Hardi Jaya, Tijsseling Tristan, Takase Hayato, Yoshida Masahiro, Shiomori Koichiro, Matsune Hideki
University of Miyazaki, Miyazaki, Japan.
Department of Chemistry, Tadulako University, Palu, Indonesia.
R Soc Open Sci. 2025 Aug 6;12(8):242274. doi: 10.1098/rsos.242274. eCollection 2025 Aug.
A chitosan (CH) cryogel is a supermacropore material that can be used as an adsorbent. However, its utilization as a metal adsorbent is limited due to its low stability in acidic conditions. A CH cryogel has been modified using tripolyphosphate (TPP) and tannic acid (TA) as biocompatible cross-linkers. TPP increases the stability of the cryogels in acidic solutions, and TA increases their mechanical properties. CH-TPP, CH-TPP2.5-TA, CH-TPP5-TA and CH-TPP7.5-TA cryogels were applied for the adsorption of Cu ions. The CH-TPP-TA cryogels reached optimum conditions at pH 5.0 with a removal efficiency of 91-96%. The adsorption of Cu ions by CH-TPP-TA cryogels fits the nonlinear Freundlich isotherm, or Cu is adsorbed on the heterogeneous cryogels' surfaces. CH-TPP5-TA has an adsorption capacity up to 109 mg g at an initial Cu concentration of 500 mg l. The adsorption kinetics of Cu ions follows pseudo-second order. It is interpreted that the adsorption mechanism is generally through chemical interactions. Copper elements are proven to be adsorbed by the cryogel, which is detected by energy-dispersive X-ray analysis. The photographic results show that Cu ions can be adsorbed into the inner layer of the cryogel. Finally, the CH-TPP-TA cryogel is promising to be used as a biocompatible adsorbent for copper.
壳聚糖（CH）冷冻凝胶是一种可用作吸附剂的超大孔材料。然而，由于其在酸性条件下稳定性较低，限制了其作为金属吸附剂的应用。已使用三聚磷酸钠（TPP）和单宁酸（TA）作为生物相容性交联剂对CH冷冻凝胶进行了改性。TPP提高了冷冻凝胶在酸性溶液中的稳定性，TA增强了其机械性能。将CH-TPP、CH-TPP2.5-TA、CH-TPP5-TA和CH-TPP7.5-TA冷冻凝胶用于铜离子的吸附。CH-TPP-TA冷冻凝胶在pH 5.0时达到最佳条件，去除效率为91-96%。CH-TPP-TA冷冻凝胶对铜离子的吸附符合非线性弗伦德利希等温线，即铜吸附在非均相冷冻凝胶表面。在初始铜浓度为500 mg/L时，CH-TPP5-TA的吸附容量高达109 mg/g。铜离子的吸附动力学符合准二级动力学。据解释，吸附机制通常是通过化学相互作用。通过能量色散X射线分析证实铜元素被冷冻凝胶吸附。照片结果表明铜离子可被吸附到冷冻凝胶的内层。最后，CH-TPP-TA冷冻凝胶有望用作铜的生物相容性吸附剂。
