关键词: 棉织物, 全氟癸基三甲氧基硅烷, 超疏水, 超疏油, 自清洁

Abstract: With the development of economics and the improvement of living standards, people have more and more requirements for the functionality of cotton fabrics. The preparation of superamphiphobic cotton fabrics with self-cleaning, UV irradiation stability, and antifouling has attracted extensive attention in recent years. Currently, superhydrophobic/superoleophobic cotton fabrics are commonly prepared by pre-constructing micro/nano-rough structures on the surface of cotton fabrics and then modified with low surface energy by fluorinated compounds. However, the preparation methods for superamphiphobic cotton fabrics mostly have the shortcomings for complex processes and relatively long term. Therefore, it is of great significance to explore simple and efficient processes for preparing durable superamphiphobic cotton fabrics.
Cotton fabrics were finished by impregnation method by using the hydrolyzed solution of perfluorodecyltrimethoxysilane(PFDMS), ammonia water, and anhydrous ethanol at the volume ratio of 1:50:50, 1:25:25, 3:50:50. The effects of the PFDMS concentrations and their hydrolyzed time on the surface amphiphobic of the fabrics were investigated. The surface morphology, elemental composition, wettability and mechanical stabilities, and chemical durability of the cotton fabrics were analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and contact angle tester, abrasion testing machine and UV aging tester. Meanwhile, the anti-fouling, and self-cleaning characteristics of the superamphiphobic cotton fabrics were tested and evaluated.
The results showed that the water/oil contact angle of PFDMS-coated cotton fabrics gradually increases with increasing concentration of the PFDMS solution. The cotton fabrics finished with the volume ratio of PFDMS to ammonia and anhydrous ethanol was 3:50:50 hydrolyzed for 10 min showed superamphiphobic with a water contact angle of 157.2°±0.3° and an oil contact angle of 150.0°±1.4°. SEM and EDX analyses showed that the surface of cotton fabrics finished with PFDMS has dense rough coatings, and two additional 0.66% of F and 3.37% Si elements were found on the surface. The XPS analysis showed obvious signal peaks of Si 2s, Si 2p and F1s, and −CF2 and −CF3 groups were found in the high-resolution of C 1s fit peaks. After 20 times of ultrasonic washing cycles (washing time was 600 min) for PFDMS-coated cotton fabrics, the water contact angle was 156.1°±1.3° and the oil contact angle was 147.7°±1.0°. After 10,000 times of abrasion for PFDMS-coated cotton fabrics, the water contact angle was 154.3°±0.9° and the oil contact angle was 138.4°±1.2°. After 24 h of UV aging, and 24 h of acid-base solution or organic solvent immersion, the contact angle of the surface of the superamphiphobic cotton fabric changed compared with that before the test, but the changes did not exceed 3.0°. The cotton fabric finished with PFDMS shows better self-cleaning properties and excellent anti-fouling to milk, coffee, orange juice, cola and soy sauce liquids. This process is efficient, the prepared cotton fabric has better mechanical stability and chemical durability. The prepared durable superamphiphobic cotton fabric has the potential applications in the field of anti-fouling and self-cleaning.

Key words: cotton fabric, perfluorodecyltrimethoxysilane, superhydrophobic, superoleophobic, self-cleaning