Tomiko Fujii

Studies on applications of lipolytic enzyme in detergency I. Effect of lipase fromCandida cylindracea on removal of olive oil from cotton fabric

To investigate the effect of lipolytic enzyme on removal of triglyceride soils in laundry, the removal of olive oil from cotton fabric was examined by washing with an aqueous solution of lipase fromCandida cylindracea with and without surfactants at various washing temperatures and times.It was proved that, at optimum conditions, the removal of olive oil with the addition of lipase was 15 to 20% higher than without lipase. Therefore, it might be expected that lipase will be applied in the laundry detergents in practice.

Quantitative determination of Tri-, Di-,monooleins and free oleic acid by the thin layer chromatography-flame lonization detector system using internal standards and boric acid impregnated chromarod.

The separation conditions for hydrolysates of triglycerides by lipase and their quantitative determination are discussed for a thin layer chromatography-flame ionization detector system utilizing internal standards. The complete separation of glyceride hydrolysis mixtures (triolein 1,3-diolein, 1,2-diolein, 1-monoolein and oleic acid) was achieved on a 3% boric acid-impregnated Chromarod S-II by development with benzene/chloroform/acetic acid (70∶30∶2, v/v/v) (mobile phase A) or hexane/ ether/acetic acid (70∶30∶1, v/v/v) (mobile phase B). Mobile phase B had an advantage over mobile phase A in terms of free space to add internal standards for simultaneous quantitation and was employed.p-Hydroxybenzoic acid andp-carboethoxy benzyl alcohol, which appeared between 1,2-diolein and 1-moloolein, were adopted as the internal standards. The calibration curves relating internal standards to each glyceride were all approximated by the equations Y=aXb giving high correlations. The method was applied to hydrolysis of triolein by pancreatic lipase.

Studies on applications of lypolytic enzymes in detergency II. Evaluation of adaptability of various kinds of lipases in practical laundry conditions

Kinetic parameter of hydrolysis, degree of hydrolysis, pH and temperature characteristics and positional specificity of hydrolysis of seven kinds of lipases from various microorganisms and a pancreatic lipase were examined for triolein or olive oil emulsion as a substrate and the adaptability of lipases for laundry systems was evaluated on the basis of these properties.As a result, it was found that lipases from yeast ofCandida cylindracea (Lipase MY® and OF®) were excellent in kinetic parameter and degree of hydrolysis and temperature characteristics and had no positional specificity, and that lipases from mold ofMucor (Lipase M-AP® and SP®) were excellent in pH and temperature characteristics and had positional specificity. On the viewpoint of the present laundry practice under alkaline conditions and the tendency toward low temperature washing, lipases fromCandida andMucor seem to be more suitable for laundry systems in comparison with lipases from other microorganisms and a pancreatic lipase.The effect of positional specificity in hydrolysis of lipase will be discussed on the basis of examination on the removal of triglyceride and its hydrolysates by surfactant solution in a subsequent paper.

Fluoroalkylation of polyester by end-capped fluoroalkyl-functional silanes

The surface modification of polyester was examined using both monomeric and oligomeric silanes having end-capped fluoroalkyl groups. From contact angle measurements, the surface free energies of polyester were reduced to 15-20 mJ/m2 for the dispersive component and 1 -3 mJ/m2 for the polar component, respectively, and all the surfaces were shown to be both highly water- and oil-repellent. By XPS (X-ray photoelectron spectroscopy) measurements, using the C l.s peak attributable to the C=O of polyester, the thickness of the siloxane layer on the surface was shown to be less than 5 nm. The solvent durability (resistance) of the modified surfaces was evaluated using contact angle and XPS measurements. Although all the modified surfaces showed durability against dodecane, xylene, ethyl acetate, tetrachloroethylene, and hydrochloric acid, long-time immersion in fluorine-containing solvents reduced the oil repellency of some of the surfaces modified with monomeric or oligomeric silanes having short fluoroalkyls....

Repellency of Textile Assemblies Part I: Apparent Contact Angle of Wax-Coated Monofilament Mesh Screen

In a series of studies on the wettability of textile assemblies, apparent contact angles (ϕ) of wax-coated monofilament nylon and polyester mesh screens to water were measured to investigate the effect of the woven structure on the repellency of textiles. Expressions for the liquid-solid and liquid-air interfaces per unit of macroscopic surface area in the Cassie-Baxter equation (f 1 and f2, respectively) have been derived for mesh screens using several models to calculate the apparent contact angles (ϕ A ) theoretically. Comparison with experimental data has shown that the apparent advancing contact angles of water on wax-coated mesh screens can be quantitatively predicted by the Cassie-Baxter equation when the geometrical structure of the surface is accurately defined.

Effects of Grafting with Acrylic Acid on Removal of Oily Soil from Polyester Fabric

In a series of studies on the effects of modifying textiles for soil release properties, polyester fabrics were grafted with acrylic acid to vary their surface energies while changing their bulk properties as little as possible. The surface free energies of grafted polyester fabrics were estimated using the relationship between the polar component of surface energies γs p and the peak area ratios of COONa (1580 cm-1) to COOR (1250 cm-1) by FT-IR measurements. The effects of grafting on soil release were also investigated with washing experiments using squalane, triolein, and oleic acid as oily soils. The effects of grafting on oily soil removal varied depending on the polarity of soil. Results are discussed in terms of the work of adhesion between oil and polyester fabric.

Studies on Removal of Fatty Soil from Cotton Fabrics

Effects of concentration of sodium dodecyl sulfate and the washing temperature on the removal of palmitic acid as a model of fatty soil from cotton fabrics were studied. In addition, the effect of the addition of lower n-fatty alcohols (C2•`C6) to the surfactant on the removal of the fatty soil was also studied. At the washing temperature below the melting point of palmitic acid, the removal of palmitic acid is only small in the vicinity of critical micelle concentration of sodium dodecyl sulfate but is very remarkable in the 10 times higher concentration than c.m.c. At the washing temperature higher than the melting point of palmitic acid, the removal was easy at the vicinity of the c.m.c. of sodium dodecyl sulfate. The removal amount of palmitic acid from cotton fabrics at the higher concentration than the c.m.c. was less than the saturated solubilized amount of the soil at the same concentration. Therefore, the complete removal by the mechanism of solubilization only would be impossible. The addition of fatty alcohols to sodium dodecyl sulfate solution was effective to increase the removal of palmitic acid. The longer the alkyl chain of the alcohol was the more effective in lesser amount of the addition.