Optimización del parámetro de empaquetamiento del tensioactivo para la estabilización del carbono orgánico del suelo...

This study demonstrates how the packing parameter (P) of cationic surfactants governs the efficacy of organo-bentonites in stabilizing soil organic carbon (SOC). A series of organo-bentonites, synthesized with single- and double-chain surfactants (C12-C18), were evaluated for their capacity to stabilize labile SOC. Higher P values promoted denser hydrophobic domains, primarily on the external surface of the bentonite, which enhanced the adsorption capacity for potassium fulvate (FA, the proxy for SOC). Didodecyldimethylammonium bromide-modified bentonite (DDAB-Bent), with the highest packing parameter (P = 0.5-0.6), achieved the highest FA equilibrium adsorption (428.93 mg/g). In soil incubation studies, DDAB-Bent reduced cumulative carbon mineralization by 40.18% compared to the control. In a 30-day pot experiment with Chinese cabbage, DDAB-Bent increased total SOC content by 35.42%, mineral-associated organic carbon (MAOC) by 51.76%, and plant biomass by 28%. Molecular dynamics simulations of the confined interlayer confirmed that higher P values lead to more compact surfactant aggregates and stronger FA adsorption. This study therefore validates the packing parameter as a key design tool for engineering organo-bentonites for enhanced SOC stabilization in agricultural soils.