Yang Rong, Goktekin Esma, Gleason Karen K
Department of Chemical Engineering, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
Department of Chemical Engineering, Northeastern University , Boston, Massachusetts 02115, United States.
Langmuir. 2015 Nov 3;31(43):11895-903. doi: 10.1021/acs.langmuir.5b02795. Epub 2015 Oct 21.
Fouling refers to the undesirable attachment of organic molecules and microorganisms to submerged surfaces. It is an obstacle to the purification of shale gas produced water and is currently without an effective solution due to the highly contaminated nature of produced water. Here, we demonstrate the direct vapor application of a robust zwitterionic coating to a variety of substrates. The coating remains unprecedentedly hydrophilic, smooth, and effectively antifouling in extremely high salinity solutions (with salt concentration of 200,000 ppm). The fouling resistance is assessed rapidly and quantitatively with a molecular force spectroscopy-based method and corroborated using quartz crystal microbalance system with dissipation monitoring. Grazing angle attenuated total reflectance Fourier transform infrared is used in combination with X-ray photoelectron spectroscopy, atomic force microscope, and in situ spectroscopic ellipsometry to lend insight into the underlying mechanism for the exceptional stability and effectiveness of the zwitterionic coating under high-salinity conditions. A unique coating architecture, where the surface is concentrated with mobile zwitterionic moieties while the bulk is cross-linked to enhance coating durability, was discovered to be the origin of its stable fouling resistance under high salinity. Combined with previously reported exceptional stability in highly oxidative environments and strong fouling resistance to oil and grease, the zwitterionic surface here has the potential to enable low-cost, membrane-based techniques for the purification of produced water and to eventually balance the favorable economics and the concerning environmental impacts of the hydraulic fracturing industry.
污垢是指有机分子和微生物在浸没表面上的不良附着。它是页岩气采出水净化的障碍，由于采出水的高污染性质，目前尚无有效的解决方案。在此，我们展示了一种坚固的两性离子涂层在各种基材上的直接气相应用。该涂层在极高盐度溶液（盐浓度为200,000 ppm）中仍保持前所未有的亲水性、光滑性且具有有效的防污性能。采用基于分子力谱的方法对其抗污性能进行了快速定量评估，并使用带有耗散监测的石英晶体微天平系统进行了验证。掠角衰减全反射傅里叶变换红外光谱与X射线光电子能谱、原子力显微镜和原位光谱椭偏仪结合使用，以深入了解两性离子涂层在高盐度条件下具有卓越稳定性和有效性的潜在机制。发现一种独特的涂层结构，即表面富含可移动的两性离子部分，而主体部分交联以增强涂层耐久性，是其在高盐度下具有稳定抗污性的根源。结合先前报道的在高氧化环境中的卓越稳定性以及对油脂的强抗污性，这里的两性离子表面有潜力实现基于膜的低成本采出水净化技术，并最终平衡水力压裂行业良好的经济效益和令人担忧的环境影响。
