Innovative Applications of Surface Wettability Measurements for Plasma‐Modified Three‐Dimensional Porous Polymeric Materials: A Review

Abstract

This review addresses state-of-the-art of wettability measurements for plasma-modified, three-dimensional (3D), porous, polymeric materials. Inherent challenges associated with evaluating wettability of these complex constructs are discussed, including expanding techniques from 2D to 3D substrates and collection of both static and dynamic contact angle (CA) data. Dynamic data include advancing and receding CA measurements, as well as changes in CA as a function of time. Limitations in analysis and interpretation of wettability data are highlighted to best represent wetting characteristics of plasma-treated porous materials, as is the importance of placing wettability data in context with simultaneous surface chemistry and roughness assessment. A list of best practices recommendations is provided.

Hydrophilic Modification of Polysulfone Ultrafiltration Membranes by Low Temperature Water Vapor Plasma Treatment to Enhance Performance

“…A 2 µL drop of ultrapure water was used. Treated membranes were hydrophilic in nature, therefore, measuring a static WCA was not possible . As an alternative, a video was collected at 25 frames per second for 10 s and θ was obtained for each frame by fitting the data using the Krüss onboard software (using circle fitting and identical probe liquid parameters including density = 0.9970 g/mL, viscosity = 0.0010 cP, and surface tension = 72.16 mN/m).…”

Flexible intramedullary nails for limb lengthening: a comprehensive comparative study of three nails types

“…The VDF-TeFE copolymer has high thermal stability in the oxidizing atmosphere and low free surface energy due to its chemical composition [34]. In addition, the developed porous surface of the composite coating prevents the water droplet from spreading [35,36].…”

Allylamine and Allyl Alcohol Plasma Copolymerization: Synthesis of Customizable Biologically‐Reactive Three‐Dimensional Scaffolds

“…For water contact angle (WCA) and X‐ray photoelectron spectroscopy (XPS) analyses, the polymer mixture was cast into a Teflon mold (20 × 3 mm 2 wells), which yielded larger scaffolds that allowed several analyses to be performed per sample. After CHCl 3 evaporation, porogen leaching was carried out in deionized (DI) water . Scaffolds were removed from the molds and placed in a petri dish to dry under ambient laboratory conditions before plasma treatment.…”

“…Static WCA measurements were collected on untreated scaffolds and plasma treated Si wafers. Plasma treatment rendered the porous scaffolds hydrophilic; thus, measuring a static contact angle was not possible . Video data taken at 25 frames per second over 10 s were therefore used to measure water absorption behavior of plasma‐treated scaffolds.…”

“…Water absorption rates were calculated by dividing drop volume by the time it took for the drop to be fully absorbed (determined from video analysis). For dynamic WCA measurements, time = 0 is defined as the time the water drop first comes into contact with the scaffold surface . The wettability (either static WCA or water absorption behavior) was evaluated for a minimum of three distinct locations on a minimum of at least three scaffolds ( n ≥ 9).…”