| In recent years, superhydrophobic fabrics has aroused more and more interestsdue to their outstanding characteristics like self-cleaning, anti-contamination,antibacterial, antisticking. So superhydrophobic fabrics are widely used in industry,agriculture, biomedical, etc. Various studies have been confirmed thatsuperhydrophobic surfaces are mainly produced in two ways：one is to create a roughstructure on surface, and the other is to modify a rough surface by compounds withlow surface free energy, like fluorocarbons or silicones. There are many approachesthat can be carried out to obtain surperhydrophoic surfaces. However, the presentmethods are quite complicated and not industrialized. Therefore, how to producehierarchical micro-and nano-structures simply and effectively becomes the researchfocus. Furthermore, fluorocarbons are harmful to environment and human health fortheir refractory. Meanwhile there are few reports about wool-polyester fabricssuperhydrophobic modification.In this study, wool-polyester fabrics and cotton fabrics were successfullyobtained by two finishing processes. Silica hydrosols with100nm and900nm wereprepared via the hydrolysis and condensation of Tetraethylorthosilicate(TEOS).Non-fluorinated hydrophobic cotton fabrics with silica particles could be obtained bydip-coating the silica hydrosols to obtain more excellent rough surface, and thenimmersing the hydrolyzed alkytrialkoxysilanes with different concentrations forsurface modification.In this experiment, silica hydrosols with different sizes and polydisperstiyindexes (PDI)were prepared by controlling the experiment conditions. The effects ofthe amount of ammonia, experiment temperature and different structures andconcentrations of the alkytrialkoxysilanes on the surperhydrophobic fabrics werediscussed in this paper. The wool-polyester fabrics and cotton fabrics were immersedin the silica hydrosols with100nm and hydrolyzed hexadecyltrimethoxysilane(HDTMS), and achieving superhydropobicity. The result showed that the water contact angle(WCA) of the treated cotton fabrics and wool-polyester fabrics were151.42±1.38°and138.4±4.72°, respectively. Unfortunately, the treatedwool-polyester fabrics weren’t surperhydrophobic surfaces.The method of silica hydrosols with900nm was discussed in this paper. Then thesuperhydrophobic fabrics were obtained by two steps coating. The fabrics weredipped-coated the silica hydrosols with900nm and100nm, successively. The WCAof two steps coated cotton fabrics and wool-polyester fabrics is157±1.8°and148±1.8°, respectively. The SiO2element and HDTMS were detected on the treatedfabrics by X-ray Photoelectron Spectroscopy(XPS). The surface morphology oftreated fabrics were characterized by scanning electron microscopy(SEM),field-emission scanning electron microscopy(FESEM) and atomic forcemicroscope(AFM). The results showed that the silica nano-particles had been coatedon the fabrics surface, resulting in a more effectively hierarchical micro-andnano-structures. In addition, physical properties of the treated fabric showed slightchange except the permeability, which could meet the application requirements. Bycomparing one-step coating, it was found that the superhydropobicity of the two-stepscoated fabrics were improved.Finally, in order to improve the superhydropobicity of wool-polyester, thewool-polyester fabrics are activated by oxidization and UV irradiation before thefabrics coated. The result showed that when the concentration of hydrogen peroxidewas5%wt.%and the100W UV irradiation was10minutes, the WCA of the treatedwool-polyester were150.1±1.13°.The surface morphology of treated fabrics werecharacterized by Allw rden reaction and SEM. The result showed that wool fibersexposed more sites in order to improve the coverage of the silica nanoparticles afteroxidization and UV irradiation, resulting in superhydropobicity. |
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