Novel alginate-cellulose nanofiber–poly(vinyl alcohol) hydrogels for carrying and delivering nitrogen, phosphorus and potassium chemicals

Authors: LIU, SHILIANG - LOUISIANA STATE UNIVERSITY; WU, QINGLIN - LOUISIANA STATE UNIVERSITY; SUN, XIUXUAN - LOUISIANA STATE UNIVERSITY; YUE, YIYING - NANJING FORESTRY UNIVERSITY; TUBANA, BRENDA - LSU AGCENTER; YANG, RONGJIE - SICHUAN AGRICULTURAL UNIVERSITY; CHENG, HUAI

Submitted to: International Journal of Biological Macromolecules
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/11/2021
Publication Date: 1/13/2021
Citation: Liu, S., Wu, Q., Sun, X., Yue, Y., Tubana, B., Yang, R., Cheng, H.N. 2021. Novel alginate-cellulose nanofiber–poly(vinyl alcohol) hydrogels for carrying and delivering nitrogen, phosphorus and potassium chemicals. International Journal of Biological Macromolecules. 172:330-340. https://doi.org/10.1016/j.ijbiomac.2021.01.063.
DOI: https://doi.org/10.1016/j.ijbiomac.2021.01.063

Interpretive Summary: Fertilizers are needed in agriculture because they supply one or more nutrients essential to the growth of plants. One of the methods whereby the effectiveness of a fertilizer can be improved is to encapsulate the fertilizer such as to produce slow (or controlled) release of the nutrients and to modify the water release properties of the soil. Improved or better methods of encapsulation are always desirable. In this work, we have prepared a new carrier system for fertilizers, using only non-toxic and biodegradable materials, viz., alginate, nanocellulose, and poly(vinyl alcohol). Both the slow-release and the water retention properties of this carrier system are satisfactory. This work may be useful in future formulation of fertilizers that can reduce the impact on the environment and has specific benefits for the drought-prone or fertilizer-loss regions.

Technical Abstract: Novel nanocomposite hydrogels were successfully prepared by blending and crosslinking sodium alginate (SA), poly(vinyl alcohol) (PVA) and cellulose nanofibers (CNFs) in the presence of a fertilizer formulation containing nitrogen (N), phosphorus (P) and potassium(K). The hydrogels had amacroporous flexible core and a microporous semi- interpenetrating polymer network (IPN) shell. The crystalline nature of the NPK chemicals was retained in the hydrogel nanocomposite network. Furthermore, the SA/CNF/PVA-based hydrogels showed a higher water-retention capacity in both deionized water and mixed soil. The swelling behavior in various physiological pH, salt and alkali solutions exhibited good sensitivity. The NPK release from SA/CNF/NPK and SA/CNF/ PVA/NPK hydrogels was controlled by Fickian diffusion in both water and soil based on the Korsmeyer-Peppas release kinetics model (n < 0.5). Therefore, the prepared hydrogels have the potential for applications in drought-prone and/or fertilizer-loss regions for future development of precision agriculture and horticulture.