Cotton fabrics with high value fluorescent and hydrophobic
properties
are highly needed in the functional textile industry. A facile method
of imparting fluorescent and hydrophobic characteristics to cotton
fabrics was developed through the application of novel fluorescent
molecules in this work. Three 1,8-naphthalimide fluorescent dyes (FH1,
FH2, FH3) with carboxyl reactive groups and different lengths of aliphatic
carbon chains were synthesized and characterized first. The N,N-carbamide diimidazole-catalyzed esterification
reaction was employed to fix fluorescent dyes covalently on the cotton
fabrics. The morphologies and microstructures of the functional fabrics
were characterized. The apparent color, fluorescence emissions, and
hydrophobic properties of the three molecule-modified fabrics were
investigated and compared. The FH3-modified fabric exhibited strong
yellow-green fluorescence and achieved a water contact angle of 127°,
being outstanding in separating hydrocarbons from water. The hydrophobic
performance originated from the hydrophobic layer formed on the surface
of the fabric by the long carbon chain was verified by theoretical
calculations. This way of constructing fluorescent and hydrophobic
cotton fabrics is promising in green and functional textile manufacturing
without using fluorine compounds and complex preparation processes.