Eco-friendly and biodegradable dimethylacrylamide/starch hydrogels for controlled release of urea and its water retention
Abstract
In this study, we focused on the synthesis of polymeric hydrogels that will support the sorption and controlled release of urea, which is a rich nitrogen source, from aqueous solutions and their usability in agricultural applications. N, N-Dimethylacrylamide (DMAAm) and Starch (St) were selected as monomers, and their superior properties, such as chemical stability, high sorption properties, biocompatibility, and the presence of modifiable groups, were utilized. A redox polymerization technique was used to create a poly(DMAAm-co-St)-based hydrogel that was then modified with acidic and basic agents to improve the properties of starch. The synthesized acid- and base-modified hydrogels were named DSt, DSt1, and DSt2, respectively. Swelling analyses were performed to examine the structural and morphological properties of DSt, DSt1, and DSt2 hydrogels, and Fourier-Transform Infrared Spectroscopy (FT-IR) and Thermogravimetric Analyzers (TGA) were used. Intense cross-linking, porosity, and the presence of hydrophilic groups were successfully detected by instrumental analysis and swelling results. The successful results of urea sorption by DSt, DSt1, and DSt2 hydrogels show that they can both minimize the harmful effects of urea in the environment and contain the nitrogen necessary for plants. At the same time, urea sorption behaviors were evaluated in terms of sorption isotherms and thermodynamic properties, and it was observed that urea sorption conformed to the Langmuir isotherm. The urea release results showed that DSt, DSt1, and DSt2 hydrogels exhibited different release properties in different pH solutions, and these results reached 94% at pH 6–8, 100% at pH 6, and 100% at pH 8–10, respectively. As a result of the gradual decrease in the water resources on the earth, the increase in the use of fertilizers in agricultural production, and the insufficient use of fertilizers, our study draws attention to the development and support of materials that absorb/store water, and forms of controlled release fertilizers and provides potential ease of application
Keywords
Controlled release, Hydrogel, Nitrogen loss, Starch, Water retention
Supporting Institution
Van Yuzuncu Yıl University BAP
Project Number
FBA-2019-7912
Thanks
This work is supported by the Van Yuzuncu Yıl University BAP with grant # FBA-2019-7912.
References
- [1]. Dawson C.J., Hilton J., “Fertiliser Availability in a Resource-Limited World: Production and Recycling of Nitrogen and Phosphorus”, Food Policy, 36, (2011), S14-S22.
- [2]. Ghafoor I., Habib-ur-Rahman M., Ali M., Afzal M., Ahmed W., Gaiser T., Ghaffar A., “Slow-Release Nitrogen Fertilizers Enhance Growth, Yield, NUE In Wheat Crop and Reduce Nitrogen Losses Under an Arid Environment”, Environmental Science and Pollution Research, 28, (2021), 43528–43543.
- [3]. Jarvis S.C., “Nitrogen Cycling and Losses from Dairy Farm”, Soil Use and Management, 9(3), (1993), 99-105.
- [4]. Crusciol C.A.C., Almeida D.S., Alves C.J., Soratto R.P., Krebsky E.O., Spolidorio E.S., “Can Micronized Sulfur in Urea Reduce Ammoniacal Nitrogen Volatilization and Improve Maize Grain Yield?”, Journal of Soil Science and Plant Nutrition, 19, (2019), 701–711.
- [5]. Rahman M.H., Ahmad I., Wang D. et al (2020) Influence of Semi-Arid Environment on Radiation Use Efficiency and Other Growth Attributes of Lentil Crop. Environ Sci Pollut Res 28:13697–13711. https://doi. org/10.1007/s11356-020-11376-w.
- [6]. Rao E.P., Puttanna K., “Nitrates, Agriculture and Environment”, Current Science, 79(9), (2000), 1163-1168.
- [7]. Bowles T.M., Atallah S.S., Campbell E.E., Gaudin A.C.M., Wieder W.R., Grandy A.S., “Addressing Agricultural Nitrogen Losses in a Changing Climate”, Nature Sustainability, 1, (2018), 399–408.
- [8]. Ersen Dudu T., Alpaslan D., Aktas N., “Urea Uptake and Release by Novel Macrogels from Dimethylacrylamide”, Communications in Soil Science and Plant Analysis, 50(18), (2019), 2278–2293.
- [9]. Neethu T.M., Dubey P.K., Kaswala A.R., “Prospects and Applications of Hydrogel Technology in Agriculture”, International Journal of Current Microbiology and Applied Sciences, 7(5), (2018), 3155- 3162.
- [10]. Das D., Prakash P., Rout P.K., Bhaladhare S., “Synthesis and Characterization of Superabsorbent Cellulose-Based Hydrogel for Agriculture Application”, Starch – Stärke, 73, (2021), 1900284.