LAUSR

Abstract To further investigate the interaction between surface-modified nanoparticles and wormlike micelles (WLMs) and their rheological response, a newly kind of anhydride-modified silica nanoparticles (AMSNPs) was modified by succinic anhydride. A quaternary ammonium surfactant with the headgroup modified by two hydroxyethyl groups N-cetyl-N,N-di(2-hydroxyethyl)methylammonium bromide (CDHAB) was synthesized in this work. The transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and dynamic light scattering (DLS) were used to characterize AMSNPs. The formation of WLMs by CDHAB and sodium salicylate (NaSal) was observed by cryogenic transmission electron microscopy (cryo-TEM). With the addition of nanoparticles, rheological properties of WLM solution get enhancement remarkably. Furthermore, compared with the aid of normal silica nanoparticles (SNPs), WLMs with AMSNPs show higher viscosity and better viscoelasticity. This can be attributed to the high ionization degree of AMSNPs in the nanofluid and stronger electrostatic attraction and extra hydrogen bonding interaction between functional groups of AMSNPs and CDHAB, leading to more micelle-nanoparticle junctions and longer micelles. This work can give further view and knowledge of interaction between functional groups of modified nanoparticles and special surfactants of WLMs.