BRIGE: Engineering Antifouling Ultrafiltration Membranes Using Polycationic Nanofibers

背景：在全球范围内，腹泻仍然是儿童死亡的第二大原因。虽然基于膜的技术可以有效地降低这一死亡率，但与保持膜性能相关的成本使发展中国家无法继续获得安全饮用水。NSF-Brige的这项提案开启了新一代抗菌超滤膜，这种膜将在操作系统中使用更长时间。技术说明：聚砜超滤膜将使用聚阳离子/聚环氧乙烷纳米纤维垫进行表面功能化。纳米纤维层将通过与暴露的阳离子表面电荷接触来灭活广泛的微生物。聚环氧乙烷的含量将使膜表面更亲水，从而更耐微生物附着。对于聚阳离子，我们将研究生物聚合物壳聚糖，以及合成的类似物，聚(二甲基二烯丙基氯化铵)。纳米纤维增强的超滤膜将在功能、生物污染和材料特性方面进行表征。这项研究将提供高孔隙率纳米纤维膜作为超滤膜的薄层与其在操作条件下保持高通量和灭活微生物的能力之间的关键结构-性能关系。这些纳米结构增强的超滤膜通过向当地市政当局和欠发达社区提供安全、高质量的水，有可能在地方、国家和全球范围内影响水质。除了提高净水膜的功能和寿命外，了解材料-生物界面对膜的正常功能具有重要影响，用于广泛的分离，包括饮料澄清、血液过滤/处理、蛋白质净化和金属离子回收。广泛的意义和重要性：通过这项工作，将获得制造以“绿色”抗菌剂为特色的低成本净水膜的新见解。这项技术通过向当地市政当局和欠发达社区提供安全、高质量的水，有可能在地方、国家和全球范围内影响水质。水量和水质的持续下降是一种切实的社会影响，使该项目成为在广泛的人口结构中传播STEM学科的重要作用的强大工具。扩大未被充分代表的群体在工程学中的参与：该项目的一个关键组成部分是在化学工程、材料科学和环境工程的新兴界面上教育和指导不同的劳动力。除了她正在进行的努力外，这项建议还将为聋人或重听本科生以及女性和少数族裔本科生和研究生带来许多新的研究经验。此外，国际和平协会将担任两个新的网上国际讨论小组的主持人。第一个将增加全球获得科学知识的机会，第二个将为服务不足的妇女群体提供一个安全的妇女导师网络，这些妇女生活在可能没有其他妇女榜样的偏远地区。此外，国际和平研究所将担任全球材料网络维持的两个新的网上国际讨论小组的主持人。第一个将是一个专题论坛，以增加全球范围内获得“聚合物”科学知识的机会。第二个是“工程中的妇女讨论小组”，它将为偏远地区的妇女提供指导网络，那里可能没有其他妇女的榜样，这是一个服务不足的妇女群体。这项研究是通过扩大工程招揽中的参与研究启动补助金资助的，这是工程教育和中心司扩大工程参与计划的一部分。

Background:Globally, diarrhea remains the second leading cause of childhood mortality. While membrane-based technologies can effectively diminish this mortality rate, the costs associated with retaining membrane performance prohibits developing countries from maintaining access to safe drinking water. This NSF-BRIGE proposal embarks on a new generation of antimicrobial ultrafiltration membranes that will last longer in operational systems. Technical Description:Polysulfone ultrafiltration membranes will be surface functionalized with polycationic/poly(ethylene oxide) nanofiber mats. The nanofiber layer will inactivate a broad-spectrum of microbes via contact with the exposed cationic surface charges. The poly(ethylene oxide) content will render the membrane surface more hydrophilic, and thus, more resistant to microbial attachment. For the polycation, we will investigate the biopolymer chitosan, as well as a synthetic analogue, poly(dimethyldiallylammonium chloride). Ultrafiltration membranes enhanced with nanofibers will be characterized for functionality, biofouling, and their materials properties.This research will provide critical structure-property relationships between high porosity nanofiber mats applied as a thin-layer on ultrafiltration membranes and their ability to retain high flux and inactivate microbes under operational conditions. These nanostructure-enhanced ultrafiltration membranes hold the potential to impact water quality on a local, national, and global scale by providing safe, high-quality water to local municipals and underdeveloped communities. In addition to improving the functionality and lifetime of membranes for water purification, understanding the materials-biology interface has great implications on the proper functioning of membranes for a broad range of separations, including, beverage clarification, blood filtration/treatment, protein purification, and metal ion recovery.Broader Signficance and Importance:From this work, new insights into the manufacturing of low cost, water purification membranes that feature "green" antimicrobials will be acquired. This technology holds the potential to impact water quality on a local, national, and global scale by providing safe, high-quality water to local municipals and underdeveloped communities. The continuous decline in water quantity and quality is a tangible societal impact that makes this project a powerful vehicle for communicating the vital role of STEM disciplines over a broad demographic.Broadening Participation of Underrepresented Groups in Engineering:A key component of this project is its aim to educate and mentor a diverse workforce at the emerging interface of chemical engineering, materials science, and environmental engineering. In addition to her on-going efforts, this proposal will result in numerous new research experiences for deaf or hard-of hearing undergraduate students, as well as women and minority undergraduate and graduate students. Additionally, the PI will act as the moderator to two new web-based international discussion groups. One will increase access to scientific knowledge globally and the second will provide a safe women-mentorship network to an underserved population of women, those living in remote places where there may not be other women role models. Additionally, the PI will act as the moderator to two new web-based international discussion groups maintained by the Global Materials Network. The first will be a topical forum to increase access to scientific knowledge on "Polymers" globally. The second, will be a "Women in Engineering Discussion Group" that will provide a mentorship network to women in remote locations where there may not be other women role models, an underserved population of women.This research has been funded through the Broadening Participation Research Initiation Grants in Engineering solicitation, which is part of the Broadening Participation in Engineering Program of the Engineering Education and Centers Division.