Understanding Architecture Hierarchy of Polymer Networks to Control Mechanical Responses

在材料研究部聚合物项目的支持下，伯明翰大学（UAB）的研究团队正在开发具有微调结构和精确控制物理性能的聚合物网络，例如沿着水凝胶溶胀和表面形态的机械行为。材料结构对于它们在传感、药物输送和组织工程中的应用至关重要。 然而，具有复杂分级结构的纳米薄膜水凝胶的制备还有待探索。拟议的研究的目标将是了解薄纳米结构水凝胶的结构层次的影响，以控制水凝胶的机械响应。这个项目将带来新的见解内部网络安排和刚性之间的相互作用作为一个新颖和有趣的研究领域。这些知识将导致开发出更多样化和更坚固的聚合物结构，能够根据需求进行弹性变化，这将大大拓宽我们控制生物反应和模拟生物组织的能力。该项目的教育和推广活动将促进妇女和代表性不足的群体参与本科生和研究生的科学研究。该项目还旨在通过伯明翰科学中心的知识传播，提高公众对聚合物网络的认识和对科学的参与。教育和推广工作将提高UAB生物医学研究界对新聚合物基材料需求的认识，并有助于提高美国在该领域的经济竞争力。本项目将探讨薄水凝胶涂层的内部结构和结构层次调节刚度。涂层将作为多层水凝胶使用聚合物在表面的顺序吸附而获得。将追求以下目标：（a）理解非牺牲聚合物的分子量对多层水凝胶分层和机械性能的影响;（B）研究多层交联对水凝胶分层和机械性能的影响;和（c）理解聚合物链疏水性对多层水凝胶分层的作用。所提出的研究的主要基本意义将是在获得新的见解纳米结构的多层网络和它们的刺激响应和机械性能之间的结构-性能关系。这项研究将影响一种新型的聚合物水凝胶与建筑层次调节刚度的发展，并将提供这些材料的物理化学性质的基本了解。所提出的研究的具体影响将是（i）开发具有受控内部结构层次的新型共聚物和新型平面水凝胶，（ii）产生关于结构层次对分层水凝胶的尺寸变化和机械响应的影响的新知识;和（iii）为开发水凝胶结构作为用于受控药物递送的可自转化材料开辟了新的前景，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。

With the support of the Polymers program in the Division of Materials Research, the University at Alabama-Birmingham (UAB) research team is developing polymeric networks with finely tuned architectures and precisely controlled physical properties, such as mechanical behavior along with hydrogel swelling and surface morphology. Materials architecture would be essential for their applications in sensing, drug delivery, and tissue engineering. However, the preparation of nanothin hydrogels with complex hierarchical structures has yet to be explored. The goal of the proposed study will be to understand the effects of architecture hierarchy in thin nanostructured hydrogels for controlling hydrogel mechanical responses. This project will bring new insights into the interplay between internal network arrangement and rigidity as a novel and intriguing research area. This knowledge will result in the development of more diverse and robust polymeric structures capable of elastic change on demand, which would vastly broaden our capabilities to control biological responses and mimic biological tissues. The educational and outreach activities of this project will enhance science participation of women and underrepresented groups in undergraduate and graduate research. The project will also aim to increase public awareness of polymer networks and engagement with science through knowledge dissemination at the Birmingham Science Center. The education and outreach efforts will provide awareness of UAB biomedical research community toward a need for new polymer-based materials and contribute to the economic competitiveness of the USA in this field. This project will explore the internal architecture- and architecture hierarchy-regulated rigidity of thin hydrogel coatings. The coatings will be obtained as multilayer hydrogels using sequential adsorption of polymers at surfaces. The following aims will be pursued: (a) understanding the effect of molecular weight of a non-sacrificial polymer on multilayer hydrogel stratification and mechanical properties; (b) investigating the effect of multilayer crosslinking on hydrogel stratification and mechanical properties; and (c) understanding the role of polymer chain hydrophobicity on multilayer hydrogel stratification. The main fundamental significance of the proposed study will be in obtaining new insights into the structure-property relationships between nanostructured multilayer networks and their stimuli-responsive and mechanical properties. This research will impact the development of a new type of polymer hydrogel with architecture hierarchy-regulated rigidity and will provide a fundamental understanding of the physicochemical properties of these materials. The specific impact of the proposed study will be in (i) developing novel copolymers and new types of planar hydrogels with controlled internal architecture hierarchy, (ii) generating new knowledge on the effect of architecture hierarchy on dimensional changes and mechanical responses of the stratified hydrogels; and (iii) opening new prospects for developing hydrogel structures as self-transformable materials for controlled drug delivery, and in rigidity-directed transport in microfluidic environments.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.