Reconfigurable Polymer Interfaces for Dynamic Interactions and Differentiation of Soft Colloids

用于软胶体动态相互作用和分化的可重构聚合物界面

• 批准号: 1904365
• 负责人: Sergiy Minko
• 金额: $ 43.5万
• 依托单位: University of Georgia Research Foundation Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1904365&HistoricalAwards=false
• 关键词: Reconfigurable; Polymer; Interfaces; Dynamic; Interactions

PART 1: NON-TECHNICAL SUMMARY Phenomena derived from the exposure of surfaces of polymeric materials to their environment or in contact with other materials are relevant to many practical applications. Dynamically changing polymer interfaces are an important class of materials that adapt their properties upon external stimuli according to a preprogrammed scenario. This project aims for the development and study of specially designed polymer interfaces which, in response to stimuli, could attract and repel microscopic objects such as colloids, liquid droplets, particles, vesicles, viruses, or biological cells. Dynamic switching between repulsion and attraction will be adjusted and used for selection, differentiation, and isolation of the particulates. Such dynamic interfaces could be able to extract and remove traces of particles of toxic and hazardous materials, soil particles, oil droplets, bacteria, and viruses from various media such as drinking water, blood, food, and surfaces of commodity and specialty materials and devices. On the other side, such dynamic interfaces would be able to differentiate and extract valuable particulates if they are very diluted in mixtures with other ingredients, for example sediments containing noble and rare metals, some types of human stem cells and other biological samples, and samples of soils in agricultural fields and in space missions. The major challenge being addressed in the project is to understand the complex dynamic mechanisms of the interaction of functional polymer interfaces with various particulates possessing different properties and then to apply the obtained knowledge for proper design of the reconfigurable dynamic interfaces. This project also provides a mechanism to educate a new generation of professionals capable of creative and transformative thinking. Advanced polymer science research is attracting many talented young men and women of different backgrounds and training levels, including high school, undergraduate, graduate students and postdoctoral scholars, who care and feel responsible for the development of a strong and healthy national economy, clean and sustainable environment, and societal prosperity. This project will serve the purpose of developing their skills and experience.PART 2: TECHNICAL SUMMARYInteractions with polymer interfaces via adsorption-desorption mechanisms are limited by the quasi-irreversible adsorption character of polymers, i.e., approaching the equilibrium is hampered by very slow desorption kinetics due to a high activation free energy of the detachment of all adsorbed segments at once. These properties are revealed as strong and quasi-irreversible adsorption of colloidal particulates, liquid droplets, vesicles, proteins, microbes, etc. on the surface of various materials. Whereas this inherent property of polymeric interfaces is advantageous for adhesive applications, this adhesion hysteresis causes complications for affinity-based discrimination of various particulates in complex mixtures for numerous applications. This project aims to develop a novel mechanism of surface differentiation and selective transport of soft colloids owing to dynamic polymeric surfaces with specially designed functionality, microstructure, and dynamic response. This mechanism will be realized by exploring dynamically oscillating polymer interfaces made of distinctive attractive, adhesive, and repulsive micro-domains of microstructured polymer brushes that undergo temperature-driven phase transitions. The adhesive domains will have covalently bound functional motifs that target complementary motifs on the surface of soft colloids of interest. The 2D-interfaces will be designed with anisotropic patterns of microdomains. The different microdomains will have variable dimensions and surface concentration of the specific motifs. A traveling temperature gradient will be applied to facilitate directed transport of soft colloids. The key challenges of the study consist in developing a fundamental understanding of the dynamic interaction of the microstructured polymer-brush interfaces with the soft colloids having different dimensions, elasticity, and composition of surface functional groups, as well as relaxation times. The attachment-detachment dynamic equilibrium controlled by osmotic pressure of swollen repulsive domains, deformation of soft particles, entropic penalty of stretched adhesive domains, and adhesion energy of complimentary motifs will be analyzed in specially designed experiments using soft lipid or block-copolymer vesicles and compared with results of computer simulations. .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.

第一部分：聚合物材料表面暴露于其环境或与其它材料接触而产生的现象与许多实际应用有关。动态变化的聚合物界面是一类重要的材料，其根据预先编程的方案在外部刺激下适应其性质。该项目旨在开发和研究专门设计的聚合物界面，这些界面可以响应刺激，吸引和排斥微观物体，如胶体，液滴，颗粒，囊泡，病毒或生物细胞。排斥和吸引之间的动态切换将被调整并用于颗粒的选择、区分和隔离。这种动态界面能够从各种介质（例如饮用水、血液、食物以及商品和特种材料和设备的表面）中提取和去除痕量的有毒和有害材料的颗粒、土壤颗粒、油滴、细菌和病毒。另一方面，如果有价值的微粒在与其他成分的混合物中被大大稀释，例如含有贵金属和稀有金属的沉积物、某些类型的人类干细胞和其他生物样品以及农田和空间飞行任务中的土壤样品，这种动态界面将能够区分和提取这些微粒。该项目面临的主要挑战是了解功能聚合物界面与具有不同性质的各种颗粒相互作用的复杂动态机制，然后将所获得的知识应用于可重构动态界面的正确设计。该项目还提供了一种机制，以教育新一代能够进行创造性和变革性思维的专业人员。先进的聚合物科学研究吸引了许多不同背景和培训水平的有才华的年轻男女，包括高中生，本科生，研究生和博士后学者，他们关心并感到有责任发展强大和健康的国民经济，清洁和可持续的环境，以及社会繁荣。该项目将有助于发展他们的技能和经验。第2部分：技术总结通过吸附-脱附机制与聚合物界面的相互作用受到聚合物的准不可逆吸附特性的限制，即，由于所有吸附片段同时分离的高活化自由能，接近平衡受到非常慢的解吸动力学的阻碍。这些性质表现为胶体颗粒、液滴、囊泡、蛋白质、微生物等在各种材料表面上的强且准不可逆的吸附。尽管聚合物界面的这种固有性质对于粘合剂应用是有利的，但是这种粘合滞后导致对于许多应用的复杂混合物中的各种颗粒的基于亲和力的区分的复杂化。该项目旨在开发一种新的表面分化和软胶体的选择性运输机制，由于动态聚合物表面具有专门设计的功能，微观结构和动态响应。这种机制将通过探索动态振荡的聚合物界面来实现，该界面由经历温度驱动相变的微结构聚合物刷的独特吸引性、粘附性和排斥性微域组成。粘附结构域将具有共价结合的功能基序，其靶向感兴趣的软胶体表面上的互补基序。二维界面将被设计为具有微域的各向异性图案。不同的微区将具有可变的尺寸和特定基序的表面浓度。将施加移动温度梯度以促进软胶体的定向输送。该研究的主要挑战在于发展的动态相互作用的微结构的聚合物刷接口与软胶体具有不同的尺寸，弹性和组成的表面官能团，以及弛豫时间的基本理解。在专门设计的实验中，使用软脂质或嵌段共聚物囊泡和计算机模拟的结果相比，膨胀排斥域的渗透压，软颗粒的变形，熵罚拉伸粘合域，和粘附能的互补图案控制的附着-脱离动态平衡进行分析。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Preprogrammed Dynamic Microstructured Polymer Interfaces

• DOI: 10.1002/adfm.201903478
• 发表时间: 2019-08
• 期刊: Advanced Functional Materials
• 影响因子: 19
• 作者: I. Tokarev;S. Minko

All-Nanoparticle Monolayer Broadband Antireflective and Self-Cleaning Transparent Glass Coatings

• DOI: 10.1021/acsami.0c18776
• 发表时间: 2021-02-01
• 期刊: ACS APPLIED MATERIALS & INTERFACES
• 影响因子: 9.5
• 作者: Gruzd, Alexey;Tokarev, Alexander;Minko, Sergiy
• 通讯作者: Minko, Sergiy