Example 1
Ethylene glycol (193 g, technical grade 98%, Applichem Darmstadt) is initially introduced into a round-bottomed flask and heated, and polyvinylpyrrolidone (4.5 g, Luvitec K90, BASF, Ludwigshafen) is introduced while hot. A solution of silver nitrate (4.5 g, 63.5% metal basis, Johnson Matthey, Enfield) in Ethylene glycol (20.5 g) and a solution of vanadium chloride (9 mg, 99%, Merck, Darmstadt) in Ethylene glycol (2.5 g) are then added and the mixture is heated to 120° C. The longitudinal growth of the nanowires is monitored under the microscope and after conclusion of the growth the reaction is stopped by pouring the hot reaction mixture into a water bath.
100 g of the crude mixture is centrifuged, the supernatant discarded. The precipitate is filled-up with water to 100 g and redispersed. Centrifugation, decanting and redispersing is repeated three times, after the last centrifugation less water is used for redispersion.