CaCO3/硅灰石复合材料制备及其疏水性能研究

以天然硅灰石为原料，采用一步碳化法制得CaCO₃/硅灰石（W@C）复合材料，并对其表面进行有机改性。采用BET、XRD、SEM、FT-IR和TG-DSC等表征复合材料的比表面积以及改性前后产物的物相组成、形貌、基团和热稳定性。结果表明:当CaO添加量为25%、碳化温度为15℃、CO₂流速为0.08 m3/h、聚乙二醇用量为4.37 g/L时，可制得比表面积为15.28 m2/g的W@C复合材料，其比表面积比天然硅灰石提高了500%。W@C复合材料未改性时，接触角为19.37°，活化指数为0；采用1.5%硬脂酸钠改性W@C复合材料，接触角和活化指数分别增大至118.02°，99.9%，疏水性能显著提高。硬脂酸钠通过物理吸附包覆在W@C复合材料表面。 

Preparation and Hydrophobic Properties of CaCO3/Wollastonite Composites

CaCO₃/wollastonite (W@C) composites were prepared from natural wollastonite through one-step carbonization method, and the surface was organically modified. BET、XRD、SEM、FT-IR and TG-DSC were used to characterize the specific surface area of the composites and the phase composition morphology, group and thermal stability of the products before and after modification. The results showed that the W@C composites with a specific surface area of 15.28 m2/g was obtained when the amount of CaO added was 25%, the carbonization temperature was 15℃, the CO₂ flow rate was 0.08 m3/h, and the amount of polyethylene glycol (PEG) content was 4.37 g/L. The specific surface area of the obtained product was 500% higher than that of natural wollastonite. When the W@C composite was not modified, the contact angle was 19.37° and the activation index was 0. When the W@C composite was modified with 1.5% sodium stearate, the contact angle and activation index increased to 118.02° and 99.9%, respectively, and the hydrophobicity was significantly improved. Sodium stearate was coated on the surface of the W@C composites by physical adsorption.