Reduction in Insect Attachment Caused by Different Nanomaterials Used as Particle Films (Kaolin, Zeolite, Calcium Carbonate)

In the present investigation, we compared the reduction in attachment ability of the southern green stinkbug Nezara viridula (Hemiptera: Pentatomidae) to glass induced by three different nanoparticle (kaolin, zeolite, and calcium carbonate) films. Using traction force experiments, behavioral experiments, and scanning electron microscopy observations, we analyzed the insect attachment ability and linear speed on untreated and treated glass with the three particle films. The three nanomaterials strongly reduced insect attachment ability mainly owing to contamination of attachment pads. The ability to reduce insect attachment was different for the three tested particle films: kaolin and zeolite induced a significantly higher reduction in N. viridula safety factor than calcium carbonate. The coating of the surface was more uniform and compact in kaolin and zeolite compared to calcium carbonate particle film. Moreover, kaolin and zeolite particles can more readily adhere to N. viridula attachment devices, whereas calcium carbonate particles appeared less adherent to the cuticular surface compared to the two aluminosilicate (kaolin and zeolite) particles. Only the application of kaolin reduced insect linear speed during locomotion. Nanoparticle films have a great potential to reduce insect attachment ability and represent a good alternative to the use of insecticides for the control of pentatomid bugs and other pest insects.

Optimization of the microstructure of carbonized lime mud by sodium polyacrylate

Lime mud (LM) is a by-product originated from the causticization process of papermaking industry. Microscopic structural changes of LM in carbonization process lead to defects on its performance. Regulating the growth of calcium carbonate obtained from the carbonization process and preventing its influence on the surface microstructure of LM has become the key to achieve the self-digestion of this solid waste. In this study, microscopic structural changes of LM co-carbonized with sodium polyacrylate (PAAS) were investigated. The results showed that, compared with traditional carbonation, the microstructure of LM co-carbonized with PAAS was changed remarkably. The newly calcium carbonate formed in the carbonization process would be solidified and coated on the LM surface. Then LM co-carbonized with PAAS would have a smaller specific surface area, pore volume and pore size, which significantly improved its application performance when it was used as paper filler. In addition, a potential technique for improving the surface microstructure of calcium carbonate particle was proposed.