Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.
Molecules. 2013 Jul 18;18(7):8461-72. doi: 10.3390/molecules18078461.
Poly(ethyl hydrazide)-grafted oil palm empty fruit bunch fibre (peh-g-opefb) was successfully prepared by heating poly(methyl acrylate)-grafted opefb (pma-g-opefb) at 60 °C for 4 h with a solution of hydrazine hydrate (15% v/v) in ethanol. The Fourier transform infrared spectrum of the product shows a secondary amine peak at 3267 cm⁻¹, with amide carbonyl peaks at 1729 cm⁻¹ and 1643 cm⁻¹. The chelating ability of peh-g-opefb was tested with copper ion in aqueous solution. A batch adsorption study revealed that maximum adsorption of copper ion was achieved at pH 5. An isotherm study showed the adsorption follows a Langmuir model, with a maximum adsorption capacity of 43.48 mg g-1 at 25 °C. A kinetic study showed that the adsorption of copper ion rapidly reaches equilibrium and follows a pseudo-second-order kinetic model, with a constant rate of 7.02 × 10⁻⁴ g mg⁻¹ min⁻¹ at 25 °C. The Gibbs free energy, ∆G⁰, value is negative, indicating a spontaneous sorption process. Entropy, ∆S⁰, gives a positive value, indicating that the system is becoming increasingly disordered after the adsorption of copper ion. A positive enthalpy value, ∆H⁰, shows that the endothermic process takes place during the adsorption and is more favourable at high temperatures.
聚（乙基酰肼）接枝油棕空果串纤维（PEH-G-OPEFB）是通过将聚（甲基丙烯酸酯）接枝油棕空果串（PMA-G-OPEFB）在 60°C 加热 4 小时，与乙腈溶液中的水合肼（15%v/v）反应成功制备的。产物的傅里叶变换红外光谱在 3267cm⁻¹处显示出仲胺峰，酰胺羰基峰在 1729cm⁻¹和 1643cm⁻¹处。PEH-G-OPEFB 的螯合能力用铜离子在水溶液中进行了测试。批量吸附研究表明，在 pH 值为 5 时，铜离子的最大吸附量达到。等温线研究表明，吸附遵循朗缪尔模型，在 25°C 时，最大吸附容量为 43.48mg g-1。动力学研究表明，铜离子的吸附迅速达到平衡，并遵循拟二级动力学模型，在 25°C 时，速率常数为 7.02×10⁻⁴g mg⁻¹min⁻¹。吉布斯自由能，∆G⁰，值为负，表明吸附过程是自发的。熵，∆S⁰，给出正值，表明铜离子吸附后系统变得越来越无序。正的焓值，∆H⁰，表明在吸附过程中发生了吸热过程，在高温下更有利。
