14:00 〜 14:15
▲ [19p-231B-3] How Laser-Generated Surfactant-Free Particles Evolve in Presence of and in Absence of SU-8 Photoresist Molecules
キーワード：laser ablation in liquids, size control
The technique of laser ablation in liquids (LAL) has already demonstrated its flexibility and capability for the synthesis of a large variety of surfactant-free nanomaterials with high purity [1]. However, high purity can cause trouble for nanomaterial synthesis because active high-purity particles can spontaneously grow into different nanocrystals [2], which makes it difficult to accurately tailor the size and shape of the synthesized nanomaterials. Two options of laser modulation and surface chemistry manipulation are available for size control [1]. The particles obtained by laser modulation are still surfactant-free, which inevitably induces particle growth. Hence, tailoring the colloidal surface chemistry by ex situ functionalization would be a better solution to accurately control the particle size.
Recently, we observed that ultrasmall Ag nanoparticles (NPs) which are generated by femtosecond laser ablation in acetone (457 fs, 1045 nm, 100 kHz, 300 mW and 600 mW) grow into polygonal nanocrystals accompanied by an increase in the particle size during storage of the colloid for 6 months [3]. However, the aged Ag NPs still have a broad size distribution between 1 nm and 200 nm with an average size of ca. 5.9 nm and polydispersity (σ) of 127-207%, suffering from large polydispersity. After SU-8 functionalization and 6 month storage, most particles larger than 10 nm become aggregates and precipitate, which makes the distribution narrower with an average diameter of 4-5 nm and σ of 48-78% [4].
Recently, we observed that ultrasmall Ag nanoparticles (NPs) which are generated by femtosecond laser ablation in acetone (457 fs, 1045 nm, 100 kHz, 300 mW and 600 mW) grow into polygonal nanocrystals accompanied by an increase in the particle size during storage of the colloid for 6 months [3]. However, the aged Ag NPs still have a broad size distribution between 1 nm and 200 nm with an average size of ca. 5.9 nm and polydispersity (σ) of 127-207%, suffering from large polydispersity. After SU-8 functionalization and 6 month storage, most particles larger than 10 nm become aggregates and precipitate, which makes the distribution narrower with an average diameter of 4-5 nm and σ of 48-78% [4].