Effective Oil/Water Separation Sorbent Based on Nylon 6,6-Organoclay Nanofiber Mats

Abstract

Oil spills and marine pollution caused by oil spills have a serious effect on environment and human life. The efficient removal of oils, petroleum-based products, and organic solvents from water is important for protecting the environment. Oil-absorbent nanofiber mats with high oleophilicity were prepared by electrospinning in the present work. Nylon 6,6 is chosen as a crystalline polymer with oleophilic hydrocarbon chains that are linked by hydrophilic functional amides. There has been little research into using electrospun Nylon 6,6 as an oil absorbent to remove oil from water. Two different organically modified montmorillonites (o-MMT, with trade names Tixogel VP and Cloisite 20A—C20A) are separately incorporated into Nylon 6,6 polymer to produce nanofiber mats with more oleophilic properties. To achieve efficient dispersion and exfoliation of organoclays in Nylon 6,6/formic acid solution, ultrasonication is applied for 30 min, followed by mixing for 24 h with a magnetic stirrer. After reaching a more homogenous solution, Nylon 6,6-organoclay nanofiber mats were then successfully electrospun by the electrospinning technique and characterized by using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA), and water contact angle measurement (WCA). The mechanical properties of the mats were also evaluated. The absorption behavior of the mats for motor oil and other domestic oils was investigated and the absorption capacity calculated in terms of weight gain. Differences in the absorption capacity of these three types of oil were found to be due to the surface tension of the solvents in the oil and viscosity. It has been found that the nanofibers produced have a very high oil absorption capacity in the case of a 2% loading of organoclay. These newly produced mats demonstrated excellent motor oil absorption of 60–80 times their own weight in motor oil. It can be concluded that these novel oil-absorbing materials are promising candidates for the treatment of wastewater containing oil.