Solvent-responsive surfaces prepared by various polymer brushes are described. The motivation and attractive feature of polymer brushes for the design of stimuli- responsive surface was also explained. Polymer brushes, in general, form a relatively stretched conformation in a good or theta solvent due to high osmotic pressure, but collapse in a poor solvent. Therefore, swollen thickness and morphology of brush can be changeable by a selective solvent. AB-type diblock copolymer brushes or binary mixed brushes treated with a selective solvent gave characteristic nano-patterned morphologies attributed to self-assemble behavior which induced large roughness on the surface to result in the wettability change. Swollen thickness and interfacial structures of polyelectrolyte brushes in aqueous solution are strongly affected with pH, added salt concentration, ion species, and temperature. pH-Responsive surface prepared by binary components mixed polyelectrolyte brushes was mentioned. Thermo-sensitive poly(N-isopropyl acrylamide) (PNiPAAm) brushes was used as a cell culture surface to achieve the smooth detachment of contiguous cell sheets under reduced temperature by using hydration behavior of PNiPAAm below lower critical solution temperature. Super hydrophilic poly(sulfobetine) brush was fabricated on super hydrophobic poly(vinylidene fluoride) (PVDF) membranes. The resulting membranes successfully separated oil and water from their dispersed mixture by filtration of water with suction and to remain oil portion on the membranes. This is a typical smart application of the characteristic oleophobic behavior underwater of poly(sulfobetine) brush. Various applications of super hydrophilic polyelectrolyte brushes can be expected in the future.
KeywordsPolymer brushes Surface-initiated polymerization Surface grafting Polyelectrolyte Selective solvent Antifouling
- Kudaibergenov S (2002) Polyampholytes. Kluwer Academic/Plenum Publishers, New York, pp 137–146Google Scholar
- Rühe J (2004) Polymer brushes on the way to tailor-made surfaces. In: Advincula RC, Brittain WJ, Caster KC, Rühe J (eds) Polymer brushes: synthesis, characterization, applications. Wiley VCH, Weinheim, pp 1–31Google Scholar