Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/6/1995
Publication Date: N/A
Interpretive Summary: Most commercial methods for the removal of oil stains require the use of petroleum-based or chlorinated, hazardous chemicals at elevated temperatures. Methods employed to measure stain removal can be time consuming, have associated sample handling problems and often yield erroneous results. In this report a procedure for the removal of soybean oil through the in-situ generation of microemulsions using a nonionic surfactant was developed. Typically, greater than 90% of the oil stain was removed using 2 wt% surfactant. Increasing the amount of surfactant to 6 wt% improved oil removal to 99%. The stain remover is environmentally safe and the composition of surfactant and aqueous phase, used to generate the microemulsion, is capable of removing oil-based stains at room temperature and neutral pH. Nuclear magnetic resonance was found to be a suitable technique for quantifying the removal of lipids from cotton fabrics, required less sample preparation time than traditional methods and was non-destructive. These results will provide fabric manufacturers with a new approach for testing the efficiency of stain removal from textiles.
Technical Abstract: Solubilization and subsequent removal of soybean oil from cotton fabrics through the in-situ formation of microemulsions was evaluated using solid state NMR. Regions of water-in-oil (W/O) and oil-in-water (O/W) microemulsions were identified for systems containing polyoxyethylene (60) sorbitol hexaoleate, soybean oil and an aqueous phase composed of water/ethanol or isopropanol (80/20 wt%) at 25C. The amount of oil removed from the cotton fabrics was determined using solid state nuclear magnetic resonance by constructing a calibration curve relating the intensity of camphor/oil NMR signals (Ic/Io) to their molar ratio (Mc/Mo). A Precision Crockmeter was used to reproducibly remove soybean oil stain from cotton fabric which was subsequently analyzed by NMR. Typically, greater than 90% of the oil stain was removed after 200 revolutions of the Crockmeter finger using 2 wt% surfactant at 25 C. Increasing the amount of surfactant to 6 wt% improved soybean oil removal from the fabric to 99 wt%