Big effects of small nanoparticles on hydrophobically modified polyacrylamide in an aqueous solution

Abstract

In this study, we investigated the self‐assembly properties of small‐sized (3–5 nm) oppositely charged SiO2 nanoparticles (NPs) and hydrophobically modified polyacrylamide (hm‐PAM) in aqueous solutions by rheological and structural analysis. The results show that the addition of small NPs to the hm‐PAM solution remarkably enhanced its viscosity and viscoelasticity, and the viscosity remained high at elevated temperatures. Specifically, the low shear rate viscosity of the NP–hm‐PAM solutions increased by up to three orders of magnitude at a very low loading of NPs (10−2 wt %). Moreover, there appeared to be no sediment in the dispersed system after over 18 months of storage. Scanning electron microscopy and transmission electron microscopy measurements indicated that additional physical crosslinks were formed after the addition of the small silica NPs to the hm‐PAM solutions. With the experiments and published results combined, we proposed a simple model of electrostatic and hydrophobic interactions for the crosslinking structure of the NP–hm‐PAM composite. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47269.

Polymer viscosifier systems with potential application for enhanced oil recovery: a review

“…They also found that the CAC of XG-C16 was 1600 ppm, and starting at this concentration, there was a significant increase in the viscosity of the solution, indicating the association of the hydrophobic groups of the modified polymer. Peng et al (2019) studied the effect of adding silica nanoparticles in hydrophobically modified polyacrylamide with N, N-dimethyl octadecyl ammonium groups (NP-HMAP) and found that the presence of silica improved the viscosity and viscoelasticity of the polymeric solution at high temperatures. Thus, the addition of nanofillers was cited as a way to further improve the properties of hydrophobically modified polymers.…”

Rheology of Triamine Functionalized Silica Reinforced Polymeric Gels Developed for Conformance Control Applications

“…Moreover, it has a high surface area which is beneficial in providing a more stable structure through increasing the tie points between the polymer entanglement . Nanosilica increases the long-term stability of the modified hydrophobic PAM to more than 18 months . Increasing the temperature enhances the adsorption of PAM on the silica surface .…”

“…14 Nanosilica increases the long-term stability of the modified hydrophobic PAM to more than 18 months. 15 Increasing the temperature enhances the adsorption of PAM on the silica surface. 16 Nonfunctionalized silica contains a silanol group, and other types of materials such as sodium silicate have been used as reinforcement agents.…”