There is an urgent requirement to devise and develop highly-effective materials for the purification of industrial wastewater. Coloured effluents are particularly problematic due to their toxicity in plants, aquatic organisms and animals, dictating that polymeric adsorbents are highly sought for their capture.Chitosan hydrogels are a cost-effective substrate for the adsorption of dye molecules as they are contain a biopolymeric gelator that can form hydrogels with a polymer content as low as 3% by mass. Such materials are also highly suited for use within a biomedical context as carrier vehicles for the encapsulation and delivery of protein macromolecules, due to their hydrophilic nature. We disclose the capability chitosan-based hydrogels to non-covalently adsorb both reactive and disperse dye molecules, and a model anionic protein from aqueous solution. The materials generated offer both a platform for dye removal from industrial wastewater, and for the encapsulation and pH-mediated release of protein macromolecules.

Amphiphilic block copolymers have been developed for the encapsulation of silver anticancer drugs.

The deposition of dyes onto lightly colored garments, or onto lighter sections of multicolored garments, during laundry results in fabric discoloration. In particular, there is a requirement to restrict indigo dye transfer between garments. Polymers may be added to detergent formulations as dye transfer inhibitors to prevent dye transfer by blocking the deposition of fugitive dyes in aqueous solution. This article reports the generation of a range of dye transfer inhibitors produced by condensation reactions that are effective in preventing the transfer of unbound indigo dye to a variety of fiber types. Key design rules relating to polymer hydrophilicity and pendant polymer functionality were established for the creation of effective dye transfer inhibitors. Remarkably, polymers at concentrations as low as 0.1 mg/ml were found to be effective in inhibiting indigo deposition on a variety of fiber types, offering great promise for their inclusion within laundry detergent formulations as dye transfer inhibitors.