Synthesis and Self-Assembly of Amphiphilic Nanoparticles Based on Block Copolymers of Functionalized Vinylbenzocyclobutenes

基于官能化乙烯基苯并环丁烯嵌段共聚物的两亲性纳米粒子的合成与自组装

• 批准号: 1006195
• 负责人: Coleen Pugh
• 金额: $ 53万
• 依托单位: University of Akron
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-03-01 至 2016-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1006195&HistoricalAwards=false
• 关键词: Synthesis; Self; Assembly; Amphiphilic; Nanoparticles

TECHNICAL SUMMARYNanoparticles must be ordered into complex arrays with the control and reproducibility of biological systems for both nano- and biotechnology applications. Although asymmetrically functionalized nanoparticles are expected to self-assemble directly into complex structures without the need for template assistance, most nanoparticles are spherical in shape with isotropic surfaces. A new route is therefore proposed to synthesize relatively rigid, amphiphilic organic nanoparticles with rod or dumb-bell and tripod shapes for self-assembly into 1-D, 2-D, and/or 3-D superstructures, using amphiphilic block copolymers based on 1-functionalized vinylbenzocyclobutenes in which each of the vinylbenzocyclobutene-containing blocks undergoes isomerization at a significantly different temperature. The amphiphilic nanoparticles will therefore be fabricated step-wise by separate intramolecular crosslinking steps under pseudo-high dilution conditions in solvents that selectively solvate the non-crosslinking block(s). The lengths of the blocks will control the size of the lobes, and the nanoparticles are expected to be in the 5-20 nm size range. The intramolecular crosslinking reaction will be monitored by the disappearance of the resonances of the benzocyclobutene rings by NMR spectroscopy, and the change in the size and shape of the polymers/nanoparticles will be followed by gel permeation chromatography, light scattering, transmission electron microscopy (TEM), and/or atomic force microscopy (AFM) of samples prepared by a "fossilized liquid assembly" technique. Atomic force microscopy of "fossilized" samples will be used to determine the shapes of individual nanoparticles, and variations in their chemical composition as well as shape will be determined by TEM, scanning TEM and surface-enhanced raman spectroscopy; these techniques will also be used to characterize their self-assembled structures at a liquid-liquid interface or on a solid substrate.NON-TECHNICAL SUMMARY Particles that are small enough to be considered nanoparticles have unique properties compared to larger particles. These unique properties are leading to unique applications, which has led to the field of "nanotechnology". However, to make major advances in nanotechnology applications, the nanoparticles must be able to order into complex structures. Although complex structures can be generated by placing the nanoparticles on a surface with that complex pattern already built into it, computer studies have shown that nanoparticles should be able to order on a non-patterned surface if the particles themselves have complex shapes and/or complex surface properties. For example, if half of the nanoparticle surface likes water and the other half repels water, those two parts of the particle will only interact with similar parts on surrounding particles, such that their organization is directed or restricted by their similarities and differences. A new route is therefore proposed to create nanoparticles that have complex shapes, such as dumbbell and tripod shapes, in which each of their lobes have different surface properties. The different parts of the nanoparticle will be created stepwise using chemistry that reacts at a different temperature for each of the different lobes. These new nanoparticles will provide real materials to test theories that predict how nanoparticles organize when they have unusual shapes and varying surface properties. The proposed research will train student researchers in the increasingly important area of nanotechnology, simultaneously with requiring mastery of fundamental chemistry and physics. Undergraduate students will participate in this research program during the summer through an REU (research experience for undergraduates) position, in the NSF-sponsored REU Site for Polymer Science and Engineering at The University of Akron. In addition, a Special Interest Fair will be established for K-5 students at King Elementary School in Akron.

技术摘要必须订购为复杂的阵列，并具有用于纳米和生物技术应用的生物系统的控制和可重复性。 尽管不对称官能化的纳米颗粒有望直接组装成复杂的结构而无需模板辅助，但大多数纳米颗粒的形状都是各向同性表面的球形。 因此，提出了一条新途径，以将相对刚性的有机纳米颗粒合成，并使用杆或哑铃和三脚架形状和三脚架形状，以将基于1-D，2-D和/或3-D上层结构组合成1-D，2-D和/或3-D上层结构，并使用基于1官能化的vinyly-cocterence-contermentialized blockhilic Block copoler块在明显不同的温度下经历异构化。因此，两亲性纳米颗粒将通过在溶剂中伪高稀释条件下的单独分子内交联步中进行逐步制造，从而选择性地溶解了非跨链接块。块的长度将控制裂片的大小，预计纳米颗粒在5-20 nm尺寸范围内。 The intramolecular crosslinking reaction will be monitored by the disappearance of the resonances of the benzocyclobutene rings by NMR spectroscopy, and the change in the size and shape of the polymers/nanoparticles will be followed by gel permeation chromatography, light scattering, transmission electron microscopy (TEM), and/or atomic force microscopy (AFM) of samples prepared by a "fossilized liquid组装”技术。 “化石”样品的原子力显微镜将用于确定单个纳米颗粒的形状，其化学成分和形状的变化将由TEM，扫描TEM和表面增强的拉曼光谱确定。 这些技术还将用于表征其在液体液体界面或固体底物上的自组装结构。与较大颗粒相比，它们足够小，足以被认为是纳米颗粒具有独特的特性。 这些独特的属性导致了独特的应用，这导致了“纳米技术”领域。 但是，为了在纳米技术应用方面取得重大进展，纳米颗粒必须能够订购复杂的结构。 尽管可以通过将纳米颗粒放在已经内置的复杂模式的表面上来产生复杂的结构，但计算机研究表明，如果粒子本身具有复杂的形状和/或复杂的表面特性，则纳米颗粒应该能够在非图案表面上订购。 例如，如果一半的纳米颗粒表面喜欢水，而另一半则排出水，则粒子的这两个部分只会与周围颗粒上的相似部分相互作用，从而使它们的组织受其相似性和差异的指导或限制。 因此，提出了一条新途径，以创建具有复杂形状的纳米颗粒，例如哑铃和三脚架形状，其中每个叶具有不同的表面特性。 纳米颗粒的不同部分将使用化学反应逐步创建，该化学反应在每个不同的裂片中在不同的温度下反应。 这些新的纳米颗粒将提供真实的材料来测试理论，以预测纳米颗粒具有异常形状和不同表面特性时如何组织。 拟议的研究将培训纳米技术越来越重要领域的学生研究人员，同时需要掌握基本化学和物理学。 本科生将在夏季通过REU（本科生的研究经验）在Akron大学的NSF赞助的聚合物科学与工程学的REU站点中参加该研究计划。 此外，将为阿克伦国王小学的K-5学生建立特别的兴趣博览会。