Humics‐based interpolyelectrolyte complexes for antierosion protection of soil: Model investigation

Abstract

The aim of this article is to demonstrate a novel polymer‐based technique for stabilization of soil against wind and water erosion. Conventional approaches deal with individual water‐soluble polymers, which, being deposited on the soil, are removed from the soil surface after rewatering. Here, we describe an elegant way for soil stabilization via deposition of interpolyelectrolyte complexes formed by two oppositely charged water‐soluble polymers. Electrostatic complexation in an aqueous solution of a cationic poly(diallyldimethylammonium chloride) with an excess of water‐soluble anionic biopolymers, humic acids, results in formation of a negative non‐stoichiometric interpolyelectrolyte complex (NIPEC). Upon deposition of a NIPEC aqueous solution over soil and drying out, a protective layer (crust) forms on the surface, composed of NIPEC and soil particles, resistant to wind and water erosion. After destruction, the crust is completely restored by rewatering. The high stability of the NIPEC‐soil crust is due to a NIPEC block structure with hydrophilic free anionic units and hydrophobic mutually neutralized anionic/cationic units, which ensures optimum adsorption on the surface of soil particles and binds them to bigger aggregates. The NIPEC treatment retains the porous structure of soil that favors seed germination and plant development. Being effective absorbent of heavy metals, the NIPEC formulation ensures a normal seed germination in the presence of toxic Cu2+ ions. Thus, the humics‐based NIPECs ensures antierosion protection and detoxification of soil. Additionally to ecological and agricultural applications, the NIPEC formulations have potential for immobilization of moving sands, conservation of mining dumps, treatment of road slopes, and so forth.

A Dramatic Change in Rheological Behavior of a Clay Material Caused by a Minor Addition of Hydrophilic and Amphiphilic Polyelectrolytes

“…As for the anionic PHum, their macromolecules were shown to form colloid particles with the several dozens of nanometers in diameter when dispersed in a water medium [25,26]. For this reason, PHum is likely covered only a part of the kaolinite surface.…”

Interpolyelectrolyte complexes as effective structure‐forming agents for Chernozem soil

“…It has been shown previously (Panova et al, 2020;Panova, Drobyazko, et al, ), that, in neutral aqueous solutions, anionic PH elec- (Bezuglova & Yudina, 2006;Gajic, Dugalic, & Djurovic, 2006)…”

“…The total sample ('re-constructed Chernozem') was put into a cylindrical container filled with water for 10 min and then weight. This approach was used earlier in our work (Panova et al, 2020;Panova, Drobyazko, et al, 2019) and followed the conditions of water treatment described in Sepaskhah and Bazrafshan-Jahromi (2006).…”

“…In the previous papers (Panova et al, 2017;2019, 2020Panova, Drobyazko, et al, 2019) we described the use of IPECs for stabilization of several types of soils/grounds with different contents of organic matter. It was shown that positively charged IPEC formed the strongest top layers on the soil/ground surface, which resisted wind and water erosion.…”

“…The average values and confidence intervals are presented in Table1. The graphs and histograms show the average values of the corresponding parameters and confidence intervals as error bars.3 | RESULTS AND DISCUSSION3.1 | PDADMAC-PH IPEC formationIt has been shown previously(Panova et al, 2020;Panova, Drobyazko, et al, ), that, in neutral aqueous solutions, anionic PH electrostatically interact with cationic PDADMAC resulting in the forma-tion of a PDADMAC-PH IPECs stabilized by multiple salt bonds between ionic groups of both polyelectrolytes. At a equimolar ratio between anionic units of PH and cationic units of PDADMAC, Q(0) = (PH−) / (PDADMAC+) = 1, stoichiometric IPECs are formed insoluble in water.…”