甲基橙/水滑石复合颜料制备与表征

Preparation and characterization of methyl orange/hydrotalcite composite pigment

采取共沉淀法制备不同阴离子插层的锌铬水滑石(ZnCr-LDHs),通过ZnCr-LDHs吸附甲基橙(MO)制备有机-无机复合颜料。采用XRD、FT-IR和TG-DTA对不同阴离子插层的ZnCr-LDHs结构和热稳定性能进行表征,研究了吸附剂种类、吸附温度、MO初始浓度和溶液pH值等因素对复合颜料中MO吸附量的影响。研究结果表明:ZnCr-LDHs结构参数的差异与插层阴离子的种类、电荷和空间结构有关,并影响其对MO的吸附量。ZnCr-CO_3-LDHs的层间距最小,但对MO的吸附容量最大,ZnCr-CO_3-LDHs吸附MO至层板上形成复合颜料。当反应温度313 K,MO初始浓度为100 mg·L^(-1),吸附时间为2 h时,制备得到的复合颜料中MO吸附容量为88.56 mg·g^(-1)。酸性条件下ZnCr-CO_3-LDHs对MO的吸附容量明显高于碱性条件下,溶液初始pH值为3时,吸附容量达到最大值为190.93 mg·g^(-1)。

Zinc chromium hydrotalcites with different intercalation anion(ZnCr-LDHs)were prepared by co-precipitation method,and methyl orange(MO)pigment was adsorbed to ZnCr-LDHs to prepare composite pigment.The structure and thermal stability of ZnCr-LDHs with different intercalation anions were characterized by XRD,FT-IR and TG-DTA.The effects of absorbent type,adsorption temperature,and initial concentration of MO and pH value on the adsorption capacity of MO in composite pigments were discussed.The results showed that the differences in structural parameters of ZnCr-LDHs was related to the type,charge and spatial structure of intercalated anions,and also affected its adsorption capacity to MO.ZnCr-CO 3-LDHs had the smallest interlayer spacing but had the largest adsorption capacity for MO.In addition,ZnCr-CO 3-LDHs adsorbed MO onto the laminate to form composite pigments.When the reaction temperature was 313K,the initial concentration of MO was 100 mg·L^-1,and the adsorption reaction time was 2 h,the adsorption capacity of MO in the composite pigment reached 88.56 mg·g^-1.The adsorption capacity of ZnCr-CO 3-LDHs to MO under acidic conditions was significantly higher than that under alkaline conditions.When the pH value of solution was 3,the adsorption capacity reached the maximum value of 190.93 mg·g^-1.