Halloysite nanotubes as nanocarriers for plant herbicide and its controlled release in biodegradable polymers composite film

The active ingredients of eupatorium adenophora spreng (AIEAS) as botanical herbicide were first loaded in halloysite nanotubes (HNTs) with the amount of 7.26 wt%, and then the AIEAS-loaded HNTs (HNTs-AIEAS) were further incorporated into poly(vinyl alcohol)/starch composites (PVA/ST, with the weight ratio of 80/20) to prepare a dual delivery system for AIEAS. The AIEAS loaded in HNTs showed much slower release from PVT/ST film through soil layer than free AIEAS. For example, after ten times of leaching in water, the total release amount of AIEAS from PVA/ST film with HNTs-AIEAS was only 31.7%, while this value reached 61.3% in PVA/ST film with free AIEAS. Moreover, HNTs-AIEAS could significantly improve the erosion resistance of PVA/ST film, which only reinforced the film skeleton, thus delaying the release of herbicide, but also significantly prolonged the service life of PVA/ST/HNTs-AIEAS composites film as biodegradable agricultural mulch film.