Surface Wettability Characterization Of Synthetic Fibers By Inverse Gas Chromatography

The key to oil- water separation by the method of coalescence is to choose appropriate coalescing element. It is well knows that the surface wettability of coalescing element determines the tendency of oil or water liquid to attach to the surface of the coalescing element. For the current research, the surface wettability is mostyly judgd on the basis of the surface energy. However, the common methods for the determination of the surface energy usually are not suitable to the fiber coalescing element. This paper attempts to apply the method of inverse gas chromatography to the surface wettability characterization of the coalescing element.This paper chosed polypropylene fiber, polyhexamethylene sebacamide fiber and polyethylene terephthalate fiber as the research object. When n-alkanes were used as probes, the dispersive component of Gibbs surface free energy of synthetic fibers at different temperatures was determined. When esters were used as probes, the adsorption enthalpy was determined. When water was used as probes, the net retention volume of water in chromatography column was measured and the adsorption enthalpy of water on polyhexamethylene sebacamide fiber and polyethylene terephthalate fiber was calculated. With the above parameters as the basis of judgment, the surface wettability of synthetic fibers can be characterized. Then the influence factors such as temperature, the chemical structure unit of fiber, the yarn structure and the number of carbon atoms of probes were also discussed.The results show that the chemical structure unit of the synthetic fiber is the decisive factor of the surface wettability. N-alkanes have a good affinity with the surface of polypropylene fiber, while esters and water have a good affinity with the surface of polyhexamethylene sebacamide fiber and polyethylene terephthalate fiber. The yarn structure affects the expansion level directly when fiber is heated, which has a great effect on temperature dependence of the dispersive component of surface free energy, the adsorption enthalpy of esters on the surface of synthetic fibers and the net retention volumn of water. The number of carbon atoms of probes affects the change trend of the adsorption enthalpy of probes on the surface of synthetic fibers. In general, the method of inverse gas chromatography is simple, fast and only needs a small amount of sample and reagent. This method overcomes the shortcomings of existing methods of measurement and is able to determine the surface wettability of the fiber coalescing element effectively.