Conjugated Polyimidazole Nanoparticles as Biodegradable Electrode Materials for Organic Batteries

Conjugated polymers are promising active materials for batteries. Batteries not only need to have high energy density but should also combine safe handling with recyclability or biodegradability after reaching their end-of-life. Here, π-conjugated polyimidazole particles are developed, which are prepared using atom economic direct arylation adapted to a dispersion polymerization protocol. The synthesis yields polyimidazole nanoparticles of tunable size and narrow dispersity. In addition, the degree of crosslinking of the polymer particles can be controlled. It is demonstrated that the polyimidazole nanoparticles can be processed together with carbon black and biodegradable carboxymethyl cellulose binder as an active material for organic battery electrodes. Electrochemical characterization shows that a higher degree of crosslinking significantly improves the electrochemical performance and leads to clearer oxidation and reduction signals of the polymer. Polyimidazole as part of the composite electrode shows complete degradation by exposure to composting bacteria over the course of 72 h

Differences in absconding between African and European honeybee subspecies facilitate invasion success of small hive beetles

Small hive beetle (SHB) is an invasive species in populations of European honeybee subspecies, but underlying reasons for SHB success are not well understood. African and European honeybee, Apis mellifera, subspecies differ in absconding, and small hive beetle, greater wax moth (GWM) and ants all can exploit abandoned nests. However, the impact of host absconding on SHB reproduction and the role of GWM and ants as competitors are not known. Here, we conducted a survey in South Africa, Australia and the USA to evaluate SHB and GWM reproduction and foraging by ants in abandoned honeybee colonies. While the impact of competing ants and GWM was not significant, the data show higher SHB reproduction in abandoned nests of European honeybees compared to African ones, but less for GWM. The positive correlation between abandoned protein sources (brood, pollen) on SHB reproduction suggests that the less efficient preparation for absconding by European honeybee subspecies combined with their large colony sizes is a key factor for the invasion success of SHB