Corrosion Behavior of Aluminum Flakes Coated by Silica/Poly(Acrylic Acid) Nanolayers

In this work, the protection of aluminum pigments from corrosion phenomenon has been extended by meansof an encapsulating polystyrene/silica hybrid nanolayer. A silica nanolayer was encapsulated the surface of flakes bypolycondensation of tetraethylorthosilicate (TEOS) via sol-gel process (Al/Si). Then, 3-methacryloxypropyltrimethoxysilane (MPS) was used as surface modifier which has polymerizable groups to participatein polymerization reaction (Al/Si/MPS). A polystyrene (PS) coating was applied on Al/Si pigment flakes bypolymerization of styrene initiating with AIBN (Al/Si/PS). Scanning electron microscopy (SEM) showed that silica andPS layers were formed on the pigment flakes. Also, transmission electron microscopy (TEM) images showed clearly thatthe encapsulating layers are in the scale of nano. Although the Al/Si pigments showed a quantity of evolved hydrogen,the hybrid coated pigments had excellent anticorrosive properties in acidic and alkaline solutions.

Keywords:

Aluminum flakes , Corrosion behavior , Poly(acrylic acid) , Sol-gel method , In situ polymerization