Promoting the utilization efficiency of agrochemicals via short-chain nonionic fluorinated synergist: Strategies and working mechanisms

Abstract

Wastage of agrochemicals results in considerable environmental pollution and economic loss. The use of trisiloxane surfactants as synergists has proven to allow for reduction in agrochemical application rates, but these surfactants show poor resistance to hydrolysis, which can attenuate their synergistic effects. Herein we report the development of a short-chain nonionic fluorinated surfactant, designated mPEG200-TEOH-6, as a novel agrochemical synergist. In contrast to conventional long-fluorocarbon chain surfactants, our short-chain fluorinated surfactant can avoid the risk of persistence and bioaccumulation in the environment. We determined the thermal storage stability of mPEG200-TEOH-6 and investigated its effects on the static surface tension, dynamic surface tension, contact angle, and thermal storage stability of four agrochemicals solutions, which explained its synergistic efficacy. In addition, we compared its effects with those of the commercial surfactant Silwet 408. Both mPEG200-TEOH-6 and Silwet 408 clearly improved the utilization efficiency of the agrochemicals, but mPEG200-TEOH-6 displayed substantially greater synergistic efficiency than Silwet 408; specifically, the former markedly decreased the static surface tension of agrochemical solutions, increased their diffusivity and wettability, and decreased their LC50 values. Strikingly, we found that mPEG200-TEOH-6 was more stable than Silwet 408 under thermal storage conditions. The result presented herein can be used to guide the use of surfactants and agrochemicals in agriculture.