Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Tuning the Photothermal Effect of Carboxylated-Coated Silver Nanoparticles through pH-Induced Reversible Aggregation
Langmuir ( IF 3.7 ) Pub Date : 2020-11-10 , DOI: 10.1021/acs.langmuir.0c02528 Nancy M. Cativa 1 , Ignacio E. dell’Erba 1 , Carolina V. Waiman 2 , Gustavo F. Arenas 3 , Marcelo Ceolín 4 , Lisandro J. Giovanetti 4 , José M. Ramallo-López 4 , Guillermo Eliçabe 1 , Cristina E. Hoppe 1
Langmuir ( IF 3.7 ) Pub Date : 2020-11-10 , DOI: 10.1021/acs.langmuir.0c02528 Nancy M. Cativa 1 , Ignacio E. dell’Erba 1 , Carolina V. Waiman 2 , Gustavo F. Arenas 3 , Marcelo Ceolín 4 , Lisandro J. Giovanetti 4 , José M. Ramallo-López 4 , Guillermo Eliçabe 1 , Cristina E. Hoppe 1
Affiliation
|
The photothermal response of mercaptoundecanoic acid (MUA)-coated Ag nanoparticles (Ag@MUA NPs) in both aqueous dispersions and paper substrates was determined as a function of pH when irradiated with a green laser or a blue LED source. Aqueous dispersions of Ag@MUA NPs showed an aggregation behavior by acidification that was used for the formation of NPs clusters of variable sizes. Aggregation was induced by changing the pH across the apparent pKa of the acid, higher than the pKa of the free acid. Formation of these aggregates was completely reversible allowing the return to the well-dispersed initial state by simply increasing the pH by the addition of a base. Aggregation produced a shift of the plasmon band that changed the spectra of the dispersions and their ability to be remotely heated when irradiated with visible light. These aggregates could be transferred to paper by simple impregnation of the substrates with the dispersion. On the solid substrate, a higher photothermal response than in the liquid medium was observed. A high local increase of up to 75 °C could be recorded on paper after only 30 s of irradiation with a green laser, whereas a blue LED array was enough for inducing the melting of a solid paraffin (Tm = 36–38 °C) deposited on it. This work demonstrates that photothermal heating can be controlled by the reversible aggregation of NPs to induce different thermal responses in liquid and solid media.
中文翻译：
通过pH诱导的可逆聚集来调节羧化包覆的银纳米粒子的光热效应
当用绿色激光或蓝色LED光源照射时，测定了水分散体和纸张基材中巯基十一酸（MUA）包覆的Ag纳米颗粒（Ag @ MUA NPs）的光热响应与pH的关系。Ag @ MUA NPs的水分散体通过酸化表现出聚集行为，用于形成可变大小的NPs簇。聚集诱导通过在明显的p改变pH ķ一个酸的，比p更高ķ一个游离酸。这些聚集体的形成是完全可逆的，可以通过添加碱来简单地增加pH值，从而恢复到良好分散的初始状态。聚集产生等离激元带的移动，其改变了分散体的光谱及其在可见光照射下被远程加热的能力。这些聚集体可以通过用分散体简单地浸渍基材而转移到纸上。在固体基质上，观察到比在液体介质中更高的光热响应。仅用绿色激光照射30秒后，纸上的局部最高升高到75°C，而蓝色LED阵列足以诱导固体石蜡（T m= 36–38°C）。这项工作表明光热加热可以通过NP的可逆聚集来控制，从而在液体和固体介质中诱导不同的热响应。
更新日期：2020-11-10
中文翻译：
通过pH诱导的可逆聚集来调节羧化包覆的银纳米粒子的光热效应
当用绿色激光或蓝色LED光源照射时，测定了水分散体和纸张基材中巯基十一酸（MUA）包覆的Ag纳米颗粒（Ag @ MUA NPs）的光热响应与pH的关系。Ag @ MUA NPs的水分散体通过酸化表现出聚集行为，用于形成可变大小的NPs簇。聚集诱导通过在明显的p改变pH ķ一个酸的，比p更高ķ一个游离酸。这些聚集体的形成是完全可逆的，可以通过添加碱来简单地增加pH值，从而恢复到良好分散的初始状态。聚集产生等离激元带的移动，其改变了分散体的光谱及其在可见光照射下被远程加热的能力。这些聚集体可以通过用分散体简单地浸渍基材而转移到纸上。在固体基质上，观察到比在液体介质中更高的光热响应。仅用绿色激光照射30秒后，纸上的局部最高升高到75°C，而蓝色LED阵列足以诱导固体石蜡（T m= 36–38°C）。这项工作表明光热加热可以通过NP的可逆聚集来控制，从而在液体和固体介质中诱导不同的热响应。
京公网安备 11010802027423号