Study On UV Spectral Characteristics Of Alkylphenol Ethoxylate And Its Affinity Performance To Silk/Cotton

The Alkylphenol Ethoxylate (APEO) is a kind of important non-ionic surface active agents, which is widely applied in textile, leather and the daily life. In recent years, as its metabolic products has been proved very poisonous and can be concentrated in organism, it has draw people's wide concern for its prohibition on use. Silk is well known as the "fiber queen" and cotton is named as "King of fiber" According to the tested results, it's found that the APEO content in silk fabric is often far beyond the acceptable amount, while that in cotton fabric is relatively low. Though both of these two natural fibers contain polar groups, the APEO residues in the fabric differ greatly. As a result, it is very necessary to study their affinity to APEO.This paper takes APEO as the research object, trying to test the absorption of the APEO in the water with different textile materials under different conditions. Because the benzene rings in APEO connect with the auxochromic group O- directly, the characteristic ultraviolet absorption peak of the benzene ring is caused to obtain a red-shift. Based on this, APEO can be distinguished from other surface active agents containing the benzene, and the strong absorption around 224 nm and the weak absorption around 275 nm may be used for quantitative analysis to APEO. Moreover, the linearity range of the peak around 275 nm is quite wide; therefore the adsorption capability of the fabrics towards APEO can be got according to the standard working curve.With the adsorption capability as the index, the influence of the pH, solution temperature and the other factors on the fiber adsorption towards APEOs is tested and discussed. By the adsorption isotherms of the silk or cotton for the APEO, the adsorption model, dynamic model and related parameters were obtained. The adsorption model indicated the multilayer adsorption and fitted the Langmuir model. With the calculation of thermodynamics and proving of enthalpy, entropy and Gibbs free energy to be positive, the adsorption process is suggested to be driven by entropy. The adsorption dynamics indicate that the adsorption model of the silk towards APEO is pseudo second order model and the constant of adsorption rate is taken into Arrhenius equation, figuring out that the adsorption active energies of the silk towards APEO are far less than active energies needed for the chemical adsorption. Therefore, the adsorption of the silk towards APEO should be a physical adsorption.Comparative study showed that, the affinity of APEO to silk is much stronger than that to cotton, and the absorbable amount of APEO is also much higher than that on the cotton. The investigation indicated that the APEO is not easy to be washed cleanly if its adsorption on the silk, indicating much more important for the APEO prohibition on the silk. The TG analysis further proved that the selective OPEO has stronger affinity to silk than the NPEO. In addition, once the APEO is combined with the silk, stability of the silk may be increase.