Structural investigation of viscoelastic micellar water/CTAB/NaNO3 solutions

Pramana

P Bahadur1²  L Abezgauz¹  D Varade³  K Kuperkar²  V K Aswal⁴  P A Hassan⁴  D Danino¹  G Verma⁴ 

[1] Technion, Haifa, Israel$$;Department of Chemistry, Veer Narmad South Gujarat University, Udhna-Magdall Road, Surat 395 007, India$$;Yokohama National University, Yokohama, Japan$$;Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India$$

关键词: Worm-like micelles;    viscoelasticity;    small angle neutron scattering;    cryo-TEM.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

A highly viscoelastic worm-like micellar solution is formed in hexa-decyltrimethylammonium bromide (CTAB) in the presence of sodium nitrate (NaNO3). A gradual increase in micellar length with increasing NaNO3 was assumed from the rheological measurements where the zero-shear viscosity (𝜂0) versus NaNO3 concentration curve exhibits a maximum. However, upon increase in temperature, the viscosity decreases. Changes in the structural parameters of the micelles with addition of NaNO3 were inferred from small angle neutron scattering measurements (SANS). The intensity of scattered neutrons in the low 𝑞 region was found to increase with increasing NaNO3 concentration. This suggests an increase in the size of the micelles and/or decrease of intermicellar interaction with increasing salt concentration. Analysis of the SANS data using prolate ellipsoidal structure and Yukawa form of interaction potential between mi-celles indicate that addition of NaNO3 leads to a decrease in the surface charge of the ellipsoidal micelles which induces micellar growth. Cryo-TEM measurements support the presence of thread-like micelles in CTAB and NaNO3.

【 授权许可】

Unknown