0000000000335401
AUTHOR
Sascha A. Pihan
Patterning of a Surface Immobilized ATRP Initiator with an Inkjet Printer
A new technique for patterning polymer brushes on the micrometer scale has been developed in which an inkjet printer was used to deposit droplets of acid on a surface-immobilized initiator for atom transfer radical polymerization (ATRP). The acid cleaved an ester bond in the ATRP initiator in a saponification reaction. As a result, the ATRP initiator was rendered inactive. To control the degree of defunctionalization, a new initiator containing a weak ester bond was derived from a tertiary alcohol. Comparison to an established ATRP initiator, derived from a primary alcohol, showed that the novel initiator was defunctionalized with a higher efficiency. Control of the reaction time allowed to…
V2O5 nanowires with an intrinsic iodination activity leading to the formation of self-assembled melanin-like biopolymers
V2O5 nanowires act as biomimetic catalysts resembling vanadium haloperoxidases (V-HPO). The nanowires display iodinating activity as confirmed by a colorimetric assay using thymol blue (TB), UV/Vis spectrophotometry and mass spectrometry (FD-MS). In the presence of dopamine these nanowires catalyze the fast and efficient synthesis of melanin-like biopolymers under mild conditions (aqueous solution, neutral pH and room temperature). The resulting melanin-like biopolymer obtained by the V2O5 nanowire catalysts was characterized by scanning electron microscopy (SEM), X-ray diffraction, UV-Vis, FT-IR and electric conductivity resembling the natural biopolymer both in its chemical and morphologi…