yarn. The piezoelectric enhancement of mechanical properties is potentially significant, and may impact the design of high performance structural materials through systematic engineering of piezoelectric behavior. This research is inspired by toughness mechanisms in bone and potential role of piezoelectric effect of collagen fibrils in bone's remarkable mechanical properties. As such, demonstration of piezoelectric augmentation of mechanical properties in a synthetic material may provide new insight into mechanics of natural materials. Toward the goal, polymeric (polyvinylidene fluoride) piezoelectric membranes and yarns will be fabricated via electrospinning process and poled via electromechanical treatment. The piezoelectric properties of the nanofibers and the mechanical properties of the yarns will be measured as a function of poling conditions.