Engineering a localized pH switch at the solid-liquid interface

该奖项的研究目标是开发一类新的表面改性技术，该技术使用可编程铁电衬底来控制固/液界面处的局部氢离子浓度（pH值）。 在这项工作中利用的关键概念是，极化的铁电薄膜产生强烈的电场，可以大大改变附近的铁电体表面的反离子浓度。通过控制铁电膜的局部极化状态，将有可能在非常大的操作范围（即，从低至pH = 0到高至pH = 14）上精确地调节局部pH。该研究方法将采用表征工具的组合，包括AFM，pH染料和自组装单分子膜，以研究极化铁电薄膜上方的局部pH。 还将开发计算技术来比较和解释实验结果。 如果成功的话，本研究的结果将提供一个机会，通过使用pH敏感的Fmoc保护性阻断化学的分步重复合成来创建用于合成多肽微阵列的紧凑装置。 此外，这项研究可用于调节表面润湿性能，在微流体系统中提供额外的控制程度。 由于这项工作的高度跨学科性质，研究生和本科生将广泛接触电磁学，化学，生物学和计算机科学领域。历史上的黑人学院和大学（HBCU？历史上的少数民族大学（HMU？s），将包括在这项工作的两个夏季月。此外，杜克大学的本科生将通过杜克大学普拉特研究员计划参与这项研究。

The research objective of this award is to develop a new class of surface modification techniques that use programmable ferroelectric substrates to control the local hydrogen ion concentration (pH) at the solid/liquid interface. The key concept exploited in this work is that polarized ferroelectric films produce intense electric fields which can substantially alter the counterion concentration near the surface of the ferroelectric. By controlling the local polarization state of the ferroelectric film, it will be possible to precisely tune the local pH over a very large operating range (i.e. from as low as pH=0 to as high as pH=14). The research approach will employ a combination of characterization tools, including AFM, pH dyes, and self-assembled monolayers to study the local pH above polarized ferroelectric films. Computational techniques will also be developed to compare and interpret the experimental results. If successful, the results of this research will provide an opportunity to create a compact device for synthesizing polypeptide micro-arrays via step and repeat synthesis using pH sensitive Fmoc protective blocking chemistry. Additionally, this research may be used to modulate surface wetting properties, providing an additional degree of control in microfluidic systems. Due to the highly interdisciplinary nature of this work, graduate and undergraduate students will have broad exposure to the fields of electromagnetism, chemistry, biology and computer science. Minority studies from Historically Black College and Universities (HBCU?s) or Historically Minority Universities (HMU?s), will be included in this work for two summer months. In addition, undergraduate students from Duke University will participate in this research through the Duke University Pratt Fellows program.