Research On Preparation And Properties Of Functionalized Surfaces For Oil-Water Separation

Functionalized surfaces refer to those materials which possess one or more specific functions. The inspiration for the preparation of these functionalized surfaces often comes from the functionally structured surfaces of livings, such as the self-cleaning surface of the lotus leaves. More importantly, researchers further develop a broad spectrum of important applications, including corrosion resistance, anti-fogging, anti-icing, drag reduction, oil-water separation, anti-fouling and enhanced floatability etc.The leakage of oil from industrial accidents or crude oil transportation occurs frequently, which has caused severe catastrophes to ecosystems. To tackle these deteriorating problems, numerous strategies have been proposed to design novel surfaces or devices for oil-water separation. Therefore, to further broaden the practical application of functionalized surfaces in the field of oil-water separation, in this thesis, we promote the facile combination of functionalized surfaces and a speed-regulating peristaltic pump (BT300-2J) with the introduction of functional collaboration theory into the system, resulting in a new generation of superhydrophobic functionalized devices for oil-water separation.Non-magnetic copper foams and magnetic nickel foams are applied for the rapid electroless metal deposition to create enough roughness, followed by the monolayered modification of thiol molecules. The as-prepared surfaces will have a WCA of 151.1±0.5° and an OCA of about 0°. Under the control of the magnetic field, a device following a simple assembly process of the as-prepared surfaces can separate and collect oil spills located on different sites of oi-water mixtures continuously and efficiently. Adjusting the pumping speed from 30 rpm to 40 rpm,50 rpm,60 rpm,70 rpm and 80 rpm, the oil collector will maintain no water collected. Experimental data demonstrate that the mean oil-water separation efficiency is as high as 95%. In order to investigate the efficient collection mechanism, we have proposed the air switch concept for the first time. Namely, the-1 mm thick air layer between pump pipe and the bottom of the as-prepared device serves as a self-adaptive oil collecting switch to achieve a continuous "ON-OFF-ON" program. Besides, the as-prepared device can be reused more than 10 times for one kind of oil or for more than two different kinds of oils, which well meets the need of the development of eco-friendly, low-cost and smart materials.