Low charge density nanometric ions were recently shown to bind strongly to neutral hydrated matter in aqueous solution. This phenomenon, called the (super-)chaotropic effect, arises from the partial dehydration of both the nano-ion and the solute, leading to a significant gain in enthalpy. Here, we investigate the chaotropic effect of the polyoxometalate α-PW₁₂O₄₀³⁻ on the triblock copolymer P84: (EO)₁₉(PO)₄₃(EO)₁₉ with (EO)₁₉ the polyethoxylated and (PO)₄₃ the polypropoxylated chains. The combination of phase diagrams, spectroscopic (nuclear magnetic resonance) and scattering (small angle neutron/X-ray scattering) techniques revealed that: (i) below the micellization temperature of P84, PW₁₂O₄₀³⁻ exclusively binds to the propylene oxide moiety of P84 unimers; and (ii) above the micellization temperature, PW₁₂O₄₀³⁻ mostly adsorbs on the ethylene oxide micellar corona. The preferential binding of the PW₁₂O₄₀³⁻ to the PPO chain over the PEO chains suggests that the binding is driven by the chaotropic effect and is reinforced by the hydrophobic effect. At higher temperatures, copolymer micellization leads to the displacement of PW₁₂O₄₀³⁻ from the PPO chain to the PEO chains. This study deepens our understanding of the subtle interplay between the chaotropic and hydrophobic effects in complex salt-organic matter solutions.