[9p-PA6-1~9] 12.2 Characterization and Materials Physics

[9p-PA6-1] Measurement of the Mechanical Strength of Single- and Multi-layered Metal Nanoparticle Sheets on Soft Polymer Substrates by Nano-indentation

〇PANGPANG WANG¹, KAORU TAMADA², SUNAO YAMADA¹ (1.ISIT, 2.Kyushu Univ.)

Keywords:nanoparticle, nano-indentation, Atomic force microscope

In this work, we report the measurement of the mechanical strengths of monolayers comprising silver and gold nanoparticles (AgNPs and AuNPs) on soft polymer substrates by using the nano-indentation method based on atomic force microscopy (AFM). The synthesized silver nanoparticles (5 nm silver core capped with myristic acid) and gold nanoparticles (10 nm gold core capped with oleylamine) were both mono-dispersible into toluene. The metal nanoparticles can be self-assembled to form monolayers (single nanoparticle thick) at the air-water interface after the solvent evaporated in terms of Langmuir method. By compressing the monolayers of metal nanoparticles to proper surface pressure, a large area of uniform monolayer of metal nanoparticles can be obtained at the air-water interface. Then, the monolayer of metal nanoparticles can be transferred onto hydrophobic solid substrate by using Langmuir-Schaefer method. Here, we used the freshly prepared polydimethylsiloxane (PDMS) as substrate to deposit the metal nanoparticles monolayer. By using such method, it is easily to form multilayered nanoparticles layers. We have fabricated PDMS stamps of different hardness by tuning the ratio of monomer to curling agent as well as the aging temperature. The mechanical strength of the metal nanoparticle layers transferred onto the PDMS substrate were measures using AFM nano-indentation by using cantilevers with different spring constants.