Electrophoretic Coating of Octahedral Molybdenum Metal Clusters for UV/NIR Light Screening

Thi Nguyen,Adèle Renaud,Noée Dumait,Naoki Ohashi,Tetsuo Uchikoshi,Fabien Grasset,Hiroshi Fudouzi,Stéphane Cordier,Benjamin Dierre,Pierric Lemoine

doi:10.3390/coatings7080114

Abstract

Thin and transparent Mo6 cluster films with significant optical properties were prepared on indium tin oxide (ITO)-coated glass plates from the suspension of Cs2Mo6Br14 cluster precursors dispersed in methyl-ethyl-ketone (MEK) by an electrophoretic deposition (EPD) process. Two kinds of polydimethylsiloxanes (PDMS); i.e., KF-96L-1.5CS and KF-96L-2CS corresponding to the kinetic viscosity of 1.5 and 2 centistokes, respectively, were selected to topcoat the Mo6 cluster film after the EPD. The influence of the PDMS on the durability, chemical compatibility and light absorption property of Mo6 cluster films were characterized by means of field-emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FT-IR), and ultraviolet-visible-near infrared (UV-Vis-NIR) spectroscopy. The stabilized PDMS-coated Mo6 cluster film could be stored for more than 6 months under ambient conditions.

Highlights

In recent years, inorganic or organic material-coated glasses exhibiting several special characteristics, such as self-cleaning [1,2], blocking UV-NIR light or generating an electrochromic property [3,4] for a window application, have been intensively studied in order to optimize the specific characteristics and reduce the production costs [5]
Numerous chemical solution deposition (CSD) techniques [13,14] and physical deposition techniques including sputtering and pulsed laser deposition (PLD) [15], which enable the fabrication of nano/micrometer-thick films, have been used in many fields to functionalize the surfaces of a variety of materials
The optimal parameters of the Electrophoretic deposition (EPD) process were determined based on the transmittance, thickness, and homogeneity of the Mo6 cluster films

Summary

Introduction

Inorganic or organic material-coated glasses exhibiting several special characteristics, such as self-cleaning [1,2], blocking UV-NIR light or generating an electrochromic property [3,4] for a window application, have been intensively studied in order to optimize the specific characteristics and reduce the production costs [5]. Metallic plasmonic nanostructures have been the focus for light trapping in energy-harvesting devices due to the processability in fabricating thin films, improving the light absorption and enhancing the pathway of light by scattering and reflecting between metallic layers [6]. Coatings 2017, 7, 114 at wavelengths between 600 and 700 nm [12], the octahedral molybdenum nanocluster precursor ([Mo6 Bi8 La6 ]2− ) has recently been the focus of attention for the application as a glass coating. The PLD process is a versatile coating technique to fabricate thickness and nanostructure-controlled films with less contamination on a substrate [16,17]. The EPD process has been extended to graphene-related materials [24], nanoscale TiO2 [25], or medical materials, i.e., antimicrobial applications [26], bond tissue engineering [27], protein identification [28], and bio-implants [29], based on the possible control of the thickness on a nanometer scale

Methods

Results

Conclusion