Formation of Multiscale Biopolymer Particle Structures for Novel Biosorbent Design

用于新型生物吸附剂设计的多尺度生物聚合物颗粒结构的形成

• 批准号: 0756220
• 负责人: Nina Shapley
• 金额: $ 28.28万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-02-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0756220&HistoricalAwards=false
• 关键词: Formation; Multiscale; Biopolymer; Particle; Structures

0756220ShapleyThe goal of this proposal is to enhance understanding of the fundamental mechanisms of particle size separation and the processes that control metal ion species adsorption by biopolymer gel micro and nanoparticles, with the aim of guiding the next generation of biosorbent design. Specifically, the work will examine multiphase flow in complex geometries that serve as models for water purification devices in order to discover the mechanisms driving particle size separation phenomena during flow and subsequent adsorption processes. Utilization of abundant and biocompatible natural biopolymers with outstanding sorbent properties and low energy cross-linking routes offers a unique opportunity for effective heavy metal contaminant removal from industrial wastewater streams, a leading environmental concern. Improved insight into the multiphase transport aspects of water purification is essential for improving the efficacy and speed of water treatment. Intellectual Merit: The novelty of this research derives from the proposed experimental study of heterogeneous particle suspensions in complex geometry flows, and mass transfer at the micro and nanoscale in resulting fixed particle beds formed from such flows. During the filling of a typical fixed bed geometry, the flow field is tightly coupled to the nonuniform spatial distribution of particles. Hence, it is beyond the predictive power of current suspension models to anticipate the resulting flows of bimodal suspensions (two particle sizes). In addition, the particle materials, specifically biopolymer gels, are known to have strong complexation and electrostatic interactions with metal ions in solution, but a combined multiscale structure including biopolymer nanoparticles has not been considered. The powerful experimental technique of nuclear magnetic resonance imaging (NMRI) will be used to gather detailed information on several features of particle and species transport. Experimental results will also be compared with state of the art calculations based on continuum modeling of monomodal suspension flows. The specific aims of this research program include: (1) Synthesizing biopolymer microbeads coated with complementary biopolymer nanoparticles and characterizing equilibrium heavy metal ion uptake. (2) Understanding mechanisms of particle size separation in a bimodal suspension flowing through model filtration bed geometries. (3) Quantifying the kinetics of metal ion adsorption in flow through a fixed bed of biopolymer micro-nanoparticle structures. Broader Impact Technology: The fundamental research results can be implemented as long-term practical guidelines for the utilization of complementary biopolymer micro and nanoparticle structures in the next generation of wastewater purification units, in order to improve purification efficiency and employ naturally abundant and environmentally benign materials. Educational Impact: Education and outreach activities will focus on incorporating concepts and results from the research into hands-on, active laboratory experiences for students at multiple educational levels. Hands-on laboratory experiences involving fluid mechanics and rheology will energize programs ranging from an academic enrichment program for disadvantaged high school students to a graduate laboratory course helping to prepare students for doctoral research. Intensive research training in the P.I.?s laboratory, for high school, undergraduate, and graduate students, is also a key component of the educational activities. This unified research and education project will enhance the understanding of multiphase transport issues that are crucial for achieving efficient removal of toxic metal contaminants from water while simultaneously it will engage and train the next generation of scientists in the study of fluid flows and material properties.

0756220 Shapley该提案的目的是加强对粒度分离的基本机制以及控制生物聚合物凝胶微米和纳米颗粒吸附金属离子的过程的理解，目的是指导下一代生物吸附剂的设计。具体来说，这项工作将检查多相流在复杂的几何形状，作为水净化设备的模型，以发现在流动和随后的吸附过程中驱动颗粒尺寸分离现象的机制。利用具有出色吸附性能和低能量交联途径的丰富且生物相容的天然生物聚合物为从工业废水流中有效去除重金属污染物提供了独特的机会，这是一个主要的环境问题。对水净化的多相输送方面的深入了解对于提高水处理的效率和速度至关重要。智力优势：这项研究的新奇来自于复杂几何流动中的非均匀颗粒悬浮液的实验研究，以及由此产生的固定颗粒床从这种流动中形成的微米和纳米级的传质。在典型的固定床几何形状的填充期间，流场与颗粒的不均匀空间分布紧密耦合。因此，这是超出了目前的悬浮液模型的预测能力，以预测双峰悬浮液（两个颗粒尺寸）的所得流量。此外，已知颗粒材料，特别是生物聚合物凝胶，与溶液中的金属离子具有强络合和静电相互作用，但尚未考虑包括生物聚合物纳米颗粒的组合多尺度结构。核磁共振成像（NMRI）的强大的实验技术将被用来收集粒子和物种传输的几个功能的详细信息。实验结果也将进行比较与最先进的计算基础上的连续建模的单峰悬浮液流。本研究的具体目标包括：（1）合成包覆有互补生物聚合物纳米颗粒的生物聚合物微球并表征平衡重金属离子吸收。(2)了解流经模型过滤床几何形状的双峰悬浮液中的粒度分离机理。(3)通过生物聚合物微-纳米颗粒结构的固定床流动中金属离子吸附的动力学定量。更广泛的影响技术：基础研究结果可以作为下一代废水净化装置中利用互补生物聚合物微米和纳米颗粒结构的长期实用指南，以提高净化效率并采用天然丰富和环境友好的材料。教育影响：教育和推广活动将侧重于将研究的概念和结果纳入实践，为不同教育水平的学生提供积极的实验室体验。涉及流体力学和流变学的动手实验室经验将为从弱势高中学生的学术充实计划到帮助学生为博士研究做好准备的研究生实验室课程的课程提供动力。在私家侦探学校接受强化研究训练？实验室，为高中，本科和研究生，也是教育活动的一个重要组成部分。这个统一的研究和教育项目将提高对多相运输问题的理解，这些问题对于实现有效去除水中有毒金属污染物至关重要，同时它将参与并培训下一代科学家研究流体流动和材料特性。