Stimuli-Responsive Shape-Changing Molecular Brushes

刺激响应变形分子刷

• 批准号: 1607076
• 负责人: Bin Zhao
• 金额: $ 49万
• 依托单位: University of Tennessee Knoxville
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1607076&HistoricalAwards=false
• 关键词: Stimuli; Responsive; Shape; Changing; Molecular

PART 1: NON-TECHNICAL SUMMARYMolecular brushes are a class of very long, chain-like molecules consisting of a polymer backbone with densely attached side molecules, so the whole molecular assembly looks like a brush. Their dimensions and shapes are determined by the backbone and side-chain lengths and the interactions of side chains with themselves and their environment. These giant molecules exhibit intriguing properties and are found in the human body performing a wide variety of functions, including joint lubrication, lung clearance, and cell signaling. This project will design, synthesize, develop, and study in detail molecular brushes that can change their sizes and shapes in water in response to environmental variations and stimuli. They will be designed to emulate the behavior of a natural protein in our bodies called the "von Willebrand factor", which causes our blood to clot at the site of an injury, thus stopping the bleeding. The synthetic strategies, properties, and fundamental understanding of such macromolecules will have potential impact to many technologies, including material surface modification, lubrication, medication delivery, etc., thus benefiting society. The research program will also have societal impact via human-resource development. It provides a platform to train next-generation scientists (postdoctoral researchers, graduate and undergraduate students). Outreach activities will be organized in collaboration with local high school teachers, aimed at stimulating the interest of high school students toward STEM fields. PART 2: TECHNICAL SUMMARYThis project is aimed at synthesizing and studying molecular brushes that can exhibit controllable changes in size and shape upon application of external stimuli. Its behavior is inspired by the von Willebrand factor, which enables blood clotting in response to an injury by unraveling from a non-sticky soluble globular shape to an extended nano-object exposing a large number of binding sites to form a clot at the site of an injury. Specifically, the research program will develop general strategies to prepare responsive molecular brushes using state-of-the-art polymer synthesis techniques, investigate stimuli-triggered changes in molecular dimension, conformation, and shape in aqueous solution, and elucidate the effects of various molecular parameters on stimuli-responsive properties. A series of molecular brushes with various molecular architectures, chemical compositions, grafting densities, and molecular weights will be prepared, and their stimuli-responsive behavior in water will be characterized by a broad range of techniques, including dynamic light scattering (DLS), atomic force microscopy (AFM), and transmission electron microscopy (TEM). DLS can conveniently provide in-situ information on molecular dimensions under different conditions; AFM and TEM allow for directly visualizing the brush molecules. The control of interactions of these giant molecules with other macromolecules and solid materials will be demonstrated via external stimuli. The knowledge gained from this study will be used to guide the design and synthesis of functional molecular brushes.

第 1 部分：非技术概要分子刷是一类非常长的链状分子，由聚合物主链和密集连接的侧分子组成，因此整个分子组装体看起来像刷子。 它们的尺寸和形状由主链和侧链长度以及侧链与其自身及其环境的相互作用决定。这些巨型分子表现出有趣的特性，在人体中具有多种功能，包括关节润滑、肺间隙和细胞信号传导。该项目将详细设计、合成、开发和研究分子刷，这些分子刷可以根据环境变化和刺激改变其在水中的大小和形状。 它们将被设计来模仿我们体内一种称为“冯维勒布兰德因子”的天然蛋白质的行为，这种蛋白质会导致我们的血液在受伤部位凝结，从而止血。 此类大分子的合成策略、性质和基本认识将对许多技术产生潜在影响，包括材料表面改性、润滑、药物输送等，从而造福社会。该研究计划还将通过人力资源开发产生社会影响。它提供了一个培养下一代科学家（博士后研究人员、研究生和本科生）的平台。将与当地高中教师合作举办外展活动，旨在激发高中生对 STEM 领域的兴趣。 第 2 部分：技术摘要该项目旨在合成和研究分子刷，这种分子刷可以在施加外部刺激时表现出尺寸和形状的可控变化。其行为受到冯·维勒布兰德因子的启发，该因子通过从非粘性可溶性球状结构解开成扩展的纳米物体，暴露大量结合位点，在损伤部位形成凝块，从而使血液在受伤时凝结。受伤。 具体来说，该研究计划将开发一般策略，使用最先进的聚合物合成技术制备响应性分子刷，研究水溶液中分子尺寸、构象和形状的刺激触发变化，并阐明各种分子的影响刺激响应特性的参数。将制备一系列具有不同分子结构、化学成分、接枝密度和分子量的分子刷，并通过多种技术来表征它们在水中的刺激响应行为，包括动态光散射（DLS）、原子力显微镜（AFM）和透射电子显微镜（TEM）。 DLS可以方便地提供不同条件下分子尺寸的原位信息； AFM 和 TEM 可以直接观察刷子分子。这些巨型分子与其他大分子和固体材料相互作用的控制将通过外部刺激来证明。 从这项研究中获得的知识将用于指导功能性分子刷的设计和合成。

项目成果

Worm-to-Sphere Shape Transition of Thermoresponsive Linear Molecular Bottlebrushes in Moderately Concentrated Aqueous Solution

中等浓度水溶液中热响应线性分子洗瓶刷的蠕虫到球体的形状转变

• DOI: 10.1021/acs.jpcb.8b04767
• 发表时间: 2018-07
• 期刊: The Journal of Physical Chemistry B
• 作者: Henn, Daniel M.;Holmes, Jessica A.;Kent, Ethan W.;Zhao, Bin
• 通讯作者: Zhao, Bin

Effect of Buffer Anions on Pearl-Necklace Morphology of Tertiary Amine-Containing Binary Heterografted Linear Molecular Bottlebrushes in Acidic Aqueous Buffers

缓冲液阴离子对酸性水缓冲液中含叔胺二元异质接枝线性分子瓶刷珍珠项链形貌的影响

• DOI: 10.1021/acs.langmuir.0c02435
• 发表时间: 2020-11
• 期刊: Langmuir
• 影响因子: 3.9
• 作者: Kent, Ethan W.;Lewoczko, Evan M.;Zhao, Bin
• 通讯作者: Zhao, Bin

Shape-Changing Bottlebrush Polymers

变形洗瓶刷聚合物

• DOI: 10.1021/acs.jpcb.1c01819
• 发表时间: 2021-05
• 期刊: The Journal of Physical Chemistry B
• 作者: Zhao; Bin
• 通讯作者: Bin

pH- and chaotropic anion-induced conformational changes of tertiary amine-containing binary heterografted star molecular bottlebrushes in aqueous solution

pH 和离液阴离子诱导的含叔胺二元异质接枝星型分子瓶刷在水溶液中的构象变化

• DOI: 10.1039/d0py01466d
• 发表时间: 2024-09-13
• 期刊: Polymer Chemistry
• 影响因子: 4.6
• 作者: Ethan W. Kent;Evan M. Lewoczko;Bin Zhao
• 通讯作者: Bin Zhao

Effects of N -Substituents on the Solution Behavior of Poly(sulfobetaine methacrylate)s in Water: Upper and Lower Critical Solution Temperature Transitions

N-取代基对聚磺基甜菜碱甲基丙烯酸酯在水中溶液行为的影响：上下临界溶液温度转变

• DOI: 10.1021/acsapm.0c01191
• 发表时间: 2021-02
• 期刊: ACS Applied Polymer Materials
• 影响因子: 5
• 作者: Lewoczko, Evan M.;Wang, Ning;Lundberg, Claire E.;Kelly, Michael T.;Kent, Ethan W.;Wu, Tao;Chen, Ming;Wang, Jian;Zhao, Bin
• 通讯作者: Zhao, Bin