Hypothesis The effective separation and recovery of oils from water is important for the protections of ecosystems and the environment. Polymeric porous monoliths have been demonstrated as attractive absorbents for oil/water separation. However, the recyclability was mainly realized by squeezing, combustion, or centrifugation, which may restrict in elastic materials, destroy the adsorbates or need special apparatus. Thus it is desirable to developing monoliths with controllable oil absorption and desorption. Experiments A series of “smart” monoliths with pH-induced switchable wettability were fabricated by high internal phase emulsion (HIPE) polymerization and epoxide ring-opening for the incorporation of amine groups. The resultant monoliths and their wettabilities were examined using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), nitrogen adsorption/desorption and contact angle analysis, respectively. The oil separation efficiency and recyclability were evaluated. Findings The monoliths with macroporous structure can undergo switchable wettability under reversible pH stimulation. As an absorbent, the monoliths not only separated and recovered organic solvents and oils (including crude oil) from aqueous mixtures through a reversible and recyclable absorption and desorption process upon alternating the pH between 7.0 and 1.0, but also continuously expulsed oils from water surfaces in a continuous manner with the aid of external driving pressures. Moreover, the monoliths also allowed the effective separation of surfactant-free and surfactant-stabilized oil-in-water emulsions with high separation efficiency.
Chao Yang,Jun Yang,Ge Song,Limin Zang,Qifan Liu,Jianhui Qiu,Xue Yang,Chun Wang
Oil/water separation has recently attracted a great deal of attention for research due to the frequent occurrence of an oil spill as well as the increase of industrial and household oily wastewater. Therefore, the purpose of this study is to demonstrate underwater superoleophobic crosslinked phosphorylated poly(vinyl alcohol) hydrogel coated stainless steel mesh (CL-PPVA@SSM), which was fabricated using a simple dip-coating method and aldol reaction on the mesh substrate. The as-prepared CL-PPVA@SSM is capable of separating oil from a variety of different oil/water mixtures with high separation efficiency up to 99.2%, excellent recyclability and fast water permeate flux of 467.7 L m –2 h –1 , which makes it suitable for the separation of oil-water mixtures from oil-water emulsions. Also, in the oil-water separation process, the CL-PPVA@SSM is capable to remove organic dye from the water. The CL-PPVA@SSM exhibits stability under various harsh conditions such as mechanical abrasion. Importantly, the CL-PPVA@SSM shows a massive potential to separate kitchen waste oil/water mixtures due to the underwater superoleophobic property as required for the recycling of kitchen waste oil. Therefore, this method has been met with a promising application prospect of practical application.
危险品化学品经营许可证（带存储）