复配抗霉剂与碱性激发材料制备抗霉型磷石膏及机理研究OA

Phosphogypsum building materials are prone to mold contamination in warm and humid regions,which restricts their comprehensive utilization.To address this issue,an organic antifungal system composed of tetradecyltrimethylammonium chloride(TTAC)and polyhexamethylene biguanide hydrochloride(PHMB)was developed in this study,and coupled with a CaO-slag-aluminate cement alkali-activated system to synergistically improve the mold resistance and mechanical performance of phosphogypsum.An antifungal model was established through microstructural analysis and theoretical calculation,and the mold inhibition mechanism was discussed.The results show that the synergistic"membrane disruption-penetration"effect of TTAC and PHMB reduces the combined fungistatic index to 0.15 to 0.75,significantly lowering the minimum inhibitory concentration.The alkali-activated system refines the average pore diameter of the matrix to 0.104 µm by promoting the formation of ettringite and C-S-H gel,forming a dense physical barrier.The antifungal agents are stably immobilized in the gel network via the"electrostatic anchoring-hydrogen bond crosslinking"mechanism,which,together with the pore barrier and alkaline environment,constitutes a triple synergistic antifungal mechanism involving physical barrier,chemical sustained release and metabolic inhibition.After optimization,the specimens maintain Grade 0 mold resistance in a high-humidity environment for 28 d,with a compressive strength of 11.7 MPa and a softening coefficient of 0.72,which improves the quality of phosphogypsum wall materials and promotes the large-scale consumption of phosphogypsum.