The effects of softening agents on the wetting of textiles were investigated by measuring the capillary spreading of liquid as a function of time. The values of the exponent n during phase II of the capillary spreading of softened fabrics increased in comparison with those of unsoftened fabrics owing to the adsorption of the softening agent, which made the fiber surface more hydrophobic and produced a larger advancing contact angle of the fiber to the water (&thetas; A ). Based on experiments with DTAC as a softening agent for nylon, the following quantitative relationship was found between the value of the exponent n and the advancing contact angle of water (&thetas; A ): n = (4.62 X 10 -3 )&thetas; A , -0.001. From this, reasonable advancing contact angles were also estimated for other fabrics.

The surface of polyester grafted with acrylic acid has been characterized using contact angle measurements of a two-liquid phase system and FT-IR and ESCA spectroscopy as a function of the concentration of acrylic acid on grafting. The COOH groups on the polymer surface influence only the polar component γ s p of surface energy and not the dispersive one γ s d . Both the FT-IR and ESCA characterizations, showing the transformation of COOH to COONa by alkaline treatment, provide information with a high degree of surface sensitivity, comparable to that of contact angle measurements. The relative area ratios of the COONa peak to the COOR peak by FT-IR ( A surface ) and of the Na 1 s peak to the C 1 s peak by ESCA are linearly correlated to γ s p .The modification of polymer surfaces is of fundamental importance in adhesion, adsorption, composite materials, etc., and is therefore of considerable practical interest. In textile technology, the surface modification of fibers and fabrics is highly correlated to detergency [ 6, 13 ] and to water and oil repellent finishes [ 7,9].To discuss the effects of surface modifications on textile properties, we must study the changes in surface free energy. For such purposes, both direct and indirect contact angles have been measured using films and fibers [ 10 ] . However, to our knowledge, no direct contact angle measurements on fabrics have been reported so far. Instead, to study the change in the wettability of fabrics, various sorption characteristics have been measured, but these measurements could not directly provide the real contact angles and surface free energies because of heterogeneous capillaries in the fabrics [2][3][4] .In a previous paper [ 5 ], we studied acrylic acid grafting of polyester fabric as an example of chemical soil release finishes. We clarified the intimate co-relationships between the removal of nonpolar oily soil, wettability by water, and surface concentration of COOH groups determined by FT-IR. Note that the fabric properties that greatly depend on surface energy were highly correlated to the surface concentration of COOH groups determined by FT-IR. From that finding we can speculate as follows: If we can find the clear and quantitative relationship between surface energies by contact angle measurements and some results by other surface characterization techniques such as FT-IR and ESCA, we should be able to estimate the surface energies of fabrics based on surface characterization using these relationships as a calibration curve.We have prepared several polyester films of different surface energies by grafting with acrylic acid and characterized these modified surfaces using contact angle measurements and FT-IR and ESCA spectroscopy. This paper focuses particularly on the relationships between surface energy and the characterization results from FT-IR and ESCA. Experimental MATERIALS AND METHODS ..Poly ( ethylene terephthalate) (polyester) film (Toray, Lumilar film 50 pm thick) was grafted with acrylic acid using Ohguchi's met...

In a series of studies on the effects of finishes on textile wetting, the capillary spreading of a liquid drop in fabric was investigated by a photographic technique as a function of time, drop volume, and surface tension/viscosity ratio. The area covered by the spreading liquid was found to be expressed by an exponential equation. During phase I, when some of the liquid is on the fabric surface, the area of the spreading liquid is proportional to the square root of time, in accord with the Washburn equation. Phase II is when the liquid is contained within the fabric. For impermeable fibers, the exponents are in agreement with previously reported values. When the liquid diffuses into the fibers, the exponents decrease, increase, or remain essentially constant. The exponent of the spreading of n-decane increases with increasing hydrophobicity of the fibers. The exponents of rayon fabric exhibit anomalies caused by the geometry of rayon fibers.

Novel oligomeric silanes having end-capped fluoroalkyl groups have been synthesized. The glass surface was modified by oligomeric as well as by monomeric silanes. From contact angle measurements, the surface free energies were determined and the surface was shown to be both highly water-and oil-repellent. Oligomeric-type silanes were more reactive and effective than monomeric-type silanes. A linear correlation was observed between the area ratio of the F 1s peak to the Si 2p peak. The structure of the siloxane layer is discussed in terms of a network interphase model.

Perfluoroalkanoyl peroxides such as (C3F7COO)2 have been found to react with polyester film only on the surface. The modified polyester surfaces were characterized by contact angle measurements using a two-liquid phase system and by ESCA spec troscopy. These provided surface free energy values and surface atom content values as a function of reaction time. Perfluoroalkyl groups substituted on the aromatic rings of the polyester surface influenced both the dispersive component γsd of surface free energy and the polar one γSp. The surface free energies decreased with the reaction time and reached a plateau at about 1 hour. There was a large decrease in γSd. Based on the ESCA characterization, the area ratio of the F1 s peak to the O 1 s peak was linearly correlated not only to γ Sd but also to γSp.