Influence of 3-aminopropyltriethoxysilane/tetraethylorthosilicate mixture pretreatment on the microstructure and corrosion resistance of zeolite coating

ABSTRACT

The influence of silane pretreatment with five different volume ratios (100/0, 75/25, 50/50, 25/75, and 0/100) of 3-aminopropyltriethoxysilane (APTES)/tetraethylorthosilicate (TEOS) on microstructure and corrosion resistance of the hydrothermal synthesized zeolite coatings on the H13 steel substrates was investigated. The surface of the zeolite coatings on the 100/0, 75/25, and 50/50 mixture of the APTES/TEOS pretreated substrates was composed of intergrown rectangular particles. Additionally, pores were observed. A 25/75 mixture of APTES/TEOS pretreatment smoothed the edges and angles of zeolite particles with gel-like materials filled in the pores. In pure TEOS pretreatment, microcracks, and much gel-like materials were observed on the zeolite coating. The electrochemical test revealed that the zeolite coating on a 50/50 mixture of the APTES/TEOS pretreated substrate exhibited the highest corrosion resistance in 3.5 wt-% NaCl solution. This was because a 50/50 mixture of APTES/TEOS pretreatment advantageously promoted development of a dense and thick gel layer, which enhanced the intergrowth of zeolite particles.

KEYWORDS:

• Silane pretreatment
• H13 die steel
• zeolite coating
• corrosion resistance
• tetraethylorthosilicate
• microstructure
• electrochemical impedance spectroscopy
• scanning electron microscope

Acknowledgement

This work was supported by the National Key Research and Development Program of China (grant 2017YFB0306301).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by National Key Research and Development Program of China [Grant Number 2017YFB0306301].