高岭土对聚苯乙烯磺酸钠的吸附作用(Ⅰ)——温度和氯化钠的影响

研究在30℃、45℃及60℃下和不同的NaCl浓度下,高岭土对聚苯乙烯磺酸钠(PSSNa)的吸附。结果表明,在不加NaCl情况,吸附量不随温度改变,吸附热等于零,存在多层吸附,吸附等温线与PSSNa的η(?)p/c~(-C)曲线存在一定对应关系。加入NaCl后,吸附热仍等于零,但吸附量大大提高,不存在多层吸附,随着PSSNa浓度增加,吸附量反而稍有下降。吸附前后高岭土晶格参数不变。认为高岭土对PSSNa的吸附是物理吸附,多层吸附的存在和NaCl提高吸附量均与PSSNa的侧基带有苯环和聚阴离子卷曲有关。

THE ADSORPTION OF SODIUM POLYSTYRENE SULFONATE ON KAOLIN

The adsorption of sodium polystyrene sulfonate (PSSNa) on kaolin from aqueous NaCl solutions of various concentrations at 30℃, 45℃ and 60℃ has been studied. In the absence of NaCl, the amount of adsorption was found to be independent of temperature, i.e. heat of adsorption, ΔH=0. The shape of adsorption isotherm indicates the presence of multilayer adsorption and some correlation between the isotherm and the nnnnnnaP/C - C curve of PSSNa solution has been found. In aqueous NaCl solution, heat of adsorption is still equal to zero, but the amount of adsorption increases considerably, and the isotherm does not show multilayer adsorption. The crystalline indices of kaolin was found unchanged after the adsorption of PSSNa. It is supposed that the adsorption of PSSNa on kaolin is physical in nature. The multilayer adsorption and the increase of adsorption by NaCl may be attributed to the presence of phenyl groups in the side chain of PSSNa and the coiling of polyanion PSS-. The mechanism of adsorption has been discussed.