Berradi Achraf, Lafdali Ahlam, Ouazzani Naaila, Aziz Khalid, Mandi Laila, El Achaby Mounir, Kurniawan Tonni Agustiono, Aziz Faissal
Cadi Ayyad University, Faculty of Sciences Semlalia, Laboratory of Water Sciences, Microbial Biotechnologies and Natural Resources Sustainability, B.P. 2390, 40000, Marrakech, Morocco; National Center for Research and Studies on Water and Energy (CNEREE), Cadi Ayyad University, B. 511, 40000, Marrakech, Morocco.
Cadi Ayyad University, Faculty of Sciences Semlalia, Laboratory of Water Sciences, Microbial Biotechnologies and Natural Resources Sustainability, B.P. 2390, 40000, Marrakech, Morocco; National Center for Research and Studies on Water and Energy (CNEREE), Cadi Ayyad University, B. 511, 40000, Marrakech, Morocco; Cadi Ayyad University, Faculty of Science and Technology, Laboratory of Innovative Materials, Energy and Sustainable Development (IMED-Lab), B.P. 112, 40000, Marrakech, Morocco.
Int J Biol Macromol. 2025 Sep;323(Pt 1):146926. doi: 10.1016/j.ijbiomac.2025.146926. Epub 2025 Aug 21.
Water scarcity and inefficient irrigation methods continue to be major issues in agriculture, which consumes 70 % of freshwater. In this context, creating effective water management strategies is crucial, and superabsorbent polymers (SAPs) offer a promising new solution. However, traditional synthetic SAPs and hybrid SAPs with a lot of synthetic material contribute to microplastic pollution, making it urgent to find eco-friendly alternatives that deliver good performance while protecting the environment and supporting sustainability. To address this, a novel carboxymethyl cellulose (CMC)/sodium alginate (Na-Alg) hybrid hydrogel was prepared via free-radical graft copolymerization of acrylic acid (AA) and acrylamide (AM) onto a polysaccharide backbone in aqueous solution, designed for agricultural water management. Design-Expert software was employed to furnish 11 hydrogel formulations to minimize acrylic monomer content while maximizing swelling capacity. The optimal formulation CMC-6 (AA/CMC = 3.25, Na-Alg/CMC = 0.6) revealed a maximum water absorption capacity (1636.69 g/g). FTIR and XRD analysis confirmed successful grafting and crosslinking reactions, while SEM analysis revealed a highly porous morphology, confirming the high swelling capacities reached. TGA and rheological analysis demonstrated that CMC-6 exhibited good thermal and mechanical stability. The swelling behavior was evaluated under varying pH, salinity, and temperature conditions. The SAP maintained a good swelling capacity across a wide pH range, reaching the maximum at pH 8. Due to lower osmotic pressure, the swelling capacity decreased as the concentration of NaCl solution increased. It ranged from 307 g/g to 164.75 g/g as the concentration went from 0.3 wt% to 1.2 wt%. The effect of cation charge followed the order Na > Ca > Al, demonstrating that multivalent cations reduce swelling through additional cross-linking. Smaller cations (Na and Mg) facilitated water penetration compared to large ones. CMC-6 showed a thermoresponsive behavior, and the water retention test highlighted its ability to retain water for five days. Additionally, it demonstrated good reusability through reswelling and water re-retention over multiple cycles. These responsive and durable properties make it a promising candidate for sustainable agricultural practices.
水资源短缺和低效的灌溉方式仍然是农业领域的主要问题，农业消耗了70%的淡水。在这种背景下，制定有效的水资源管理策略至关重要，而高吸水性聚合物（SAPs）提供了一种有前景的新解决方案。然而，传统的合成SAPs以及含有大量合成材料的混合SAPs会导致微塑料污染，因此迫切需要找到既性能良好又能保护环境并支持可持续发展的环保替代品。为解决这一问题，通过在水溶液中将丙烯酸（AA）和丙烯酰胺（AM）自由基接枝共聚到多糖主链上，制备了一种新型的羧甲基纤维素（CMC）/海藻酸钠（Na-Alg）混合水凝胶，用于农业用水管理。使用Design-Expert软件提供了11种水凝胶配方，以尽量减少丙烯酸单体含量，同时最大化溶胀能力。最佳配方CMC-6（AA/CMC = 3.25，Na-Alg/CMC = 0.6）显示出最大吸水率（1636.69 g/g）。傅里叶变换红外光谱（FTIR）和X射线衍射（XRD）分析证实了接枝和交联反应的成功，而扫描电子显微镜（SEM）分析揭示了高度多孔的形态，证实达到了高溶胀能力。热重分析（TGA）和流变学分析表明CMC-6具有良好的热稳定性和机械稳定性。在不同的pH值、盐度和温度条件下评估了溶胀行为。该高吸水性聚合物在较宽的pH范围内保持良好的溶胀能力，在pH 8时达到最大值。由于渗透压较低，随着氯化钠溶液浓度的增加，溶胀能力下降。当浓度从0.3 wt%增加到1.2 wt%时，溶胀能力范围从307 g/g降至164.75 g/g。阳离子电荷的影响顺序为Na > Ca > Al，表明多价阳离子通过额外的交联降低溶胀。与大阳离子相比，较小的阳离子（Na和Mg）促进了水的渗透。CMC-6表现出热响应行为，保水测试突出了其保水五天的能力。此外，它通过多次循环的再溶胀和再保水表现出良好的可重复使用性。这些响应性和耐久性使其成为可持续农业实践的有前景的候选材料。
