Photoinduced post-modification of graphitic carbon nitride-embedded hydrogels: synthesis of 'hydrophobic hydrogels' and pore substructuring

Abstract

Hydrogels are a special class of crosslinked hydrophilic polymers with a high water content through their porous structures. Post-modifications of hydrogels propose an attractive platform so that a variety of fresh functions, which are not arising from initial monomers, could be accessible on a parental network. Photoinduced post-modification of hydrogels by embedding semiconductor nanosheets would be of high interest and novelty. Here, a metal-free semiconductor graphitic carbon nitride (g-CN)-embedded hydrogel as an initial network was synthesized via redox-couple initiation under dark conditions. Post-photomodification of so-formed hydrogel, thanks to the photoactivity of the embedded g-CN nanosheets, was exemplified in two scenarios. The synthesis of ‘hydrophobic hydrogel’ is reported and its application in delayed cation delivery was investigated. Furthermore, pores of the initial hydrogel were modified by the formation of a secondary polymer network. Such a facile and straightforward synthetic protocol to manufacture functional soft materials will be of high interest in near future by the means of catalysis and agricultural delivery.

Photocatalyst-Incorporated Cross-Linked Porous Polymer Networks

“…In addition to "hydrophobic hydrogel" fabrication, parental g-CN embedded hydrogel is swollen by various acrylate monomers via immersion, and, under visible-light irradiation, secondary polymer networks were formed, resulting in "pore substructuring". 88 CO 2 can help forming porosity in macroscale structures, as shown in fabrication of g-CN-immobilized alginate porous gel beads. Aqueous dispersion of g-CN nanosheets (CNNSs) were mixed with sodium alginate (NaAlg) solution containing sodium dodecyl sulfate (SDS) and sodium bicarbonate (NaHCO 3 ) under agitation until a foamy solution is obtained.…”

“…It is demonstrated that resulting “hydrophobic hydrogel” can be employed for agricultural applications to simulate a nutrition release system in a controlled way. In addition to “hydrophobic hydrogel” fabrication, parental g-CN embedded hydrogel is swollen by various acrylate monomers via immersion, and, under visible-light irradiation, secondary polymer networks were formed, resulting in “pore substructuring” …”

Multicompartment Hydrogels

“…[19,20] The present review deals with another way to change the properties of hydrogels apart from type of bonding, shape, and mechanical properties, namely, via composition. A variation of composition can be introduced via functionalization (also with spatial control), [21,22] for example, but also by introduction of compartments. The variation of hydrogel composition puts hydrogels on a new level of complexity giving rise to novel applications and tuning of hydrogel properties.…”

Light-Driven Integration of Graphitic Carbon Nitride into Polymer Materials

“…Scheme 2. Schematic overview of g-C 3 N 4 -embedded hydrogel fabrication and its subsequent photoinduced post-modifications[8]. Copyright 2021, Beilstein Journal of Organic Chemistry.…”