Development of Separation and Concentration of a Trace of Substance by Thermo-sensitive Heteropolymer Gels

研究了由苯乙烯硫酸钠（SSS）和乙烯基苄基三甲基氯化铵（VBTA）组成的两性聚电解质凝胶在不同温度下对疏水性芳香族化合物的吸附性能。使用N-异丙基丙烯酰胺（NIPA）凝胶，也进行了相应的实验进行比较。在室温下，NIPA凝胶几乎不吸附芳香族化合物，而在较高温度下吸附它们。与NIPA凝胶的吸附行为相反，SSS-VBTA凝胶对芳香族化合物的吸附量随着温度的升高而降低。此外，它已被证明，SSS-VBTA凝胶可以重复吸附双酚-A在298 K和解吸它在353 K的变温操作：这种吸附/解吸行为的SSS-VBTA凝胶是截然相反的NIPA凝胶。这表明SSS-VBTA凝胶更适合于从非常稀的水溶液中吸附去除疏水性芳族化合物，因为使用NIPA凝胶加热大量的水以吸附疏水性化合物需要大量的能量。接枝在多孔硅胶颗粒内表面的SSS-VBTA凝胶在变温条件下对疏水性芳香族化合物表现出可逆的吸附和脱附。

The adsorption property of the polyampholyte gel composed of sodium styrene sulfate (SSS) and vinylbenzyl trimethylammonium chloride (VBTA) has been investigated at different temperatures with hydrophobic aromatic compounds as adsorbate. Using the N-isopropylacrylamide (NIPA) gel, the corresponding experiments were also carried out for comparison. At room temperature, the NIPA gel hardly adsorbed the aromatic compounds, while it adsorbed them at higher temperatures. In contrast with the adsorption behavior of the NIPA gel, the adsorption amounts of the aromatic compounds for the SSS-VBTA gel decreased with increasing temperature. Also, it has been demonstrated that the SSS-VBTA gel can repeatedly adsorb bisphenol-A at 298 K and desorb it at 353 K by the temperature-swing operation : this adsorption/desorption behavior of the SSS-VBTA gel is diametrically opposite to that of the NIPA gel. This shows that the SSS-VBTA gel is much more suitable for the adsorption removal of the hydrophobic aromatic compounds from very dilute aqueous solutions, because a vast amount of energy is required for heating a large amount of water to adsorb the hydrophobic compounds using the NIPA gel. The SSS-VBTA gel which was grafted on the innersurface of porous silica gel particles showed ad-and desorption reversibly for hydrophobic aromatic compounds under the temperature-swing operation.