CAREER: Electric Field Processing of Polyelectrolyte Complex

职业：聚电解质复合物的电场处理

• 批准号: 1425187
• 负责人: Nicole Zacharia
• 金额: $ 32.92万
• 依托单位: University of Akron
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-01-01 至 2019-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1425187&HistoricalAwards=false
• 关键词: CAREER; Electric; Field; Processing; Polyelectrolyte

TECHNICAL SUMMARY: The work to be conducted under this award is to examine phase behavior of solutions of synthetic polyelectrolyte complexes and to then use an electric field to manipulate these complexes in solution with the goal of depositing them as solids onto substrates. Synthetic polyelectrolytes, both strong and weak, that are typically used in layer-by-layer (LbL) assembly of polyelectrolyte multilayers (such as polyacrylic acid, sulfonated polystyrene, polyallylamine hydrochloride, and polyethylene imine) will be examined. The first part of the work will be to determine phase diagrams for the complexes of different pairs of polyelectrolytes as a function of pH, solution ionic strength, molecular weight, and concentration. The thermodynamic behavior of these complexes is generally masked by kinetic considerations, and unraveling these components will be one goal. The next phase of the work will be to look at adsorption of complexes of different stoichiometries onto charged surfaces. The third phase of the work will be to compare this equilibrium adsorption to deposition onto charged surfaces under the influence of an electric field. Factors including ionic strength, dielectric constant of the solvent, and addition of other components such as metal nanoparticles will be examined. This process will eventually be generalized to look at the electrophoretic deposition of other types of soft matter such as micelles or hollow polyelectrolyte capsules. The last phase of the work is to examine the solid materials created by this process. It is hypothesized that different stoichiometries and properties can be achieved through electric field manipulation as compared to equilibrium adsorption onto a surface.NON-TECHNICAL SUMMARY: Polyelectrolytes (PEs) can be compared very long molecular salts, i.e. long-chain molecules made up of a sequence of either positive or negative charges. They tend to be water-soluble and are often used in pharmaceutical, cosmetic, or food formulations. Biological materials such as proteins and DNA are examples of polyelectrolytes. PEs can be processed into thin coatings with a range of very useful properties by a technique of sequential adsorption steps. These coatings have possible applications in alternative energy devices, biomedical devices, energy saving coatings for windows, and any number of other possibilities. One major barrier to their commercialization is the long time required to make these coatings. The work proposed here is to look at electric fields as a tool to enhance the deposition times for coatings made of polyelectrolytes. This potential has the impact to make these materials commercially viable. This work will help to train PhD students as well as undergraduate students, to engage them in science. Outreach will be done with community college students who are considering transferring into four-year programs. Special attention will be paid to the mentoring of undergraduate and graduate students from under-represented groups, especially female students and those students who are the first in their family to attend college. The PI already has a strong record of working with students from these groups.

技术概要：在该奖项下进行的工作是检查合成的双金属络合物溶液的相行为，然后使用电场在溶液中操纵这些络合物，目的是将它们作为固体沉积到基底上。合成的聚电解质，强和弱，通常用于在逐层（LBL）组装的多层膜（如聚丙烯酸，磺化聚苯乙烯，聚烯丙基胺盐酸盐，聚乙烯亚胺）将被检查。工作的第一部分将是确定作为pH值，溶液离子强度，分子量和浓度的函数的不同对的聚电解质的复合物的相图。这些复合物的热力学行为通常被动力学考虑所掩盖，解开这些组分将是一个目标。下一阶段的工作将着眼于不同化学计量的络合物在带电表面上的吸附。第三阶段的工作将是比较这种平衡吸附到带电表面上的电场的影响下的沉积。将检查包括离子强度、溶剂的介电常数和添加其他组分（如金属纳米颗粒）在内的因素。这一过程最终将被推广到其他类型的软物质，如胶束或中空胶囊的电泳沉积。工作的最后一个阶段是检查这个过程中产生的固体材料。据推测，与平衡吸附到表面上相比，通过电场操纵可以实现不同的化学计量和性质。非技术性概述：聚电解质（PE）可以与非常长的分子盐进行比较，即由一系列正电荷或负电荷组成的长链分子。它们往往是水溶性的，通常用于药物，化妆品或食品配方中。生物材料如蛋白质和DNA是聚电解质的例子。通过连续吸附步骤的技术，可以将PE加工成具有一系列非常有用的特性的薄涂层。 这些涂料可能应用于替代能源设备、生物医学设备、窗户节能涂料以及任何数量的其他可能性。其商业化的一个主要障碍是制造这些涂层所需的长时间。这里提出的工作是看电场作为一种工具，以提高聚电解质制成的涂层的沉积时间。这种潜力具有使这些材料在商业上可行的影响。这项工作将有助于培养博士生以及本科生，让他们从事科学。外联将与社区学院的学生谁正在考虑转入四年制课程。将特别关注对来自代表性不足群体的本科生和研究生的辅导，特别是女生和家中第一个上大学的学生。PI在与这些团体的学生合作方面已经有了很好的记录。