Preparation of an amphiphilic graft copolymer having poly(phthalazinone ether sulfone ketone)(PPESK) as main chains was carried out by atom transfer radical polymerization(ATRP).The precursor,chloromethylated PPESK (CMPPESK),was prepared by using chioromethylether as chloromethylation agent.Then,poly(ethylene glycol) methyl ether methacrylate(PEGMA) was used as monomer to synthesize PPESK-g-P(PEGMA) by ATRP method under the catalysis of a cuprous chloride/2,2'-bipyridyl system.PPESK/PPESK-g-P(PEGMA) blen... 相似文献
Green means go : A polyelectrolyte diode on a microchip exhibits well‐defined nonlinear rectifying behavior. This system visualizes the dynamic distribution of ions in a charged polymer phase under an electric field on a real‐time basis using fluorescence images (see picture). Multiple polyelectrolyte diodes are integrated on a microchip to produce a variety of logic gates based on ionic circuits.
The complexing ability of water-soluble calix[4]arene for l-tryptophan (l-try) was investigated by a variety of techniques. The spectrofluorometry titrations were performed at different temperatures to determine stability constants, as well as to evaluate the thermodynamic parameters of the obtained complex. The effect of pH on the complexation process was quantitatively assessed. Moreover, to obtain information about the binding mechanism of the interaction, 1H NMR studies were carried out. Molecular modeling showed that water-soluble calix[4]arene accommodated part of l-amino acid in its cavity meanwhile the aliphatic chain of l-tryptophan stuck out of the cavity. Based on the experiment data, the association process of complexes was established. The water-soluble calix[4]arene was found to be able to adjust its conformation to fit the size of aromatic l-tryptophan, and the benzene ring of amino acid penetrated into the hydrophobic cavity of calix[4]arene. 相似文献