CAREER: Enabling the Design of Versatile Hybrid Materials using Polymerization-Induced Nanostructural Transitions

第1部分：非技术概述实现对比材料性能（如韧性和模量）的同时最大化是单组分材料的一项艰巨挑战。通过分层组织具有不同物理性质的多种成分（生物聚合物和矿物质），生物学能够摆脱单一成分材料的固有局限性。生物材料的静态结构和等级顺序只是故事的一部分；生物学和生命系统通过非平衡过程创造复杂的物质。CAREER提案的目标是研究非平衡化学功能化和自组装方法，以创建多功能杂化聚合物/无机材料。将探索两种聚合物/纳米颗粒材料系统：1)柔性和导电共连续网络；2)具有特殊应变硬化机械性能的纳米结构材料。在材料设计中建立和整合非平衡化学过程将有可能导致新材料在基础设施、交通运输、医疗保健和信息处理方面的应用。该提案的研究目标将通过以下方式整合到教学方法中：1)为宾夕法尼亚州非博士学位授予机构的教授开发聚合物/材料科学模块和实验室，以增加本科课程；2)为所有感兴趣的研究人员创建开放访问视频标准操作程序（VSOP），以学习聚合物合成，样品制备和表征的详细方法。混合聚合物/无机材料领域一直在平衡概念将导致自然界中看到的复杂材料的前提下工作，然而生物学利用非平衡过程来创造生物材料。该提案的总体目标是利用非平衡化学功能化和自组装方法确定设计标准，通过聚合诱导的纳米结构转变来创建多功能杂化聚合物/无机材料。在本研究中，将使用原位聚合物接枝和原位嵌段聚合物合成方法，将聚合物附着在纳米颗粒表面，以创建柔性和导电共连续网络以及具有应变硬化性能的纳米结构材料。这里使用的合成方法将促进复杂聚合物结构的原位形成，并将产生层次有序的材料，其中聚合物和纳米颗粒域从纳米尺度组织到微米尺度。聚合过程中的x射线和中子散射、振荡剪切动态力学光谱和介电弛豫光谱表征方法将揭示自组装机制，并为设计分层有序的材料提供基础见解。结合原位聚合和结构表征来研究结构-性能关系，将为模拟自然系统和同时利用性能组合的非平衡处理建立基础科学，这在目前的混合聚合物/无机材料中是不可能的。该奖项反映了美国国家科学基金会的法定使命，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。

Part 1: NON-TECHNICAL SUMMARYAchieving simultaneous maximization of contrasting materials properties such as toughness and modulus is a daunting challenge for single-component materials. Biology is able to diverge from the inherent limitations of single-component materials by hierarchically organizing multiple components (biopolymers and minerals) with disparate physical properties. The static structure and hierarchical order of biomaterials is only part of the story; biology and living systems create complex materials through nonequilibrium processes. The goal of the CAREER proposal is to investigate nonequilibrium chemical functionalization and self-assembly methods to create multifunctional hybrid polymeric/inorganic materials. Two polymer/nanoparticle material systems will be explored: 1) flexible and electrically conductive co-continuous networks and 2) nanostructured materials exhibiting exceptional strain-stiffening mechanical properties. Establishing and integrating nonequilibrium chemical processes into materials design will potentially lead to new materials with applications in infrastructure, transportation, health care, and information processing. The research aims of the proposal will be integrated into teaching methods by: 1) developing polymer/materials science modules and labs for professors at nondoctorate-granting institutions within Pennsylvania to augment the undergraduate curriculum and 2) creating open-access video-standard operating procedures (VSOP) for all interested researchers to learn detailed methods for polymer synthesis, sample preparation, and characterization.Part 2: TECHNICAL SUMMARYThe hybrid polymer/inorganic materials field has been working under the premise that equilibrium concepts will lead to the complex materials seen in nature, yet biology utilizes nonequilibrium processes to create biomaterials. The overarching aim of the proposal is to identify design criteria using nonequilibrium chemical functionalization and self-assembly methods to create multifunctional hybrid polymeric/inorganic materials via polymerization-induced nanostructural transitions. In this research, in-situ polymer grafting and in-situ block polymer synthetic methods from polymers attached to nanoparticle surfaces will be used to create flexible and electrically conductive co-continuous networks and nanostructured materials exhibiting strain-stiffening properties. The synthetic approach used here will facilitate complex polymer architecture formation in situ and will generate hierarchically ordered materials in which polymer and nanoparticle domains are organized from the nanometer to the micrometer scale. Characterization methods using X-ray and neutron scattering, oscillatory shear dynamic mechanical spectroscopy, and dielectric relaxation spectroscopy during polymerization will reveal the self-assembly mechanism, and lead to fundamental insight for designing hierarchically-ordered materials. Merging in-situ polymerization and structural characterization to investigate structure-property relationships will establish foundational science in nonequilibrium processing that mimics natural systems and harnesses simultaneous property combinations, which are not currently possible in hybrid polymer/inorganic materials.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.