Antioxidant Monolayer Formation by C14

Langmuir-Blodgett studies was carried out for compound C14, being the ultimate compound with both surface active and antioxidant properties, according to the method of Correa et al.^{29 (link)} with slight modications. Experiments were performed in aqueous solutions at neutral pH. Briefly, 20 µl of 2 mg/mL solution of C14 in chloroform:methanol (9:1, v/v) was applied to the aqueous phase and allowed to evaporate for a period of 20 min. Thereafter, the barriers were compressed at a constant rate of ~9 Å/ (chain min) until film collapsed. After stable conditions were attained, deposition of the corresponding film was carried out onto a hydrophilic mica support at a pressure just before film collapsed. The deposited monolayers on mica were left to air dry overnight. AFM images were acquired at ambient conditions by air tapping mode using a silicon tip on a micro cantilever (Olympus Inc., Japan) with a spring constant of 26 N/m and resonant frequency of 300 kHz. All measurements were performed in the center of the sample. Analyses were done in duplicates.