Fabrication of Pore-Selective Metal-Nanoparticle-Functionalized Honeycomb Films via the Breath Figure Accompanied by In Situ Reduction.

Yongjiang Li,Jingyu Ma,Fang Chen,Zongwu Zhang,Zhaoqi Niu,Xiaoyan Ma

doi:10.3390/polym13030316

Abstract

Honeycomb films pore-filled with metal (Au, Ag, and Cu) nanoparticles were successfully prepared by combining the breath figure method and an in situ reduction reaction. First, a polyhedral oligomeric silsesquioxane (POSS)-based star-shaped polymer solution containing metal salt was cast under humid conditions for the formation of honeycomb films pore-filled with metal salt through the breath figure method. The morphology of the honeycomb films was mainly affected by the polymer molecular structure and the metal salt. Interestingly, the promoting effect of the metal salt in the breath figure process was also observed. Then, honeycomb films pore-filled with metal nanoparticles were obtained by in situ reduction of the honeycomb films pore-filled with metal salt using NaBH4. Notably, the metal nanoparticles can be selectively functionalized in the pores or on the surface of the honeycomb films by controlling the concentration of the NaBH4. Metal-nanoparticle-functionalized honeycomb films can prospectively be used in catalysis, flexible electrodes, surface-enhanced Raman spectroscopy (SERS), and wettability patterned surfaces.

Highlights

Honeycomb films have attracted considerable interest due to their numerous potential applications in the fields of size-selective separations [1], superhydrophobic surfaces [2], catalysis sensors [3], and so on
Because metal-nanoparticle-functionalized honeycomb films can be used as porous electrodes [3], water correctors [9,10], and surface-enhanced Raman spectroscopy (SERS) substrates [11], there has been much attention focused on preparing metal-nanoparticle-functionalized honeycomb films
Other studies have illustrated the use of mixed solutions of polymers and metal nanoparticles to prepare metal-nanoparticle-functionalized films via the breath figure (BF) method, in which the metal nanoparticles may self-assemble at the polymer solution/water droplet interface and are left in the polymeric pore after the evaporation of the water droplets [20,21,22,23,24,25]

Summary

Introduction

Honeycomb films have attracted considerable interest due to their numerous potential applications in the fields of size-selective separations [1], superhydrophobic surfaces [2], catalysis sensors [3], and so on. By adding metal salt precursors into a polymer solution, metal-oxide-nanoparticle-functionalized honeycomb films were obtained using the breath figure method accompanied by an in situ chemical reaction. Do prepared asymmetrically functionalized poly (ε-caprolactone)/polypyrrole/silver honeycomb films by casting a polymer solution on a reactive ice substrate (containing AgNO3) [34]. Those studies have clearly demonstrated that metal salt has significant effects on the morphology of honeycomb films. The pore-selective filling of metal (Au, Ag, and Cu) nanoparticles in honeycomb films was prepared by combining the breath figure method and an in situ reduction reaction. This work provides a new and facile approach to preparing honeycomb films in which the pores are selectively filled with metal nanoparticles

Materials

Effect of Metal Salt Type and Content on the Morphology of Honeycomb Films