Trimeric Cationic Surfactant Coacervation as a Versatile Approach for Removing Organic Pollutants

Abstract

A versatile method to remove a broad spectrum of dye pollutants from wastewater rapidly and efficiently is highly desirable. Here, we report that the complex coacervation of cationic trimeric imine-based surfactants (TISn) with negatively charged hydrolyzed polyacrylamide (HPAM) can be used for this purpose. The coacervation occurs in a wide concentration and composition range and requires the HPAM and TISn concentrations as low as 0.1 g/L and 0.1 mM, respectively. Dye effluents treated by trimeric surfactants and HPAM complete phase separation within 30 s under turbulent conditions, which generates an exceedingly small volume fraction (0.4%) of viscoelastic coacervate and a clear supernatant with a dye removal efficiency of up to 99.9% for anionic and neutral dyes in dosages of up to 120 mg/L. Crowded molecular arrangement and thick framework in coacervate are responsible for the rapid phase separation rate and low volume fraction. The trimeric imine surfactant/polymer coacervation provides a simple, effective, and sustainable approach for the rapid removal of dyes and other organic pollutants.

Deposition and Spread of Aqueous Pesticide Droplets on Hydrophobic/Superhydrophobic Surfaces by Fast Aggregation of Surfactants

“…Meanwhile, the stronger binding ability of coacervates with water is beneficial for the coacervate to bind with various specific polar microregions at superhydrophobic leaf surfaces and helpful for the surface wettability transition from superhydrophobic to hydrophilic. More specifically, the nanosized network microstructure of coacervates leads to effective encapsulation for a broad range of hydrophilic and hydrophobic solutes as well as the responsive ability to the environment. , These comprehensive features endow the coacervates with more superior properties as pesticide carriers, making sprayed droplets completely deposit and spread and enhancing agrochemical solubilization, stability, and control release. Even more, the entanglement of network-like microstructure with the micro/nanostructures of superhydrophobic surfaces effectively inhibit the wind/rainwater erosion of the droplets after deposition, and the imine groups in the dynamic covalent surfactant endow the coacervate dissociation with CO 2 responsiveness; so, the release of pesticides is controlled by CO 2 in air.…”

Encapsulation behavior of curcumin in heteroprotein complex coacervates and precipitates fabricated from β-conglycinin and lysozyme

“…6), enclosing the curcumin of the entire mixed system. It was reported that hydrophilic dyes could also be well encapsulated in the coacervate compartment and some studies utilized the adsorptive network structure of coacervates as a general method for removing and recovering dyes from wastewater (Liu, Zhao, Shen, Fan, & Wang, 2021;Meng, Schiffman, & Perry, 2018;Shah et al, 2020). Coacervation also played role in biological cells as physicochemical and mechanical filters of pore-like structures, such as nuclear pores (Schmidt & Görlich, 2016).…”

Interfacial stabilization of aqueous two-phase systems: a review

“…on the composition and properties of the coacervate and supernatant phases has emerged. 93 The crowded interiors of the coacervates and their ability to sequester charged (bio)macromolecules from their surroundings have promoted their utility as encapsulants and stabilizers in biological, 79,94 industrial, 95–97 environmental, 17,19,83 and cosmetic applications. 81,82…”