Experimental and Numerical Modeling of the Controllable Wettability Gradient on Poly(propylene) Created by SF₆ Plasma

Abstract

A continuous and scalable wettability gradient of water contact angle (WCA) (20–135°) were successfully prepared on poly(propylene) film by applying O2 plasma for pretreatment followed by SF6 plasma treatment under a specially designed mask. Moreover, the role of mass transfer processes in the plasma treatment leading to the gradient formation was clearly described in mathematical terms. By mathematical analyses, a mass transfer coefficient calculated from the sample of 1 cm was employed for scaling‐up process to create gradients on sample length of 5 cm and 7 cm. ESCA analysis revealed that the incorporation of C–F bonds resulted in hydrophobicity on the surface and the formation of the gradient. The wide‐range wettability gradient was demonstrated as an effective tool for screening cell behaviors as demonstrated by culturing L‐929 fibroblast cells on the gradient.

Gradient biomaterials and their influences on cell migration

“…The slope of the resulting gradient could be conveniently tuned by changing the distance between the cover and the sample. Mangindaan et al [54] created a wettability gradient on a PP film by plasma treatment under a mask that had a 2 mm gap to the sample. Various functional groups such as amino groups, carboxyl groups, hydroxyl groups and sulphonic acid groups can be introduced onto the substrate by applying nitrogen, ammonia, oxygen and sulphur dioxide plasma, respectively [55,56].…”

Adsorption and precipitation of fluoride on calcite nanoparticles: A spectroscopic study

“…However, high resolution spectra from XPS, especially Ca2p spectra, C1s spectra, and F1s spectra are needed to reveal chemical bondings between each constituent. [18]. Carboxylic group (O@CAO) was found to be dominant that represented the original calcite molecules.…”

Effects of Oxygen Plasma and Dopamine Coating on Poly(Vinylidene Fluoride) Microfiltration Membrane for the Resistance to Protein Fouling

“…Commercially available hydrophobic PVDF membrane (Durapore, Millipore, GVHP14250), with nominal pore size of 0.22 μm, was modified by oxygen plasma which was performed in a plasma chamber equipped with 13.56-MHz radio frequency generator as described elsewhere [22]. O 2 plasma treatment was conducted at constant gas flow rate at 10 sccm under the total pressure of 100 mtorr.…”