Langmuir Film of Poly(ethylene oxide) at Air–Water Interface Using Water as Solvent

• Published in: Industrial & engineering chemistry research 2019-05, Vol.58 (18), p.7489-7494
• Main Authors: Bhande, Ramesh S, Mohite, Lalaso V, Juvekar, Vinay A
• Format: Article
• Language: English
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/acs.iecr.8b04805

A Langmuir film of poly­(ethylene oxide) (PEO) has been prepared at the air–water interface using water as the spreading solvent. Unlike the conventional PEO film (prepared using chloroform as the solvent), which exhibits the highest surface pressure of 10 mN/m, the present film attains a surface pressure of 17.5 mN/m at high apparent polymer loading (35 mg/m2).The π–A isotherm of a film prepared at low PEO loading was observed to be similar in nature to the conventional isotherm of PEO, and the surface pressure attained for the film is 10.5 mN/m at a loading of 1 mg/m2. The key step in the preparation of the film is to use a higher initial loading of polymer and multiple compression–expansion cycles to induce aggregation and compaction of PEO molecules in the film. The prepared Langmuir films were characterized in term of surface pressure–surface area isotherms, the hysteresis exhibited by these isotherms, and the static dilatational modulus.