Cellulose-based stimuli-responsive hydrogels

Starch and its Potential Applications as a Biomaterial for Hydrogels with Agricultural Purposes: A Mini-review

“…These characteristics have given hydrogel-type materials a particular interest in the agricultural area due to their capacity to absorb and release water and the potential to simultaneously release agrochemicals in a controlled manner, which must occur under a sustainable and environmentally friendly approach. In this sense, hydrogels based on biomolecules emerge as one of the most appropriate and relevant alternatives to achieve these objectives; being the starch one of the most investigated polysaccharides for obtaining hydrogels through physical and chemical crosslinking strategies Chemical crosslinking refers to the formation of hydrogels through chemical reactions that lead to the generation of covalent bonds between the polymeric chains generating the three-dimensional system (Palencia et al, 2021). This is the case of the hydrogels obtained by Savitri and collaborators, who synthesized a hydrogel based on starch and chitosan through chemical crosslinking between the hydroxyl functional group of starch and the amino functional group of chitosan, for the controlled release of phosphorus, where the ideal starch-chitosan ratio was 30:70 with a decrease in the loss of fertilizer over time (Qiao et al, 2016).…”

“…(Chen et al, 2020; Chiaregato and Faez, 2021; Ibrahim et al, 2019; Junlapong et al, 2020; Motamedi et al, 2020; Qiao et al, 2016; Salimi et al, 2020; Sarkar et al, 2021).Physical crosslinking is based on the formation of the hydrogel through physical interactions, like electrostatic, hydrogen bonds, or non-covalent crosslinking between the polymeric chains(Palencia et al, 2021). An example of this last alternative is the research carried out by Vudjung and collaborators, who developed biodegradable hydrogels based on interpenetrating polymeric networks generated from cassava starch, sulfur, glutaraldehyde, and pre-vulcanized natural rubber that allowed water absorption and controlled release of urea nitrogen fertilizers; finding that, the higher the starch content, the higher the water absorption capacity and the permeability(Vudjung and Saengsuwan, 2018).…”

Gels, Aerogels and Hydrogels: A Challenge for the Cellulose-Based Product Industries

“…Thus, the physical and chemical characteristics of the gels are adjusted through the modification of functional groups. The presence of functional groups on the cellulose backbone can be characterized easily by ultra-violet-visible spectroscopy, nuclear magnetic resonance, infrared spectrophotometry and mass spectrophotometry [ 27 ].…”