Enabling Kinetics and Structural Control of Polymer-Grafted Nanoparticle Superstructures via Solvent Vapor Annealing

非技术概述混合材料使纳米光子学、纳米制造、燃料电池、光伏、纳米薄膜、电池等领域的新应用和新技术成为可能。合理设计的聚合物-纳米颗粒复合材料可以协同聚合物和无机材料的属性，产生单一均质材料无法实现的新的合成和加工可能性和物理性能。在材料研究部固态和材料化学项目的支持下，印第安纳大学叶星晨教授和他的研究小组正在通过自组装开发多功能纳米复合材料。为了通过设计实现纳米复合材料，本研究正在扩展合成和加工工具箱。该项目为研究生和本科生提供纳米材料合成和表征方面的培训。此外，通过与北卡罗来纳A&T州立大学和印第安纳大学的团体学者计划的合作，为代表不足的团体的成员提供夏季研究机会。技术摘要下一代聚合物纳米复合材料的开发需要在纳米颗粒和聚合物基质的合成、有机-无机界面的精确工程以及三维结构控制方面同时取得进展。自组装保证了可伸缩性，提供了分子级的积木设计，并生产出三维材料。通过自组装实现对单个纳米颗粒空间分布的精密控制的关键挑战在于缺乏探测和操纵纳米复合材料形成路径的能力。该项目由材料研究部的固态和材料化学计划支持，通过使用聚合物接枝纳米颗粒(PGNP)构建块来了解和控制使用溶剂蒸气退火的PGNP超结构的动力学路径和相行为，以应对这一挑战。具体地说，该项目将(I)建立用于合成多组分PGNP超结构的溶剂退火法的通用性，(Ii)通过改变溶剂退火参数来展示路径控制和多晶型选择，以及(Iii)将形状各向异性的PGNP组装成紧密堆积和低密度的超结构，并阐明组装路径。这项研究将对决定PGNP组装结果的热力学和动力学因素之间的相互作用提供基本和定量的见解，并将为具有动力学路径控制、前所未有的成分和结构多样性以及可重构性的有序PGNP超结构的预测性合成奠定基础。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

NON-TECHNICAL SUMMARY Hybrid materials are enabling new applications and technologies in nanophotonics, nanofabrication, fuel cells, photovoltaics, nanomembranes, batteries, and more. Rationally designed polymer-nanoparticle composites can synergize the attributes of polymeric and inorganic materials, generating new synthesis and processing possibilities and physical properties that are unattainable with a single homogeneous material. With this project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, Professor Xingchen Ye and his research group at Indiana University are developing multifunctional nanocomposite materials through self-assembly. This research is expanding the synthetic and processing toolbox in order to achieve nanocomposites by design. This project provides training in nanomaterial synthesis and characterization to both graduate and undergraduate students. In addition, summer research opportunities are provided to members of underrepresented groups through partnerships with North Carolina A&T State University and the Groups Scholars Program at Indiana University.TECHNICAL SUMMARY The development of next-generation polymer nanocomposites requires simultaneous advances in the synthesis of nanoparticles and polymer matrices, precise engineering of the organic-inorganic interface, and three-dimensional structural control. Self-assembly promises scalability, provides molecular-level design of building blocks and produces three-dimensional materials. The key challenge in achieving sophisticated control over the spatial distribution of individual nanoparticles through self-assembly lies in the lack of ability to probe and manipulate the pathways of nanocomposite formation. This project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, is addressing this challenge by using polymer-grafted nanoparticle (PGNP) building blocks to understand and control the kinetic pathways and phase behaviors of PGNP superstructures using solvent vapor annealing. Specifically, this project will (i) establish the versatility of solvent annealing for the synthesis of multicomponent PGNP superstructures, (ii) demonstrate pathway control and polymorph selection by changing solvent annealing parameters, and (iii) assemble shape-anisotropic PGNP into close-packed and low-density superstructures and elucidate assembly pathways. This research will provide fundamental and quantitative insight into the interplay between thermodynamic and kinetic factors that dictate PGNP assembly outcome, and will lay the groundwork for predictive synthesis of ordered PGNP superstructures with kinetic pathway control, unprecedented compositional and structural diversity as well as reconfigurability.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.