Open AccessImprovement of anti‐tarnishing and anti‐bacterial properties of silver by a waterborne polyurethane/silver nanocomposite coating
Author(s) -
Kazemzadeh Seyed Mohamad,
Hadavi Seyed Mohammad Mehdi,
Vaezi Mohamad Reza,
Esfandeh Masoud
Publication year - 2017
Publication title -
micro and nano letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.25
H-Index - 31
ISSN - 1750-0443
DOI - 10.1049/mnl.2017.0158
Subject(s) - materials science , polyurethane , coating , scanning electron microscope , nanocomposite , transmission electron microscopy , corrosion , substrate (aquarium) , silver nanoparticle , layer (electronics) , tarnish , composite material , energy dispersive x ray spectroscopy , chemical engineering , nuclear chemistry , nanoparticle , nanotechnology , chemistry , oceanography , engineering , geology
Silver (Ag) objects tarnish when expose to the human sweat or atmospheres polluted by sulphide. In this work, a waterborne and transparent polyurethane/Ag (WPU/Ag) nanocomposite was synthesised and applied on the surface of the Ag sample with enhanced anti‐bacterial and also protection against the tarnishing in the corrosive solutions. Ag nanoparticle in the WPU/Ag was investigated by field‐emission scanning electron microscopy and transmission electron microscopy. To study the anti‐tarnishing behaviour of the Ag samples, the bare as well as the coated samples were immersed in corrosion solution of 0.35 wt% Na 2 S which is a simulating solution of the human sweat. The corrosion products were then studied with X‐ray diffraction and energy‐dispersive X‐ray spectroscopy. The bare Ag surface was covered completely by a black layer after 60 min immersion in the corrosion solution. However, the presence of either waterborne polyurethane (WPU) or WPU/Ag coatings was remained on the surface and protected the substrate from tarnishing. Anti‐bacterial properties of the samples were determined by disc diffusion and the minimum inhibitory concentration methods. Anti‐bacterial effect of the Ag coated by WPU/Ag was greater than the bare substrate, whereas the WPU coating lost the anti‐bacterial effect of the Ag substrate.