posted on 2024-06-18, 14:04authored byJun Nakagawa, Seiya Morinaga, Yoshiro Kaneko
In this study, we
prepared antifog hard coatings by heating a mixture
of carboxy-functionalized polyhedral oligomeric silsesquioxane (POSS-C)
and oligo(ethylene glycol)s (OEGs, HO(CH2CH2O)nH, n = 1–6)
in N,N-dimethylformamide, applying
the mixture onto a glass substrate, and subsequently removing the
solvent via heating. In addition, we evaluated the water resistance,
hardness, and antifogging performance of the coatings. In particular,
the coating produced at a 2:1 functional group ratio of POSS-C to
tetraethylene glycol (OEG, n = 4) coating exhibited
high surface hardness (6H), as determined using pencil scratch testing.
The coating remained clear after exposure to the vapor of warm water
at 40 °C at a height of 2 cm for 10 s, demonstrating its antifogging
property. Furthermore, no dissolution or cracking was observed when
the POSS-C/OEG coating (n = 4, COOH/OH = 2:1) was
immersed in water at room temperature for 1 h, confirming its water
resistance. The Fourier transform infrared/attenuated total reflectance
results showed the formation of ester bonds, indicating the construction
of a network structure that enhanced the water resistance and hardness
of the coating.