A Review on Hydrophobically Associated Alginates: Approaches and Applications

Area of Science:

• Biopolymers and Materials Science
• Polymer Chemistry
• Chemical Engineering

Background:

• Alginates are hydrophilic, anionic polysaccharides with biocompatible, nontoxic, and biodegradable properties.
• Their structure, composed of D-mannuronic acid (M) and L-guluronic acid (G) units, features abundant hydroxyl and carboxyl groups.
• Current applications in food and pharmaceuticals primarily utilize alginates as gelling and thickening agents.

Purpose of the Study:

• To review chemical modifications for imparting hydrophobicity to alginates.
• To highlight methods for creating hydrophobically modified alginates.
• To discuss the broad applications of these modified alginates.

Main Methods:

• Chemical modifications including esterification, Ugi reaction, reductive amination, and graft copolymerization are employed.
• These methods introduce hydrophobic characteristics to the hydrophilic alginate backbone.
• The review synthesizes existing literature on these modification techniques.

Main Results:

• Hydrophobic modification increases alginates' affinity for hydrophobic substances, enabling sustained release of drugs and pesticides.
• Modified alginates serve as effective emulsion stabilizers in the food industry, improving oil-in-water emulsions and creaming.
• Functionalization of alginate-based materials like membranes, aerogels, and films enhances their utility in water treatment and food packaging.

Conclusions:

• Hydrophobically modified alginates offer expanded applications beyond traditional uses.
• These modifications are crucial for developing advanced materials in drug delivery, food science, and environmental technology.
• Further research into alginate hydrophobicity holds potential for novel material development.