Interfacial Properties of Methylcelluloses: The Influence of Molar Mass

Polymers

Pauline L. Nasatto³  Frຝéric Pignon²  Joana L. M. Silveira³  Maria Eugênia R. Duarte³  Miguel D. Noseda³  Marguerite Rinaudo¹ 

[1] Biomaterials Applications, 6, rue Lesdiguières, F-38000 Grenoble, France; E-Mail:;Laboratoire rhéologie et procédés (LRP), University Grenoble Alpes, F-38000 Grenoble, France; E-Mail:;Departamento de Bioquímica e Biologia Molecular, Federal University of Paraná, P.O. Box 19046, CEP 81531-980, Curitiba, Paraná, Brazil; E-Mails:

关键词: surface tension;    adsorption;    electrokinetic potential;    methylcellulose;    molar mass influence;    silica particles;   

DOI  :  10.3390/polym6122961

来源: mdpi

【 摘 要 】

The interfacial interactions of four methylcelluloses having the same average degree of substitution and distribution of methyl groups, but different molar masses, are studied at ambient temperature and at very low polymer concentrations. Firstly, the surface tension σ at the water/air interface is determined for the progressive addition of methylcellulose up to 100 mg/L; σ starts to decrease over 1 mg/L up to the critical aggregation concentration (CAC) at 10 mg/L. The curves describing the influence of polymer concentration on σ are independent of the molar mass at equilibrium. Secondly, the adsorption of methylcellulose on silica particles is estimated from ζ-potential measurements. The data are interpreted in terms of an increase of the adsorbed layer thickness at the interface when the molar mass of methylcellulose increases. It is concluded that methylcellulose is adsorbed, forming trains and loops at the interface based on the equilibrium between surface free energy and solvent quality.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.