Microbial Interactions with Biodegradable Polymer Nanocomposites that Incorporate Carbon Nanotubes

微生物与含有碳纳米管的可生物降解聚合物纳米复合材料的相互作用

• 批准号: 1236493
• 负责人: Howard Fairbrother
• 金额: $ 30万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-11-01 至 2016-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1236493&HistoricalAwards=false
• 关键词: Microbial; Interactions; Biodegradable; Polymer; Nanocomposites

This NSF award by the Environmental Health and Safety of Nanotechnology program supports multidisciplinary work by Professors Howard Fairbrother, Ed Bouwer and Seth Guikema to characterize the effect of microbial interactions with biodegradable polymers that incorporate carbon nanotubes (CNTs). Polymer nanocomposites containing CNTs represent an example of a next generation type of nanomaterial because of the beneficial effects that CNTs have on many polymer properties. However, following consumer use polymer nanocomposites will enter the environment where their ultimate fate and impact will be intimately dependent upon their interactions with microorganisms present in environmental regimes such as landfills, soils or surface waters. To better understand the life cycle of this new class of nanomaterials we plan to develop a systematic understanding of the persistence and fate of biodegradable polymer nanocomposites exposed to different microbial populations, including potential pathways for CNT release. Findings from these experiments will also be used as the basis to develop a risk-based decision making framework that can determine the most appropriate means for disposing of polymer nanocomposites. Such a proactive approach for risk assessment and life cycle analysis is necessary for new types of nanomaterials in the developmental stage. Intellectual Merit: The experimental design is to establish relationships that link important parameters, such as CNT loading, type and surface chemistry with biodegradation and biofilm accumulation rates and biotransformation mechanisms. Through this approach environments will be identified where CNTs could be released as particles from the solid phase composite and where biodegradable polymer nanocomposites could resist biodegradation and persist, in stark contrast to the behavior of the native polymer. The PIs will initially focus on preparing a selected suite of well characterized CNTs and CNT-containing biodegradable polymer nanocomposites where CNT type, surface chemistry, loading and the biodegradable polymer matrix will be varied. Using selected single and mixed culture populations to mimic different environmental regimes, microbial interactions with polymer nanocomposites and CNT particles will be explored by conducting three types of complementary experiments: (1) flow cell studies to evaluate attachment and biofilm accumulation on the surface of the polymer nanocomposites, (2) batch studies to quantify biodegradation and CNT release, and (3) isotopically labeled CNTs to determine the fate of CNT-carbon and potential CNT degradation mechanisms. Broader Impacts - This research will develop a fundamental and holistic scientific understanding of microbial interactions with CNT-containing biodegradable polymer nanocomposites, an emerging class of nanomaterial with enormous commercial potential. This information will also provide a predictive framework for the development of nanocomposites with material properties that have been engineered for positive social and economic consequences without long term industrial liability. The PIs will also provide research opportunities, guidance, and mentoring to female high school juniors through the Women in Science and Engineering program and female undergraduate students from the Notre Dame of Maryland University (a local, primarily teaching, women?s college). Additionally, the PIs and graduate students will give presentations in a pilot program, the City Springs Science Outreach Program, which focuses on enhancing scientific literacy and awareness for minority and underprivileged grade school students (5th grade) through exposure to hands-on science and engineering projects and activities.

该 NSF 奖项由纳米技术环境健康与安全项目颁发，支持 Howard Fairbrother、Ed Bouwer 和 Seth Guikema 教授的多学科工作，以表征微生物与含有碳纳米管 (CNT) 的可生物降解聚合物相互作用的影响。含有碳纳米管的聚合物纳米复合材料代表了下一代纳米材料的一个例子，因为碳纳米管对许多聚合物性能都有有益的影响。然而，消费者使用后，聚合物纳米复合材料将进入环境，其最终命运和影响将密切取决于它们与垃圾填埋场、土壤或地表水等环境体系中存在的微生物的相互作用。为了更好地了解这类新型纳米材料的生命周期，我们计划系统地了解暴露于不同微生物种群的可生物降解聚合物纳米复合材料的持久性和命运，包括碳纳米管释放的潜在途径。这些实验的结果也将用作开发基于风险的决策框架的基础，该框架可以确定处理聚合物纳米复合材料的最合适的方法。对于处于开发阶段的新型纳米材料来说，这种主动的风险评估和生命周期分析方法是必要的。智力优点：实验设计旨在建立将重要参数（例如碳纳米管负载、类型和表面化学）与生物降解、生物膜积累速率和生物转化机制联系起来的关系。通过这种方法，将确定碳纳米管可以作为颗粒从固相复合材料中释放出来的环境，以及可生物降解的聚合物纳米复合材料可以抵抗生物降解并持续存在的环境，这与天然聚合物的行为形成鲜明对比。 PI 最初将专注于制备一系列经过充分表征的 CNT 和含 CNT 的可生物降解聚合物纳米复合材料，其中 CNT 类型、表面化学、负载和可生物降解聚合物基质将有所不同。使用选定的单一和混合培养群体来模拟不同的环境状况，将通过进行三种类型的互补实验来探索微生物与聚合物纳米复合材料和碳纳米管颗粒的相互作用：（1）流动细胞研究，以评估聚合物表面的附着和生物膜积累纳米复合材料，（2）批量研究以量化生物降解和碳纳米管释放，以及（3）同位素标记的碳纳米管以确定碳纳米管-碳的命运和潜在的碳纳米管降解机制。更广泛的影响——这项研究将对微生物与含碳纳米管的可生物降解聚合物纳米复合材料的相互作用形成基本和全面的科学理解，这是一种具有巨大商业潜力的新兴纳米材料。这些信息还将为具有材料特性的纳米复合材料的开发提供预测框架，这些材料特性的设计可以产生积极的社会和经济后果，而不会产生长期的工业责任。 PI 还将通过女性科学与工程项目以及马里兰圣母大学（当地的一所主要教学女子学院）的女本科生为高中三年级女学生提供研究机会、指导和指导。此外，PI 和研究生将在试点项目 City Springs Science Outreach Program 中进行演讲，该项目的重点是通过接触科学和工程实践来提高少数族裔和贫困小学学生（五年级）的科学素养和意识项目和活动。