A Facile Method for Preparing Sticky, Hydrophobic Polymer Surfaces

Abstract

Textured surfaces consisting of nanometer- to micrometer-sized lightly sulfonated polystyrene ionomer (SPS) particles were prepared by rapid evaporation of the solvent from a dilute polymer solution-cast onto silica. The particle textured ionomer surfaces were prepared by either spin-coating or solution-casting ionomer solutions at controlled evaporation rates. The effects of the solvent used to spin-coat the film, the molecular weight of the ionomer, and the rate of solvent evaporation on the surface morphology of cast films were investigated. The surface morphologies were consistent with a spinodal decomposition mechanism, where the surface first existed as a percolated-like structure and then ripened into droplets if molecular mobility was retained for sufficient time. The SPS particles or particle aggregates were robust and resisted separation from the surface even after annealing at 120 °C for 1 week. The water contact angles on as-prepared surfaces were relatively low, ∼90°, due to the polar groups in the ionomer, but when the surface was modified by chemical vapor deposition of 1H,1H,2H,2H-perfluorooctyltrichlorosilane, the surface contact angles increased to ∼109° on smooth surfaces and up to ∼140° on the textured surfaces. Although the surfaces were hydrophobic, the contact angle hysteresis was relatively high and water droplets stuck to these surfaces even when the surface was turned upside down.

Highly sticky surfaces made by electrospun polymer nanofibers

“…The mats on glass and the free-standing carpets of nanofibers present Vmax ~45 μL or higher and Vmax ~40 μL, respectively, which corresponds to a spherical drop having a diameter of about 4.5 mm, almost twice the characteristic volumes obtained with hairy surfaces prepared in different ways. 8,16,17,19,[43][44][45][46] The sticky behavior of these superhydrophobic surfaces is well-explained in terms of the Cassie impregnating state. The slightly lower Vmax value for free-standing samples might be related to minor topological differences in the electrospun fibers, which is reliable given the observed scatter in the data corresponding to samples prepared in the same nominal conditions.…”

“…8 Key features to achieve a specific superhydrophobic behavior involve both a proper chemical composition of the surface and an appropriate roughness at the micro/nanometer scale, 2, 9, 10 since in untextured surfaces θ is generally below 120°, which is the value characteristic of fluorinated materials. 1 Various physical and chemical methods have been employed to realize either self-cleaning [11][12][13][14][15] or sticky 8,[16][17][18][19] superhydrophobic surfaces. In this framework, electrospinning provides a simple and practical way to tailor surface roughness over large areas through coatings made of fibers with diameters ranging from tens of m to tens of nm, which are produced from polymer solutions with sufficient molecular entanglements.…”

Synthesis and Characterization of Polystyrene-Supported Piperazine-Substituted Triazoles by CuAAC and First Evaluation for Metal Ion Extraction

“…For a long time, what we call ion exchange resins, polymers bearing groups chelating a non-toxic metal cation such as sodium or others that can be exchanged with the cation for removal, have been used [1,2,3]. Several polymers can be made, and substitutions introduced, in order to create hydrophilic [4,5,6,7] and hydrophobic polymers [8,9], in order to use them in different applications [10,11,12,13,14]. Ideally, a polymer that can be easily functionalized for a specific application is of great interest.…”

“High-Throughput” Evaluation of Polymer-Supported Triazolic Appendages for Metallic Cations Extraction

“…The long time known ion-exchange resins can be used for this purpose [1][2][3]. Usually, the polymers are engineered is such a way that their nature can be hydrophilic [4][5][6][7] or phobic [8,9], to meet the requirements for their use [10][11][12][13][14]. Many polymers have been designed in order to include chelatants to fix metal ions to be used in applications such as purification, depollution or catalysis [15][16][17][18][19][20].…”