Chromium-Free Anti-Fingerprint Coating

A polymer coating whose degradation mechanism shifts from ultraviolet-dominated to fungal-dominated when exposed to tropical rainforest environments.

Shuyuan, Zhang · Liu, Qianqian · Yanwen, Hu · Hao, Xiangping · Lu, Lin · Zhang, Dawei

Materials and Design 2026

Specifications

Gloss loss

{'zh': '10.45', 'en': '10.45'} %

Low-frequency impedance modulus (|Z|0.01 Hz)

{'zh': '10⁴', 'en': '10⁴'} Ω·cm²

C–O–C bond absorption peak intensity

{'zh': '0.03', 'en': '0.03'}

Amide II band absorption peak intensity

{'zh': '0.04', 'en': '0.04'}

Gloss loss after prolonged exposure

{'zh': '42.07', 'en': '42.07'} %

Advantages

Initial photodegradation resistance

UV radiation activates Si–O–Si bonds, causing hydrolysis to unstable Si–OH that re-crosslinks into highly condensed Si–O–Si, providing a protection effect and limiting gloss loss to 10.45% in the first six months.

Reveals fungal degradation indicators

Monitoring the drop in low-frequency impedance modulus from 10⁵ to ~10⁴ Ω·cm² and the appearance of inductive elements enables early identification of micropore formation and corrosion product accumulation, providing early failure warning.

Applications

• Weathering-Resistant Coating Design：Clarifies the synergistic degradation pathways of UV and fungi, guiding design to stabilize polyurethane bonds against fungal attack.
• Composite Surface Protection：Reveals micropore formation and impedance drop trends, providing key indicators for life prediction of composite surface protection layers.
• Outdoor Equipment Coatings：Simulates real tropical rainforest exposure, aiding screening of outdoor equipment coatings resistant to both fungi and UV.
• Corrosion Protection Engineering：Monitors corrosion product accumulation beneath coatings via impedance spectroscopy, offering early failure warning for corrosion protection.