Aggregation behavior of non-cytotoxic ester functionalized morpholinium based ionic liquids in aqueous media

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Toxicology

Background:

• Ionic liquids (ILs) are salts with low melting points, offering unique properties.
• Surface-active ionic liquids (SAILs) combine IL characteristics with surfactant behavior.
• Functionalization of SAILs can tune their properties for specific applications.

Purpose of the Study:

• Synthesize and characterize novel ester-functionalized SAILs ([CnEMorph][Br]).
• Investigate the aggregation behavior and interfacial properties of these SAILs.
• Evaluate the cytotoxicity of the synthesized SAILs for potential biological applications.

Main Methods:

• Synthesis of N-methylmorpholine-based SAILs with varying alkyl chain lengths (n=8, 12, 16).
• Characterization using tensiometry, conductometry, isothermal titration calorimetry (ITC), spectrofluorometry, dynamic light scattering (DLS), and atomic force microscopy (AFM).
• Thermal stability assessed by thermogravimetric analysis (TGA); cytotoxicity evaluated using MTT assay on C6 glioma cells.

Main Results:

• SAILs demonstrated lower critical aggregation concentrations (cac) and enhanced adsorption at the air-solution interface compared to conventional surfactants.
• Aggregation properties were found to be dependent on the alkyl chain length.
• Synthesized SAILs exhibited non-cytotoxic behavior within relevant concentration ranges.

Conclusions:

• Ester-functionalized SAILs present superior interfacial activity and favorable aggregation behavior.
• These SAILs are non-cytotoxic, indicating their potential for biological and other applications.
• Alkyl chain length is a key factor in controlling the aggregation characteristics of these novel SAILs.