INTEMA   05428
INSTITUTO DE INVESTIGACIONES EN CIENCIA Y TECNOLOGIA DE MATERIALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Development and characterization of chitosan hydrogel beads for application in cultivated soils
Autor/es:
ALVAREZ, V.; COLMAN, S.; SANCHEZ, L.; TOMADONI, B.; CASALONGUÉ, C.; SALCEDO, F.
Lugar:
Mar del Plata
Reunión:
Simposio; SLAP 2018-XVI Simposio Latinoamericano de Polímeros junto con el XIV Congreso Iberoamericano de Polímeros; 2018
Resumen:
INTRODUCTION Hydrogels are materials which have the capacity to absorb large quantities of water, more than 400 times its weight1 . Hydrogels have the ability to gradually release up to 95% of this stored water when the surroundings are dried out; and then rehydrate when exposed to water again. This process of storing water can last up to 2-5 years, time by which biodegradable hydrogel will decompose1 . Therefore, the use of biodegradable hydrogels in agriculture is a good strategy for moisture control in soils and to promote better growth and yield of crops exposed to adverse conditions such as water stress, and compatible with sustainable agriculture. Among biodegradable materials, chitosan (CH) is a natural cationic polymer with hydrophilic nature and excellent characteristics for hydrogel structure. CH hydrogel beads have been widely studied as carriers of micro or nanoparticles in the pharmaceutical and medical fields, where they have shown promise for controlled drug release, as well as biocompatibility with tissues and cells2 . Hence, the objective of this study was to obtain and characterize chitosan hydrogel beads for application in cultivated soils. EXPERIMENTAL METHODS Chitosan hydrogel beads were prepared by dissolving 3% w/v of CH (PARAFARM, Argentina) in acetic acid (5% v/v), under constant magnetic stirring for 4 hours. Then, the homogeneous chitosan solution was added dropwise with a pump into a coagulating solution (NaOH 2.5 M) in order to obtain the hydrogel beads (Fig. 1.A-C). Characterization of the beads was performed in terms of Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), swelling and gel fraction measurements.RESULTS AND DISCUSSION Chitosan hydrogel beads were obtained as shown in Fig. 2.A, and were dried at 25°C until constant weight (Fig. 2.B). Gel fraction of the obtained CH hydrogel beads was 85- 90%. TGA showed a first weight loss of around 20%, wich may correspond to the loss of adsorbed and bound water. The degradation of chitosan reached its maximum at 264°C and showed about 60% weight loss. CONCLUSION The obtained chitosan hydrogel beads could be a feasible tool for moisture control in soils, and also would be compatible with sustainable agriculture. The next step in this research is to analyse the effect of the hydrogels in plant bioassays using tomato as model. For this purpose, the relative water content (RWC) and growth parameters of plants are being measured, including germinative capacity of seeds.REFERENCES 1. Kalhapure A. et al., Curr Sci. 111(11), 1773-1779, 2016. 2. Rani M. et al., BioResources. 5(4), 2765-2807, 2010. ACKNOWLEDGMENTS This work was supported by CONICET, ANPCyT and UNMdP.