Micro-mechanism insights into the adsorption of anionic dyes using quaternary ammonium-functionalised chitosan aerogels

Adsorption of cationic/anionic dyes and endocrine disruptors by yeast/cyclodextrin polymer composites

“…This is attributed to electrostatic interactions and other interactions that synergistically enhance the adsorption of MO by IBY-PA-CDP, such as van der Waals forces, hydrophobic interactions, hydrogen bonding, and host–guest interactions. 46 Interestingly, the MO adsorption capacity of IBY increased as the pH increased from 2 to 3. This may be because a more acidic solution altered the structure of the polymer on the IBY surface.…”

Comb-Like Cationic Chitosan-Based Flocculant with Enhanced H-Bond Hydration for Effectively Treating Saline Colored Effluents with High Salinity

“…Flocculation exhibits remarkable advantages in the treatment of large-scale wastewater due to its simplicity, cost-effectiveness, and applicability to both dissolved and insoluble pollutants. − However, recent research − has shown that commonly used flocculants such as inorganic flocculants like polyaluminum chloride and synthetic organic flocculants like polyacrylamide are toxic to human beings and the environment and have become a new source of secondary pollution due to leakage of metal ions and unreacted monomer residues during flocculant preparation and application. In contrast, natural biopolymer-derived flocculants such as chitosan (CS) offer an excellent solution to the aforementioned toxicity problem. − CS is one of the most abundant natural polymers with the advantages of environmentally friendliness, biodegradability, and high performance, and it has been widely explored for treating a wide variety of stimulated and real wastewater. − It possesses abundant amino and hydroxyl functional groups on its backbones, allowing it to be modified by various chemical reactions such as amidation, carboxymethylation, and quaternization. ,− Du et al fabricated a quaternized CS (QCS)-based aerogel with outstanding adsorption capacities, wide versatility, and excellent recyclability for organic dyes. Liu et al successfully prepared a modified CS flocculant, CTS-DAC-AMPS, by introducing acryloyloxyethyl trimethylammonium chloride and 2-acrylamido-2-methylpropanesulfonic acid into the amino group of CS, which was superior to that of the commercially available flocculants in the treatment of industrial wastewater.…”

Self-Assembly of Cinnamic Acid-Modified Chitosan Surfactants: Synthesis, Characterization, and Applications in Emulsification

“…have been synthesized for emulsification, adsorption, coating, and oil extraction due to their advantages of safety, biodegradability, and wide sources. − For instance, peanut protein isolate was used as an emulsifier to develop high internal phase emulsion . The synthesized vinyl inulin with self-assembly and emulsifying properties was used to encapsulate hydrophobic compounds. , Ammonium-functionalized chitosan aerogel was applied to adsorb anionic dyes . Among these natural substances, chitosan-derived surfactants have the widest application range, covering emulsification, oil extraction, dye adsorption, and oil–water separation .…”

“…Among these natural substances, chitosan-derived surfactants have the widest application range, covering emulsification, oil extraction, dye adsorption, and oil–water separation . More importantly, the positive electrical properties and antibacterial activity of chitosan make its derived surfactants superior in food, pharmaceutical products, and anionic dye adsorption. ,− Chitosan derivatives that retain positive electrical properties could form more stable colloidal products due to electrostatic interactions. − The antibacterial activity enables these derivatives to excel in killing pests, preventing food spoilage, and accelerating infected wound healing. − For example, cinnamic acid-grafted chitosan nanogel was reported to be able to embed hydrophobic substances and exhibit excellent antifungal activity . However, these reported chitosan-derived surfactants either had a single function, were toxic and harmful, or lacked mechanisms and safety evaluations, making it difficult to generalize and be widely applied in different fields.…”