Silicon substrates were coated with well‐defined glycidyl and alkyne groups containing terpolymer that was synthesized by NMRP. The polymer was successfully tethered on silicon wafers and the resulting solvent stable, homogeneous, smooth thin films were characterized by means of atomic force microscopy (AFM), spectroscopic ellipsometry in the visible (Vis), and infrared (IR) spectral range. Subsequently, the films were modified in a heterogeneous reaction, converting the alkyne groups of the surface efficiently and quantitatively with azides by click chemistry. Appropriate film analysis allowed to directly verify the reaction of the alkyne groups with the azides and revealed that the chemical and physical properties of the thin films have changed while their morphology and topography is preserved.magnified image
Hydrophilic poly(ethylene glycol)-based monoliths were synthesized in the spin-tip format for high-throughput applications via pulsed electron beam irradiation. Monoliths with a homogeneous porous structure and a total porosity of 69% were obtained. The cross-linked polymeric structure was further mechanically stabilized via the incorporation of silica nanoparticles. Amino-functionalization of the monoliths was accomplished by a straightforward, water-based, one-step approach that entailed the electron-beam irradiation-induced grafting of poly(allylamine). The amine functionalized spin columns showed very low unspecific protein adsorption and were successfully applied as adsorbents in lectin affinity chromatography for the purification of ovalbumin. The novel columns also outperformed a commercially available system.
In this study we publish a novel attempt to macroporous, polymeric cryogels (MPCs) by electron-beam (EB) initiated free radical crosslinking polymerization of (meth)acrylates in frozen aqueous media. The EBprocess is an environmentally benign fast process (radiation and reaction time about 10-20 min) which allows the initiator-free polymerization of double-bond containing monomers. The MPCs were thoroughly characterized by swelling experiments, SEM, detailed XPS studies, DMA, Hg intrusion porosity and ESEM. The processes during the reaction were studied using ESR experiments. The influences of the reaction parameters like dose, radiation time, freezing conditions, chemical composition and (meth)acrylate concentration on the properties of the MPCs were investigated. The MPCs were synthesized in situ in capillaries or in tubes up to a diameter of 25 mm. The porous structure of the MPCs is mainly controlled by the freezing temperature and the macromonomer/crosslinker concentration and consists of large interconnected pores in the range of 10-70 mm. The crosslinker concentration directly affects the stiffness and the T g of the materials. The MPCs were successfully modified with poly(allylamine hydrochloride). This straightforward method provides a toolbox for the synthesis of manifold MPCs from various unsaturated substances in large quantities and scale.
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