直接蛍光イメージングを用いたナノ粒子 - ポリマー複合材料の高度な組成分析
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
ナノ材料の適用は、長い間、新規技術への関心の高まりの面積を務めています。1-3。これは、化粧品、衣類、包装、エレクトロニクスなどの日用品、中のナノ粒子の成長の使用を含んでいた。4-6ナノ粒子を用い向けて主要なドライブ機能材料に、7つ別の利点は、ホストマトリックスに重要な特性を導入する、容易に複合材料を形成する能力である。粒径の変動によって調整プロパティする能力に加えて、材料への高い反応性の相対由来など触媒機能、材料の強化および電気的特性のチューニング。8-12
ナノ粒子-高分子複合材料は、ホストマトリックスの製造中に所望のナノ粒子の直接積分である最も単純なそれらの技術の範囲を介して達成することができる。13,14これR全体にナノ粒子材料の均等間隔で均質な材料でesults。しかし、多くのアプリケーションでは、ナノ複合材料の外部インタフェースに存在する活性物質を必要とします。材料のバルクを通じて多くのナノ粒子の廃棄物が存在する結果として、直接の取り込みは、時には高価なナノ粒子材料の効率的な使用にはなりません。15,16を直接取り込みを達成するために、ナノ粒子はまた、ホストマトリックスの形成と互換性がなければなりません。これは、特に、一般的に高活性なナノ粒子によって影響を受ける可能性がある金属錯体触媒機構によって促進される熱硬化性ポリマーの場合のように多面的な反応を必要とする合成に、挑戦することができる。14
ポリマー合成中に直接ナノ粒子の取り込みに関連したかなりの欠点は、ナノ粒子incorporatiを制限することを目的とした技術の開発につながっています表面層に上。17-21スウェルカプセル化は、ポリマーのバルク中の限られた無駄で、高い表面のナノ粒子の濃度を達成するために、文献で 報告された最も成功した戦略の一つである。17-19技術は、ポリマーの溶剤駆動膨潤を利用します行列は、分子種とナノ粒子の侵入を可能にします。膨潤溶媒を除去すると、マトリックス内の種は表面に局在する種の最高濃度で、所定の位置に固定となります。現在までに、うねりカプセル化の報告用途のほとんどは、活性剤は、材料表面であることが鍵である抗菌ポリマーの製造、に向けられています。これらのレポートの多くが強化された抗菌活性を示しているが、正確な表面ナノ粒子組成物はほとんど詳細に精査されていません。クリックらは最近、重要なINSIを提供し、ナノ粒子の侵入の直接可視化するための方法を実証しましたうねりのカプセル化によって達成動態および表面のナノ粒子の濃度にGHT。22
この作品は、セレン化カドミウム量子ドット（QD）、ポリジメチルシロキサン（PDMS）と蛍光イメージングを使用して、それらの組み込みの直接可視化へのそれらのうねりのカプセル化の合成を詳述します。膨潤溶液中で膨潤カプセル化時間及びナノ粒子の濃度を変化させることの効果が検討されています。蛍光可視化技術は、PDMS中にナノ粒子侵入の直接的なイメージングを可能にし、QDの最高濃度は、材料の表面であることを示しています。
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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