Macroporous Hydrogels for Soil Water Retention

Amidst the challenges of climate change and drought, water scarcity is an issue that is persistent in regions of semi-arid climate. These conditions negatively impact agricultural production. The goal of this project was to successfully increase water retention using a macroporous hydrogel that absorbs water more rapidly via capillary action. The macroporous hydrogels were templated using high internal phase emulsions made with cyclohexane and olive oil. These emulsions were then polymerized using the catalyst N,N,N’,N’-tetramethyl-ethylenediamine (TEMED) and then air dried. These macroporous hydrogels were then integrated into sandy soil. The water holding capacity and capillary rise were tested to measure the available water content and water uptake rates. Different amounts of the hydrogel were incorporated within the soil in order to measure the effect that the presence of these hydrogels have on soil water retention. The treated soil exhibited significantly higher water retention than the untreated soil. The higher water uptake rate is due to capillary action, and the treated soil shows a higher maximum uptake due to porosity. A scanning electron microscope (SEM) analysis showed that a highly interconnected structure was formed within the macroporous hydrogel. The hydrogel investigated has displayed a higher water uptake and increased absorbance due to the internal macroporous structure when compared to current super absorbent polymers.