Novel approach to promote the hydrophobic association: Introduction of short alkyl chains into hydrophobically associating polyelectrolytes

Abstract

A novel approach to promote hydrophobic association by incorporating short alkyl chains onto polyelectrolytes (HAPEs) was presented. A series of HAPEs was synthesized by free radical copolymerization in aqueous media with acrylamide (AM), 11-acrylamidoundecanoic acid (C 11 AM), and 6-acrylamidohexanoic acid (C 6 AM). The structures and compositions of the polymers were confirmed by 1 H-NMR, and the molecular weights were determined by GPC. Results of rheological experiments revealed that viscosities increased greatly in samples containing C 11 AM and C 6 AM compared with the sample without C 6 AM. The sample without C 6 AM was also characterized by critical association concentrations and critical angular frequencies. Solubilization and bridging interaction were considered as the possible reasons. Pyrene fluorescence probe data and 1 H-NMR spin-spin relaxation times further illustrated the reinforcement of hydrophobic associations by short alkyl side chains. All the results showed that the optimum content of C 6 AM was 1 mol % in the prepared HAPEs.

Preparation and performance evaluation of hydrophobically associating polymer anti‐water channeling agent for oil well cement

“…This shows that the hydration products of cement slurry with hydrophobic polymer SMAL are basically not affected by water invasion, which improves the anti-water channeling ability of cement slurry and ensures the structural integrity of cement stone. 39,40 In summary, the above results indicate that SMAL enhances the water invasion resistance of the cement slurry during cementing under dynamic pressure, thus improving the anti-fluid channeling ability of the cement stone.…”

“…In addition, the needle‐stick AFt crystals are clearly visible. This shows that the hydration products of cement slurry with hydrophobic polymer SMAL are basically not affected by water invasion, which improves the anti‐water channeling ability of cement slurry and ensures the structural integrity of cement stone 39,40 …”

Hydrogel: Diversity of Structures and Applications in Food Science

“…[178,179] Approaches including those related to the molecular weights, distribution sequence of the hydrophobic groups, type, and content of the hydrophobic groups, type and content of the ionic groups, and relative positions of the hydrophobic and ionic groups can be adopted to improve the hydrophobic association ability of HAPEs and HAPs. [180][181][182][183][184] When the concentration of the hydrophobic monomer was above the critical micellar concentration (CMC), the hydrophobic monomers formed stable hydrophobic association domains in the presence of a surfactant. Meanwhile, intermolecular hydrophobic interactions or micro-block copolymerization lead to the formation of a three-dimensional network of polymer chains, resulting in a rapid increase in the apparent viscosity, [178] in which the mixed micelles of the hydrophobic groups and surfactants would act as crosslinking points [179,185] (Fig.…”

Current Research on Polyelectrolyte Nanostructures: From Molecular Interactions to Biomedical Applications

“…This kind of NP allows for the solubilization of hydrophobic molecules, e.g., drugs, in their core while the external shell not only stabilizes them in aqueous media [31,32] but also can bind oppositely charged molecules, e.g., proteins [33][34][35]. On the other hand, random amphiphilic copolymers of polyelectrolyte and hydrophobic monomers, the so called hydrophobically-associating polyelectrolytes, are able to tune viscoelastic properties in aqueous media via a balance between electrostatic repulsions and hydrophobic associative attractions [36,37]. Except from the response to the pH and salt stimuli, polyelectrolyte-containing copolymers can response to the temperature of the solution by the incorporation of thermo-responsive blocks, the most often used being poly(N-isopropylacrylamide) (PNIPAM) [38].…”