Stability evolution of ultrafine Ag nanoparticles prepared by laser ablation in liquids

Understanding the stability evolution of the silver nanoparticles (Ag NPs) in colloid has great benefits for its controllable preparation, storage and application. Herein, uncapped Ag NPs with diameter of 1.66 +/- 0. 37 nm are obtained by laser ablation of Ag target in deionized water, corresponding surface plasma resonance (SPR) bands, zeta potential and particle size distribution are monitored to investigate uncapped Ag NPs' stability evolution. Due to negatively charged surface, uncapped Ag NPs show an excellent dispersion stability in 70 days without any external disturbance. But its dispersion stability and structure stability are destroyed easily by an oscillation treatment, resulting in a tardy growth and the formation of one-dimensional Ag nanochain. In addition, the chemical stability of uncapped Ag NPs is dramatically varied by a displacement reaction with an inserted copper wire. As comparison, two typical cationic and anionic surfactant molecules, N-hexadecyl trimethyl ammonium chloride (CTAC) and sodium dodecyl benzene sulfonate (SDBS) are severally used to prepare surface capped Ag NPs. With same treatment of Ag colloid, both two kinds of capped Ag NPs display better dispersion stability and structure stability than uncapped Ag NPs. Moreover, CTAC capped Ag NPs keep a better chemical stability than SDBS capped Ag NPs. (C) 2020 Elsevier Inc. All rights reserved.

Automated summary

The study investigates the stability evolution of silver nanoparticles in colloid, showing that uncapped Ag NPs exhibit good dispersion stability but are easily disrupted by oscillation treatment, leading to the formation of one-dimensional nanochains. Surface capped Ag NPs with typical cationic and anionic surfactants display better dispersion and structure stability compared to uncapped Ag NPs, with CTAC capped Ag NPs showing superior chemical stability.