Lavlinskaya Maria S, Sorokin Andrey V
Biophysics and Biotechnology Department, Voronezh State University, 1 Universitetskaya Square, 394018 Voronezh, Russia.
Polymer Science and Colloid Chemistry Department, Voronezh State University, 1 Universitetskaya Square, 394018 Voronezh, Russia.
Gels. 2024 Dec 5;10(12):797. doi: 10.3390/gels10120797.
Carboxymethyl cellulose sodium salt (CMC)-based superabsorbents are promising materials for the development of agricultural matrices aimed at water management and slow-release fertilizer production. However, an increase in the CMC content tends to reduce their water-absorbing capacity. This study aims to develop a cost-effective method for producing eco-friendly superabsorbents with enhanced water-absorbing capacity by incorporating a porogen and employing lyophilization. Superabsorbents containing 10 wt% CMC (CMC-SAPs) were synthesized via free radical polymerization with the addition of 0, 5, or 10 wt% ammonium carbonate as a porogen, followed by lyophilization. The synthesized CMC-SAPs were characterized using Fourier-transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry, and X-ray diffraction. The results revealed that CMC-SAPs prepared with the incorporation of a porogen and/or subjected to lyophilization exhibited well-developed surfaces featuring macropores and cavities. Incorporating 5 wt% ammonium carbonate as a porogen, followed by lyophilization, increased the equilibrium swelling ratio to 61%. This improvement was attributed to the enhanced surface morphology of the modified CMC-SAPs, which facilitated water molecule diffusion into the SAP matrix, as confirmed by open porosity measurements. This hypothesis was further supported by the diffusion coefficient values, which were higher for porogen-containing and lyophilized SAPs compared to unmodified samples. Moreover, the CMC-SAPs demonstrated good reusability. Thus, the combination of porogen incorporation and subsequent lyophilization represents a promising approach for enhancing the water uptake capacity of CMC-based composite superabsorbents for sustainable agricultural applications.
基于羧甲基纤维素钠盐（CMC）的高吸水性聚合物是用于开发旨在进行水分管理和生产缓释肥料的农业基质的有前景的材料。然而，CMC含量的增加往往会降低其吸水能力。本研究旨在开发一种经济有效的方法，通过加入致孔剂并采用冻干法来生产具有增强吸水能力的环保型高吸水性聚合物。通过自由基聚合，添加0、5或10 wt%的碳酸铵作为致孔剂，然后进行冻干，合成了含有10 wt% CMC的高吸水性聚合物（CMC-SAPs）。使用傅里叶变换红外光谱、扫描电子显微镜、热重分析、差示扫描量热法和X射线衍射对合成的CMC-SAPs进行了表征。结果表明，通过加入致孔剂和/或进行冻干制备的CMC-SAPs表现出具有大孔和空洞的发达表面。加入5 wt%的碳酸铵作为致孔剂，然后进行冻干，使平衡溶胀率提高到61%。这种改善归因于改性CMC-SAPs增强的表面形态，这促进了水分子扩散到高吸水性聚合物基质中，开孔率测量证实了这一点。扩散系数值进一步支持了这一假设，与未改性样品相比，含致孔剂和冻干的高吸水性聚合物的扩散系数值更高。此外，CMC-SAPs表现出良好的可重复使用性。因此，加入致孔剂和随后的冻干相结合是一种有前景的方法，可提高基于CMC的复合高吸水性聚合物的吸水能力，用于可持续农业应用。
