Natsir Taufik Abdillah, Iknawati Alvina Mita, Wanadri Iqbal Dian, Siswanta Dwi, Lusiana Retno Ariadi, Cahyaningrum Sari Edi
Department of Chemistry, Universitas Gadjah Mada, Yogyakarta, Indonesia.
Department of Chemistry, Diponegoro University, Semarang, Indonesia.
Heliyon. 2024 Dec 19;11(1):e41378. doi: 10.1016/j.heliyon.2024.e41378. eCollection 2025 Jan 15.
In agriculture, fertilizers are important for plant growth. Among them, conventional fertilizers, particularly urea fertilizers, are popular owing to their low cost and high nitrogen content. However, their use often leads to uneven nitrogen absorption and environmental pollution. Slow-release fertilizers (SRFs), particularly those based on chitosan, offer a solution. This research aims to produce biodegradable chitosan/citric acid/calcium-urea (CS/St/Ca-urea) films to increase the absorption efficiency and use of artificial nitrogen fertilizers (especially urea). Herein, chitosan/citric acid/calcium (CS/St/Ca) films were synthesized and applied as SRFs. Chitosan was dissolved in 1 % acetic acid and added to citric acid at 55 °C for 24 h. Then, calcium oxide (CaO) and urea were added to the CS/St mixture and stirred until homogeneous. Subsequently, the membrane product was characterized by ATR-IR, SEM-EDX, and elemental analysis and its nitrogen solubility was determined using a UV-vis spectrophotometer. The physical properties of the CS/St/Ca were investigated via swelling, hydrophobicity, and tensile strength tests. Results showed that a CS/St at weight ratio of 1:1 can increase the tensile strength by up to 13.6 %. The addition of a filler with a Ca additive, as well as the addition of CaO, can increase the mechanical strength of the membrane. The CS/St/Ca film membranes can function optimally as a urea SRF coating material with a release rate of 3.37-9.46 ppm day. The applied kinetic model follows the Higuchi kinetic model, with an value of 0.9505.
在农业中，肥料对植物生长很重要。其中，传统肥料，特别是尿素肥料，因其成本低、氮含量高而广受欢迎。然而，它们的使用往往导致氮吸收不均和环境污染。缓释肥料（SRF），特别是基于壳聚糖的缓释肥料，提供了一种解决方案。本研究旨在制备可生物降解的壳聚糖/柠檬酸/钙 - 尿素（CS/St/Ca - 尿素）薄膜，以提高人工氮肥（尤其是尿素）的吸收效率和利用率。在此，合成了壳聚糖/柠檬酸/钙（CS/St/Ca）薄膜并将其用作缓释肥料。将壳聚糖溶解在1%的乙酸中，在55°C下加入柠檬酸中反应24小时。然后，将氧化钙（CaO）和尿素加入到CS/St混合物中并搅拌至均匀。随后，通过ATR - IR、SEM - EDX和元素分析对膜产品进行表征，并使用紫外可见分光光度计测定其氮溶解度。通过溶胀、疏水性和拉伸强度测试研究了CS/St/Ca的物理性质。结果表明，重量比为1:1的CS/St可使拉伸强度提高高达13.6%。添加含Ca添加剂的填料以及CaO可提高膜的机械强度。CS/St/Ca薄膜可作为尿素缓释肥料涂层材料发挥最佳功能，释放速率为3.37 - 9.46 ppm/天。应用的动力学模型遵循Higuchi动力学模型， 值为0.9505。
