纳米粒子 - 聚合物复合材料使用直接荧光成像的先进成分分析
Summary
Here we present a reliable method to monitor the incorporation of nanoparticles into a polymer host matrix via swell encapsulation. We show that the surface concentration of cadmium selenide quantum dots can be accurately visualized through cross-sectional fluorescence imaging.
Abstract
The fabrication of polymer-nanoparticle composites is extremely important in the development of many functional materials. Identifying the precise composition of these materials is essential, especially in the design of surface catalysts, where the surface concentration of the active component determines the activity of the material. Antimicrobial materials which utilize nanoparticles are a particular focus of this technology. Recently swell encapsulation has emerged as a technique for inserting antimicrobial nanoparticles into a host polymer matrix. Swell encapsulation provides the advantage of localizing the incorporation to the external surfaces of materials, which act as the active sites of these materials. However, quantification of this nanoparticle uptake is challenging. Previous studies explore the link between antimicrobial activity and surface concentration of the active component, but this is not directly visualized. Here we show a reliable method to monitor the incorporation of nanoparticles into a polymer host matrix via swell encapsulation. We show that the surface concentration of CdSe/ZnS nanoparticles can be accurately visualized through cross-sectional fluorescence imaging. Using this method, we can quantify the uptake of nanoparticles via swell encapsulation and measure the surface concentration of encapsulated particles, which is key in optimizing the activity of functional materials.
Introduction
纳米材料的应用曾长期担任增加对新技术感兴趣的一个领域。1-3这包括越来越多地使用的日常用品，包括化妆品，服装，包装，电子纳米粒子的4-6倾向于使用纳米颗粒的主要驱动器在功能性材料从较高相对于材料它们的反应性茎，除了在颗粒尺寸的能力来调整属性由变异7另一个优点是容易地形成的复合材料的能力，引入关键属性的基质，如催化功能材料的强化和电性能的调优。8-12
其中最简单的纳米颗粒-聚合物复合材料可通过一系列的技术来实现，是基质的制造过程中直接整合所需的纳米粒子。13,14该Results在均质材料均匀间距的纳米材料贯穿始终。然而，许多应用仅仅要求活性物质存在于纳米复合材料的外部接口。其结果是，直接掺入不导致有效地使用有时昂贵纳米材料作为存在通过散装的材料的多纳米颗粒废物。15,16为了实现直接掺入，纳米颗粒还必须与主体基质形成兼容。这可能是具有挑战性的，尤其是在要求多面的反应，如在通常由可以由高活性的纳米颗粒的影响金属配合物催化剂的机制促进热固性聚合物的情况下合成。14
聚合物合成过程中直接纳米粒子掺入相关联的相当大的缺点，已导致的技术旨在限制纳米颗粒incorporati发展到表面层。17-21胀大封装是在文献中报道的最成功的策略之一，以实现高的表面的纳米粒子的浓度，与在聚合物本体有限浪费。17-19该技术利用聚合物的溶剂从动溶胀矩阵，允许分子种类和纳米颗粒的侵入。在除去溶胀溶剂，在基质内的物种成为固定到位，以在表面局部物种的浓度最高。迄今为止，大多数膨胀包封的报道使用均朝向抗微生物聚合物的制造中，在那里它是关键的活性剂是在该材料的表面上。虽然许多这些报告显示增强的抗菌活性，精确的表面的纳米颗粒组合物进行详细很少探测。克里克等人最近证明为纳米粒子侵入的直接可视化的方法，提供了重要的INSIGHT成涌浪封装实现动力学和表面的纳米颗粒的浓度。22
这个工作详细硒化镉量子点（QD），其溶胀封装到聚二甲基硅氧烷（PDMS），并使用荧光成像它们掺入的直接可视化的合成。变溶胀封装时间和纳米粒子的浓度在溶胀溶液的效果进行了探索。荧光可视化技术允许纳米粒子侵入的直接成像到PDMS并表明量子点的最高浓度是在该材料的表面上。
Protocol
Representative Results
Discussion
Cross-sectional fluorescence imaging allows for direct visualization of nanoparticles during swell encapsulation. The kinetics of encapsulation has been shown, with the drive toward a high nanoparticle surface concentration demonstrated. The extent of nanoparticle incorporation is shown to vary with swell encapsulation time (described in section 2.3), with the total amount of incorporated nanoparticles increasing as this time is extended, with the particle concentration localized at the surface if the polymer samples are…
Disclosures
The authors have nothing to disclose.
Acknowledgements
C.R.C. would like to acknowledge the Ramsay Memorial Trust for funding.
Materials
| Polydimethylsiloxane sheets | NuSil | – | Medical Grade |
| Oleylamine | Sigma Aldrich | O7805 | Technical Grade |
| Trioctylphosphine | Sigma Aldrich | 117854 | Technical Grade |
| Trioctylphosphine oxide | Sigma Aldrich | 346187 | Technical Grade |
| 1-Octadecene | Sigma Aldrich | O806 | Technical Grade |
| Zinc diethyldithiocarbamate | Sigma Aldrich | 329703 | – |
| Oleic acid | Sigma Aldrich | 364525 | Technical Grade |
| Triethylamine | Sigma Aldrich | 471283 | – |
| Cadmium oxide | Alfa Aesar | 33235 | – |
| Hexadecylamine | Alfa Aesar | B22459 | Technical Grade |
| 1-Dodecylphosphonic acid | Alfa Aesar | H26259 | – |
| Selenium powder | Acros | 19807 | – |
| Chloroform | Sigma Aldrich | 366919 | – |
| n-Hexane | Sigma Aldrich | 208752 | – |
| Microscope slides | VWR | 631-0137 | Thickness No. 1 |
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