RUI: Laser-Zone Drawing and Annealing of High Strength Polymer Nanofibers

RUI：高强度聚合物纳米纤维的激光区域拉伸和退火

• 批准号: 2110027
• 负责人: Vince Beachley
• 金额: $ 52.29万
• 依托单位: Rowan University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2110027&HistoricalAwards=false
• 关键词: RUI; Laser; Zone; Drawing; Annealing

This work generates new knowledge associated with laser heating of polymers to engineer and manufacture high strength nanofibers. The scientific knowledge and technological advances generated in the areas of polymer materials science, engineering and manufacturing promote economic growth and benefit society. Polymer nanofibers have widespread applications in a variety of critical industries including energy, transportation, aerospace, healthcare, electronics and sensing. Theoretically, nanofibers are expected to be stronger than larger conventional fibers, but in practice nanofibers are usually much weaker. This discrepancy arises because the manufacturing processes required to engineer ordered internal structures are difficult to apply to tiny, delicate nanofibers. This grant supports the investigation of fundamental scientific relationships associated with laser heating during polymer nanofiber stretching for exceptional control over the internal structure and resulting enhanced strength. Furthermore, the research uses a unique automated track continuous fiber-drawing system that ensures scale up and a clear path to commercialization. The project provides advanced training in materials science, advanced manufacturing and nanotechnology to numerous undergraduate and graduate students and establishes the Path to BS Research Training Program that supports underrepresented, economically disadvantaged students seeking BS degrees in Engineering.Laser zone drawing has demonstrated the potential to produce polymer fibers with high tensile strengths that exceed what is possible using conventional fiber manufacturing methods. However, the fundamental thermodynamic and material processing relationships governing laser zone fiber drawing have not been studied under tightly controlled conditions, especially for polymer nanofibers. This work fills that knowledge gap by using computational models and experimental investigation of polymer fibers subject to laser heating while the mechanical properties are continuously monitored. To process entire fibers, the laser beam is sequentially scanned to rapidly heat each small portion or zone of a fiber to make it pliable so it can be stretched. Macromolecular structure development during laser zone drawing is investigated with known fiber tension and temporal zone temperature. This approach is expected to facilitate remarkable control over the final internal structure of the processed fiber and result in exceptional mechanical strength. The utilization of automated tracks allows for controlled laser zone drawing of the delicate nanofibers. The hypothesis to be tested is that the rapid heating and cooling of nanofibers, due to their high surface area-to-volume ratio, facilitates alignment of polymer chains at elevated temperatures that are locked in place during rapid cooling before chain relaxation can occur, thereby enhancing mechanical behavior.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

这项工作产生了与聚合物激光加热相关的新知识，以设计和制造高强度纳米纤维。高分子材料科学、工程和制造领域产生的科学知识和技术进步促进经济增长，造福社会。聚合物纳米纤维在能源、交通、航空航天、医疗保健、电子和传感等各种关键行业有着广泛的应用。理论上，纳米纤维预计比较大的传统纤维更强，但实际上纳米纤维通常要弱得多。出现这种差异的原因是设计有序内部结构所需的制造工艺很难应用于微小、精致的纳米纤维。该资助支持对聚合物纳米纤维拉伸过程中与激光加热相关的基础科学关系的研究，以实现对内部结构的特殊控制并由此增强强度。此外，该研究使用了独特的自动轨道连续纤维拉丝系统，可确保扩大规模并提供清晰的商业化路径。该项目为众多本科生和研究生提供材料科学、先进制造和纳米技术方面的高级培训，并建立了 BS 研究培训计划，为寻求工程学学士学位的代表性不足、经济困难的学生提供支持。激光区域绘图已证明了产生的潜力具有高拉伸强度的聚合物纤维，超出了使用传统纤维制造方法所能达到的强度。然而，尚未在严格控制的条件下研究控制激光区域光纤拉丝的基本热力学和材料加工关系，特别是对于聚合物纳米纤维。这项工作通过使用计算模型和对受到激光加热的聚合物纤维进行实验研究，同时连续监测机械性能，填补了这一知识空白。为了加工整个光纤，激光束被顺序扫描以快速加热光纤的每个小部分或区域，使其变得柔韧，从而可以拉伸。在已知的光纤张力和颞区温度下研究了激光区域拉伸过程中大分子结构的发展。这种方法有望促进对加工纤维的最终内部结构的显着控制，并产生卓越的机械强度。利用自动轨道可以对精致的纳米纤维进行受控的激光区域绘制。要测试的假设是，纳米纤维的快速加热和冷却，由于其高表面积与体积比，促进了聚合物链在高温下的排列，这些链在链松弛发生之前在快速冷却过程中被锁定在适当的位置，从而该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。