Collaborative Research: Fabrication and Self-Assembly of Smart Nanoparticles

摘要：克拉克森大学克莱姆森大学合作研究：智能纳米颗粒的制造和自组装项目摘要：智力价值我们提出了一种基于纳米颗粒和球形混合聚合物刷的组合制造智能胶体系统的新方法。混合聚合物刷是指两种不太可能的聚合物的单层接枝到相同的固体基底上。pi成功地使用接枝到固体基板平面上的混合刷来设计智能和响应表面，这些表面可以根据外部信号（溶剂，pH，温度）改变表面组成，界面能，附着力，吸附，润湿行为等。开关/响应行为的机制被证明源于不可能的聚合物的微相偏析，其中外部条件可能强烈影响相偏析。在这个建议中，我们建议将发展的方法转化为一个新的具有挑战性的系统-球形混合刷。两种不太可能的聚合物将末端接枝到同一个球形纳米颗粒上。球面几何给混合刷的相偏析带来了新的方面。在外界刺激下，球形混合刷中的相分离导致几种特征形态：核-壳，反核-壳（聚合物在径向上分离）和双面状形态（两种不太可能的聚合物占据颗粒的不同侧面）。纳米颗粒半径与电刷厚度的比值对其机理有很大影响。这个新的方面将允许我们添加一个新的参数（粒子半径）来调节响应。本研究将对球形电刷在受控外部环境下的相偏析机理进行系统研究。电刷的调节响应将用于调节胶体系统（胶体溶液和悬浮液）中智能颗粒的自组装。外部信号形成超胶束是该项目的第二个目标。来自克拉克森大学和克莱姆森大学的两个合作团队将集中他们的专业知识来合成和研究球形混合刷的分层自组装。更广泛的影响智能纳米颗粒将允许修改体积性质以及材料的表面性质的修改。这种方法的发展对于将纳米科学的最新进展转化为工业技术非常重要，从纳米复合材料到药物输送系统都有广泛的应用。拟议项目的另一个优先事项是让最聪明的高中生、本科生和研究生参与现代表面和纳米技术研究。该项目将培养学生在纳米结构系统的表面改性和表征方面的能力。克莱姆森大学和克拉克森大学的合作也将使学生受益匪浅。此外，他们还将积极参与本项目所计划的国际研究合作。将作出重大努力，增加攻读科学和工程高级学位的学生人数，特别是少数民族和妇女。

ABSTRACT Clarkson University Clemson University0456548 0456550COLLABORATIVE RESEARCH: FABRICATION AND SELF-ASSEMBLY OFSMART NANOPARTICLESPROJECT SUMMARYIntellectual merit We propose a new approach to the fabrication of smart colloidal systems based on a combination of nanoparticles and spherical mixed polymer brushes. Mixed polymer brushes refer to monolayers of two unlikely polymers grafted to the same solid substrate. The mixed brushes grafted onto a plane of solid substrates were successfully used by the PIs to design smart and responsive surfaces which change the surface composition, interfacial energy, adhesion, adsorption, wetting behavior, etc upon external signals (solvent, pH, temperature). The mechanism of the switching/responsive behavior was shown to originate from the microphase segregation of unlikely polymers where outside conditions may strongly affect the phase segregation. In this proposal, we suggest the translation of the developed approaches into a new challenging system - spherical mixed brushes. Two unlikely polymers will be end-grafted to the same spherical nanoparticle. The spherical geometry brings new aspects to the phase segregation of the mixed brushes. Upon external stimuli, the phase separation in the spherical mixed brushes results in several characteristic morphologies: core-shell, inverse core-shell (polymers are segregated in the radial direction) and Janus-like morphology (two unlikely polymers occupy different sides of the particles). The mechanism is strongly affected by the ratio between the nanoparticles' radius and brush thickness. This new aspect will allow us to add a new parameter (particle radius) for the regulation of the response. This research will focus on the systematic study of the phase segregation mechanism in the spherical brushes in a controlled outside environment. The regulated response of the brushes will be used to regulate self-assembly of the smart particles in colloidal systems (colloidal solutions and suspensions). Formation of supra micelles upon external signal is the second target of the project. Two collaborating teams from Clarkson University and Clemson University will concentrate their expertise on the synthesis and study of the hierarchical self-assembly of spherical mixed brushes.Broader ImpactThe smart nanoparticles will allow for the modification of bulk properties as well as themodification of surface properties of materials. Development of this approach will beimportant to transform recent advances in nanoscience to industrial technologies with broadapplications from nanocomposites to drug delivery systems. Another priority of the proposedproject is the involvement of the brightest high school, undergraduate and graduate students in the modern surface and nanotechnology research. The project will result in the training of the students in the area of surface modification and characterization of nanostructured systems. Students will also greatly benefit from the collaboration between Clemson and Clarkson Universities. Moreover, they will be actively involved in the international research collaboration that is also planned in this project. Significant effort will be directed to increasethe numbers of students, especially minorities and women, who pursue advanced degrees in science and engineering.