Ion-permeation-resistant modified composite silicon powder as well as preparation method and application thereof

A preparation method of the anti-ion-permeation modified composite silicon powder comprises the following steps: 1) sequentially modifying silicon powder by adopting macroporous weak-acid acrylic cation exchange resin and a polyvinyl alcohol solution to obtain modified silicon powder; 2) uniformly mixing silicic acid, an alcohol solvent and water, then dropwise adding a titanium source solution, and carrying out stirring reaction at room temperature to obtain nano TiO2 sol; and 3) adding the modified silicon powder into the obtained nano TiO2 sol, uniformly mixing, and drying to obtain the anti-ion permeation modified composite silicon powder. On the premise of reducing the cost of the silicon powder, the inherent problems of high water demand, high viscosity and the like when the traditional silicon powder is applied to concrete can be effectively solved, and the ion adsorption performance, the overall durability and the like of the concrete are effectively improved; efficient application of low-quality and