Superhydrophobic–superoleophilic electrospun nanofibrous membrane modified by the chemical vapor deposition of dimethyl dichlorosilane for efficient oil–water separation Faride Zareei Pour, 1 Mohammad Mehdi Sabzehmeidani, 1 Hajir Karimi , 1 Vahid Madadi Avargani, 1 Mehrorang Ghaedi 2 1 Chemical Engineering Department, Yasouj University, Yasouj, 75918-74831, Iran 2 Chemistry Department, Yasouj University, Yasouj, 75918-74831, Iran Correspondence to: H. Karimi (E-mail: hakar@yu.ac.ir) ABSTRACT: Superhydrophobic and superoleophilic functionalized electrospun poly(vinylidene fluoride) (PVDF) membranes with water repellence, breathability, and oil-sorption and oil–water separation properties were achieved with a combination of an electrospinning technique and the chemical vapor deposition of dichlorodimethyl silane. The samples were laterally characterized by scanning electron microscopy, atomic force microscopy, water contact angle measurement, and Fourier transform infrared spectroscopy. The maximum water contact angle value was 152.0  2.5  for the PVDF nanofibrous membranes with 500 μL of deposited silane (PMS2) obtained under certain conditions. The PMS2 membranes showed 100.0, 93.7, 23.3, 35.0, and 100.0% separation efficiencies for n-hexane, kero- sene, crude oil, frying oil, and toluene, respectively. The understudy membrane exhibited reasonable waterproofness and remarkable breathability (water vapor transition rate = 215.21 g/m 2 .h). Moreover, the superhydrophobic and superoleophilic nanofibrous mem- branes also showed good reusability, stability, moderate water-repellent properties, breathability, antifouling properties, and oil–water separation ability after several cycles. These properties confirmed potential in feasible applications, including protective cloths and in the purification of oil-polluted water. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47621. KEYWORDS: coatings; fibers; membranes; separation techniques Received 25 September 2018; accepted 14 January 2019 DOI: 10.1002/app.47621 INTRODUCTION Oil spills and contamination in water are major problems because of the difficulties of the treatment procedure; this has encouraged researchers to construct and design efficient ways to remove oil con- tamination from water before it is discharged into the environ- ment. 1,2 Accordingly various strategies have been applied to reduce the harmful effects of oily wastewater on human health. 3,4 There are many surfaces in nature that have superhydrophobic properties and water contact angles above 150  . 5,6 Recently, various technologies have focused on the fabrication of such surfaces in the oil absorp- tion and separation field to supply selective performances when in contact with oil and water through different methods. The major properties of oil absorbents include hydrophobicity, sorption capac- ity, flow rate, buoyancy, durability, and reusability. 7,8 Superhydrophobic and superoleophilic filters applied in different shapes and structures, such as films, 9 meshes, 10 and membranes, 11 allow oil to pass through them but refuse water movement. Tradi- tional technologies, including oil skimming, air flotation, gravity separation, flocculation, and coagulation, are good choices for treat- ing oil–water contaminants but fail in the purification of some oil– water mixtures. Among these technologies, including the mechani- cal, chemical, and biological treatment of oily wastewater, 12–16 more attention and advantages are achieved after membrane separation, which has a greater ability to remove oil, with its low energy cost and tightly packed design compared with other treatment methods. 17,18 The high hydrophobicity and oleophilicity of these types of membranes help increase oil separation, sorption capacity, recoverability, and availability. 19 Oil–water separation and oil absor- bents include inorganic mineral, organic natural, and synthetic organic products such as some polymeric fibers. 20–22 Oil absorbents such as polymeric membranes have attracted significant research attention because of their practical applications in the separation of oil from water, self-cleaning, antifouling, and protective clothing. 23,24 Electrospinning applications in areas such as filtration, 25,26 photocatalysis, 27 drug delivery, 28 adsorption, 29 tissue scaffolds, 30 and protective textiles 31 have been studied. 32 The ease of the electrospin- ning technology, the variety of electrospinnable substances, and the Additional Supporting Information may be found in the online version of this article. © 2019 Wiley Periodicals, Inc. 47621 (1 of 11) J. APPL. POLYM. SCI. 2019, DOI: 10.1002/APP.47621