Self-Assembly of Polymer Brush Nanoparticles into Porous Supercrystals

多孔材料被广泛应用于从环境修复到生物传感和药物输送的各种应用。创造新型多孔材料的一个挑战是控制毛孔的大小，特别是当所需的大小为数百纳米时，或者说大约1000倍于人类头发的大小。在化学系的大分子、超分子和纳米化学计划以及材料研究部的固态和材料化学计划的支持下，犹他大学的Zharov和Gruenwald教授正在开发设计和创造纳米多孔材料的新策略。他们的方法将聚合物附着在球形纳米颗粒上，然后将其组装成类似于装在盒子里的大理石的超晶体。在实验室中观察到的超晶结构与计算机模拟进行了比较，以更好地了解导致不同材料属性的因素，如孔隙率、强度和灵活性。除了开发制造纳米多孔材料的新方法外，该项目还在合作研究环境中培训研究生和本科生。该研究团队还与当地社区合作，与盐湖城市中心的莱昂纳多博物馆合作，为当地K-12学生开发以能源为重点的活动。该项目专注于制备一系列不同结构的短聚合物刷子纳米颗粒(SPNP)。研究人员正在研究它们的自组装作为SPNP结构参数(即大小、接枝密度、聚合物化学和链长)和组装条件的函数。通过一系列的实验方法，包括透射电子显微镜(TEM)、小角X射线散射(SAXS)和Brunauer？Emmett？Teller(BET)分析，对SPNP组件的结构、力学性能和孔隙率进行了表征。这些实验研究揭示了聚合物刷的参数与所得到的组装超结构的性能之间的相关性。分子动力学计算机模拟，使用高效的粗粒对势，将聚合物链的微观结构与纳米颗粒组装联系起来。此外，计算机模型提供了对实验结果的更深入的理解，因为它们指导了与聚合物刷子相关的参数空间的探索。扎罗夫教授正在盐湖城市中心的博物馆TheLeonardo开发和指导以材料和能源为重点的动手和基于探究的活动，作为与该项目相关的外联活动的一部分。

Porous materials are used extensively in applications ranging from environmental remediation to biosensing and drug delivery. One challenge in creating new types of porous materials is controlling the size of the pores, especially when the desired size is several hundred nanometers, or about 1000 times smaller than a human hair. With the support of the Macromolecular, Supramolecular and Nanochemistry Program of the Chemistry Division and the Solid State and Materials Chemistry Program in the Division of Materials Research, Professors Zharov and Gruenwald at the University of Utah are developing new strategies for designing and creating nanoporous materials. Their approach attaches polymers onto spherical nanoparticles, which are then assembled into supercrystals that resemble marbles packed into a box. The supercrystal structures observed in the laboratory are compared with computer simulations to better understand the factors that give rise to different material properties, such as porosity, strength, and flexibility. In addition to developing new ways to make nanoporous materials, the project trains graduate and undergraduate students in a collaborative research environment. The research team is also engaged in the local community, working with The Leonardo, a museum in downtown Salt Lake City, to develop energy focused activities for local K-12 students.The project is focused on preparing a series of short polymer brush nanoparticles (SPNPs) with varying architecture. The researchers are investigating their self-assembly as a function of SPNP structural parameters (i.e. size, grafting densities, polymer chemistry, and chain length) and assembly conditions. The structure, mechanical properties, and porosity of SPNP assemblies are characterized by a range of experimental methods, including transmission electron microscopy (TEM), small angle X-ray scattering (SAXS), and Brunauer?Emmett?Teller (BET) analysis. These experimental studies shed light on correlations between parameters of the polymer brush and properties of the resulting assembled superstructures. Molecular dynamics computer simulations, using efficient coarse-grained pair potentials, connect the microscopic structure of the polymer chains to the nanoparticle assembly. In addition, the computer models provide a deeper understanding of the experimental findings, as they guide the exploration of the parameter space associated with the polymer brushes. Professor Zharov is developing and directing materials- and energy-focused hands-on and inquiry-based activities at TheLeonardo, a museum in downtown Salt Lake City as part of the outreach activities associated with this project.