RESUMEN
A simple and efficient polymer grafting onto hydrothermal carbonization (HTC)-derived materials is described. The method pertains to the Diels-Alder cycloaddition reaction of furan moieties present on the surface of a HTC material with the maleimide groups stemming from a maleimide protected poly(ethylene glycol) (Me-PEG-MI) by a retro Diels-Alder reaction. The precursor polymer, HTC material, and final product are characterized. Successful grafting is confirmed by elemental analysis, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and dispersion studies.
Asunto(s)
Carbono/química , Polietilenglicoles/química , Reacción de Cicloadición , Furanos/química , Calor , Maleimidas/química , Espectroscopía de Fotoelectrones , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
π-Conjugated microporous networks have been prepared from the tetraarylated diketopyrrolo[3,4-c]pyrrole unit as a tetrafunctional building block. The reactions are carried out using microwave-assisted Yamamoto or Sonogashira cross-coupling. Red insoluble powders are obtained, showing intense fluorescence. The polymer networks exhibit a high gas storage capability, with BET surface areas up to about 500 m(2)·g(-1).
Asunto(s)
Polimerizacion , Polímeros/química , Pirroles/química , Adsorción , Catálisis , Color , Luminiscencia , Espectroscopía de Resonancia Magnética , Microondas , Estructura Molecular , Níquel/química , Nitrógeno/química , Paladio/química , Polímeros/síntesis química , Porosidad , Solubilidad , Propiedades de SuperficieRESUMEN
In a metal-free procedure, chelating thiol groups and an electrophile react to assemble a robust, conjugated porous polymer with pendant aldehyde functionalities. These groups are able to reduce Ag(i) ions to generate, in situ, Ag(0) nanoparticles evenly dispersed in the polymer matrix. The Ag(0)-polymer composite enables selective reduction of aromatic nitro compounds as a heterogeneous catalyst, and can be conveniently recycled multiple times.
Asunto(s)
Aldehídos/química , Hidrocarburos Aromáticos/química , Nanopartículas del Metal/química , Nitrocompuestos/química , Polímeros/química , Plata/química , Estructura Molecular , Oxidación-Reducción , Tamaño de la Partícula , Porosidad , Propiedades de Superficie , TemperaturaRESUMEN
Hyperphosphorylation at tyrosine is commonly observed in tumor proteomes and, hence, specific phosphoproteins or phosphopeptides could serve as markers useful for cancer diagnostics and therapeutics. The analysis of such targets is, however, a challenging task, because of their commonly low abundance and the lack of robust and effective preconcentration techniques. As a robust alternative to the commonly used immunoaffinity techniques that rely on phosphotyrosine(pTyr)-specific antibodies, we have developed an epitope-imprinting strategy that leads to a synthetic pTyr-selective imprinted polymer receptor. The binding site incorporates two monourea ligands placed by preorganization around a pTyr dianion template. The tight binding site displayed good binding affinities for the pTyr template, in the range of that observed for corresponding antibodies, and a clear preference for pTyr over phosphoserine (pSer). In further analogy to the antibodies, the imprinted polymer was capable of capturing short tyrosine phosphorylated peptides in the presence of an excess of their non-phosphorylated counterparts or peptides phosphorylated at serine.