Collaborative Research: Role of Polymer Sequence on Penetrant Transport in Charged Brushes

合作研究：聚合物序列对带电刷中渗透剂传输的作用

• 批准号: 2113769
• 负责人: Jacinta Conrad
• 金额: $ 28.05万
• 依托单位: University of Houston
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2113769&HistoricalAwards=false
• 关键词: Collaborative; Research; Role; Polymer; Sequence

Molecular-scale brushes, created by grafting polymers to surfaces, can be used to control the properties of the surface, including its charge, wettability, permeability, and response to environmental conditions such as salt concentration. In principle, polymer brush-coated surfaces are potentially transformative technologies for important applications in drug delivery, chemical separation processes, and water purification. Selectively controlling the transport of small molecules and particles into and out of the brush is necessary for these applications, but the ability to do so remains a persistent challenge because it is difficult to tune the structure of the brush. This research project will develop a route to control brush conformation and its response to environmental conditions by engineering the sequence of monomers that compose the polymer brush. The team will relate the structure of the engineered brushes to how small molecules and particles move through them under static and flow conditions. This research will address a critical knowledge gap by providing understanding of how the sequence of charged polymers affect the transport of penetrants, leading to improved membrane coatings for water and biologic drug purification. The project team will disseminate these results to scientists and engineers in Houston’s petrochemical, biomedical, and materials industries through local meetings, including the Texas Soft Matter Meeting. In parallel, they will develop educational outreach videos on water purification in multiple languages spoken in the Houston metro area, and present hands-on demonstrations for the general public at the Houston Energy Festival.The objective of this project is to develop fundamental understanding of the influence of polymer sequence on transport within charged polymer brushes. Team members from two nearby universities in Houston will integrate complementary expertise in sequence-controlled polymer synthesis (Marciel – Rice University), neutron scattering applied to brushes (Conrad – University of Houston), and state-of-the-art microscopy techniques (Marciel and Conrad) to address three specific aims: (1) determine the role of polymer sequence on brush properties, (2) identify mechanisms that dictate coupling between penetrant and charged polymer brush dynamics, and (3) understand the effects of flow on out-of-equilibrium penetrant transport in charged polymer brushes. Protein engineering methodologies will be used to synthesize sequence-controlled charged polymers with isotopic labelling for grazing-incidence small angle neutron scattering (GI-SANS) and neutron reflectivity (NR) experiments to measure brush conformation and height in equilibrium and out-of-equilibrium conditions. Penetrant transport coefficients will be measured using confocal and total internal reflection fluorescence correlation spectroscopy (TIR-FCS), exploiting vertical sensitivity to distinguish transport inside and outside brushes and tested against theories for diffusion and dispersion within polymer matrices and in porous media. Together, these studies will provide new insight into the role of charge spacing and fraction on the diffusive and flow-driven transport of penetrants in charged brushes, which will pave the way for the design of advanced responsive surfaces.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

通过将聚合物接枝到表面而产生的分子尺度刷子可用于控制表面的特性，包括其电荷、润湿性、渗透性以及对盐浓度等环境条件的响应原则上，聚合物刷子涂覆的表面是。对于药物输送、化学分离过程和水净化等重要应用来说，有必要采用潜在的变革性技术来选择性地控制小分子和颗粒进出刷子的传输，但这样做的能力仍然是一个持续的挑战，因为。很难该研究项目将开发一种通过设计构成聚合物刷的单体序列来控制刷子构象及其对环境条件的响应的方法，该团队将设计的刷子的结构与小分子的大小联系起来。该研究将通过了解带电聚合物的序列如何影响渗透剂的传输来解决关键的知识空白，从而改进用于水和生物药物纯化的膜涂层。将会传播通过当地会议（包括德克萨斯州软物质会议）向休斯顿石化、生物医学和材料行业的科学家和工程师展示这些结果，同时，他们还将以休斯顿都会区的多种语言制作有关水净化的教育宣传视频。并在休斯顿能源节上向公众展示实践演示。该项目的目标是加深对聚合物序列对带电聚合物刷内传输的影响的基本了解，来自休斯顿附近两所大学的团队成员将整合互补的内容。序列控制聚合物合成方面的专业知识（Marciel – 莱斯大学）、应用于刷子的中子散射（康拉德 – 休斯顿大学）以及最先进的显微镜技术（Marciel 和 Conrad），以实现三个具体目标：(1) 确定聚合物序列在刷子上的作用性质，（2）确定决定渗透剂和带电聚合物刷动力学之间耦合的机制，以及（3）了解流动对带电聚合物刷中不平衡渗透剂运输的影响将用于合成蛋白质工程方法。将测量带有同位素标记的序列控制带电聚合物，用于掠入射小角中子散射（GI-SANS）和中子反射率（NR）实验，以测量平衡和非平衡条件下的刷子构象和高度。使用共焦和全内反射荧光相关光谱 (TIR-FCS)，利用垂直灵敏度来区分刷内部和外部的传输，并根据聚合物内的扩散和分散理论进行测试总之，这些研究将为电荷间距和分数对带电刷中渗透剂的扩散和流动驱动传输的作用提供新的见解，这将为先进响应表面的设计铺平道路。授予 NSF 的法定使命，并通过评估反映使用基金会的智力优点和更广泛的影响审查标准，被认为值得支持。

项目成果

Electrostatic Repulsion Slows Relaxations of Polyelectrolytes in Semidilute Solutions

静电斥力减缓半稀溶液中聚电解质的弛豫

• DOI: 10.1021/acsmacrolett.2c00213
• 发表时间: 2022-07
• 期刊: ACS Macro Letters
• 影响因子: 7.015
• 作者: Slim, Ali H.;Shi, Winnie H.;Safi Samghabadi, Farshad;Faraone, Antonio;Marciel, Amanda B.;Poling;Conrad, Jacinta C.
• 通讯作者: Conrad, Jacinta C.

Imaging Heterogeneous 3D Dynamics of Individual Solutes in a Polyelectrolyte Brush

聚电解质刷中单个溶质的异质 3D 动力学成像

• 发表时间: 2023-06
• 期刊: Langmuir
• 影响因子: 3.9
• 作者: Fan, D;Ramezani Bajgiran, S.;Safi Samghabadi, F.;Dutta, C.;Gillett, E.;Rossky, P. J.;Conrad, J. C.;Marciel, A. B.;Landes, C. F.
• 通讯作者: Landes, C. F.

pH response of sequence-controlled polyampholyte brushes

序列控制聚两性电解质刷的 pH 响应

• DOI: 10.1039/d3sm00447c
• 发表时间: 2023-06
• 期刊: Soft Matter
• 影响因子: 3.4
• 作者: Yuan, Xin;Hatch, Harold W.;Conrad, Jacinta C.;Marciel, Amanda B.;Palmer, Jeremy C.
• 通讯作者: Palmer, Jeremy C.

Shaping the Structure and Response of Surface-Grafted Polymer Brushes via the Molecular Weight Distribution

通过分子量分布塑造表面接枝聚合物刷的结构和响应

• 发表时间: 2023-02
• 期刊: JACS Au
• 影响因子: 8
• 作者: Conrad, J. C.;Robertson, M. L.
• 通讯作者: Robertson, M. L.

Dynamics of Filamentous Viruses in Polyelectrolyte Solutions

丝状病毒在聚电解质溶液中的动力学

• DOI: 10.1021/acs.macromol.2c01641
• 发表时间: 2022-12
• 期刊: Macromolecules
• 影响因子: 5.5
• 作者: Safi Samghabadi, Farshad;Slim, Ali H.;Smith, Maxwell W.;Chabi, Maede;Conrad, Jacinta C.
• 通讯作者: Conrad, Jacinta C.