Super-hydrophobic membrane has received extensive attention from basic theories and practical applications. The properties of the super-hydrophobicity of membrane are strongly dependent on the prepared method, which is attracting increasing concerns worldwide. The properties of super-hydrophobic membrane are dominated by many factors including the chemical composition and the morphology of the surface. In this work, a simple method to fabricate super-hydrophobic membrane with weak hydrophilic polyethersulphone (PES) via a sol-gel process is reported. The weak hydrophilic PES membrane was used as a membrane-based, which was dipped into precursor Sol firstly. After heat treatment, the membrane was dipped into the fluoroalkylsilane solution and then dried by again a heat treatment. The super-hydrophobic and porous PES membrane was characterized by Fourier-Transform Infrared Spectrometers (FTIR), contact angle goniometer, atomic force microscope (AFM). The results showed that the contact angle of super-hydrophobic membrane was up to 154°treated by precursor sol for 20min and fluorinated for 20h. The hydrophobic functional groups on the membrane surface were fluorinated groups (-CF3, -CF2, and -CF) and -CH3. The AFM images results showed the membrane surfaces have micro-/nanometer crater-like protrusions. Those protrusions contributed for the rough surface of membrane, and the root mean square (rms) roughness was about 350.9nm. The hydrophobic groups and the surface roughness structure together lead to the super-hydrophobicity of the porous membrane.

Here a novel technique was employed to fabricated three-dimensionally porous polystyrene (PS) films via ultrasound assisted template method. In contrast to spin-coated thin film, different morphologies appeared on the films prepared by casting PS/toluene solution on glass substrates. By varying either systematic parameters or intrinsic parameters, surface structures changed from two-dimension flat pores to three-dimension sponge pores. The influences of ultrasonic intensity, frequency, irradiation time, film thickness and toluene content in water bath on surface morphologies were extensively studied. Scanning electron microscopy and white-light confocal microscopy showed that PS casted films with thickness of 200μm have a higher porosity and lower surface roughness within micrometer range. The contact angle measurement indicated slight changes of surface hydrophilicity with toluene content in water bath. Suitable toluene content favored multilayer formation of PS film and led to monodisperse pore distribution analyzed by ImageJ.

Here a simple method was developed to fabricate hydrophilic Polyethersulphone film via a sol-gel process. The correspondent hydrophilicity was evaluated by infrared spectral analysis, X-ray photoelectron spectroscopy, the contact angle measurement, atomic force microscope and scanning electron microscope analysis, respectively. Both FTIR and XPS analysis indicated that the film surfaces have a relatively dense sol layer, which favors to become hydrophilic. AFM analysis demonstrated that the higher hydrophilicity was mainly attributed to the surface roughness, while SEM images show that the micro/nanometer crater-like protrusions appears on the film surfaces, whereas the spongy structures & the finger-like structures appear in cortex and intermediate layer respectively. This leads to the hydrophilic film forming after film being treated by sol-gel method.

Here a simple method was developed to fabricate super-hydrophobic membrane with hydrophilic Polyethersulphone (PES) via a sol-gel process. The influences of experimental parameters i.e. the precursor treated time, the baking temperature of the membrane, and the fluorinated time on the hydrophobicity of the membranes were extensively investigated. The correspondent hydrophobicity was crosschecked by the contact angle measurement. For the optimum condition, the contact angle of the resulted super-hydrophobic membrane can be increased to 156°. The FTIR analysis confirmed that the membrane surfaces were covered by hydrophobic functional groups, which resulted in both higher surface roughness and higher heterogeneity, and therefore higher hydrophobicity. The micro/nano-meter crater-like protrusions on the membrane surfaces were observed from the images obtained from both AFM and SEM measurements. Moreover, the spongy holes and the finger-like holes were observed in cortex and intermediate layer respectively, from the cross-section of the SEM images.

In this study, porous polystyrene membranes were prepared by a template-leaching technique. A suspension was first prepared by dispersing both polystyrene and starch in toluene, in which starch was used as leachable component. The weight ratio of starch/polystyrene ranged from 1:1, 1:2 to 1:3, whereas the concentration of the suspensions altered from 1%, 3%, to 5% by weight of polystyrene/toluene. After spin-coating the prepared suspension on the glass substrate, polystyrene/starch thin-film was produced, and then was treated with inorganic acid to remove starch components. The porous films with ordered and homogeneous structures were resulted. Analysis by contact angle measurement, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy analysis (FTIR) show that the microstructures on the porous films were affected by many experimental factors during the formation of thin-film and the following leaching process. Especially the type of the inorganic acid such as HCl, H2SO4, or HNO3, and the concentration of the specific acid selected in the leaching process have dramatic influences on the formation of the porous polystyrene membrane. The results further demonstrated that starch particles can be maximally removed when the films were immersed into the aqueous solution of HNO3.