Microstructured Polymer Blend Surfaces Produced by Spraying Functional Copolymers and Their Blends

Abstract

We described the fabrication of functional and microstructured surfaces from polymer blends by spray deposition. This simple technique offers the possibility to simultaneously finely tune the microstructure as well as the surface chemical composition. Whereas at lower polymer concentration, randomly distributed surface micropatterns were observed, an increase of the concentration leads to significant changes on these structures. On the one hand, using pure homopolystyrene fiber-like structures were observed when the polymer concentration exceeded 30 mg/mL. Interestingly, the incorporation of 2,3,4,5,6-pentafluorostyrene changed the morphology, and, instead of fibers, micrometer size particles were identified at the surface. These fluorinated microparticles provide superhydrophobic properties leading to surfaces with contact angles above 165°. Equally, in addition to the microstructures provided by the spray deposition, the use of thermoresponsive polymers to fabricate interfaces with responsive properties is also described. Contact angle measurements revealed variations on the surface wettability upon heating when blends of polystyrene and polystyrene-b-poly(dimethylaminoethyl methacrylate) are employed. Finally, the use of spraying techniques to fabricate gradient surfaces is proposed. Maintaining a constant orientation, the surface topography and thus the contact angle varies gradually from the center to the edge of the film depending on the spray angle.

Synthesis, Characterization, and Bacterial Fouling-Resistance Properties of Polyethylene Glycol-Grafted Polyurethane Elastomers

“…More recently, research efforts have been focused on either the use of natural compounds with anti-biofilm properties [14][15][16][17], or on the development of intrinsically antimicrobial and antifouling materials, by either physical or chemical technological approaches [17][18][19][20]. Physical approaches mainly consist of developing micro-or nano-scale surface texturing in order to affect bacterial adhesiveness, growth, and more in general, biofilm formation [21][22][23][24]. Chemical approaches, instead, mainly involve the functionalization of material surfaces, to meet some criteria that are well-recognized to confer repelling activities, which include strong hydrophilicity, neutral charge, and the presence of groups that are able to establish hydrogen bonds [25].Polyethylene glycol (PEG) is undoubtedly, the most closely investigated antifouling polymer, as it meets all of the criteria listed above [26].…”

Highly Efficient Antibacterial Surfaces Based on Bacterial/Cell Size Selective Microporous Supports

“…The porous films selected for this study were prepared using polymer blends comprising a PS- b -PDMAEMA or PS- b -PDMAEMAQ block copolymers and high-molecular-weight polystyrene. The PS- b -PDMAEMA block copolymer employed was synthesized by atom transfer radical polymerization (ATRP) in two consecutive polymerization steps following previously reported procedures . ATRP allows, among others, a precise control over the chemical structure providing block copolymers with narrow polydispersities (PD: 1.2–1.3) as well as variable chemical composition.…”

“…The PS-b-PDMAEMA block copolymer employed was synthesized by atom transfer radical polymerization (ATRP) in two consecutive polymerization steps following previously reported procedures. 40 ATRP allows, among others, a precise control over the chemical structure providing block copolymers with narrow polydispersities (PD: 1.2−1.3) as well as variable chemical composition. For this study, the block Moreover, in a following step, the diblock copolymers (DBCs) were quaternized to provide quaternary ammonium salt groups.…”

“…Polystyrene macroinitiator (PS-Br) as well as the PS 42 - b -PDMAEMA 16 block copolymer was synthesized using previously reported procedures …”

“…Polystyrene macroinitiator (PS-Br) as well as the PS 42 -b-PDMAEMA 16 block copolymer was synthesized using previously reported procedures. 40 Quaternization of the PDMAEMA units in the block copolymers. In a round-bottom flask, 0.1 g (2.33 × 10 −4 mol of tertiary amine groups) of block copolymer PS 42 -b-PDMAEMA 16 was introduced and dissolved in 1.0 mL of THF under stirring at room temperature.…”