Copolymer based on lauryl methacrylate and poly(ethylene glycol) methyl ether methacrylate as amphiphilic macrosurfactant: Synthesis, characterization and their application as dispersing agent for carbon nanotubes

Abstract

The use of amphiphilic macrosurfactants as emulsifying agents has shown to have higher efficiency than that of low molecular weight surfactants. Compared to traditional surfactants, polymeric surfactants have lower critical micelle concentrations and lower diffusion coefficients. In this paper, we present a well defined copolymer based on lauryl methacrylate and poly(ethylene glycol) methyl ether methacrylate, prepared by solution radical copolymerization. The product was characterized by NMR and FTIR spectroscopies and the weight-average molecular weight and polydispersity index were analyzed by SEC. The thermal transitions and decomposition temperatures of the copolymers were determined by DSC and TGA, respectively. Due to the hydrophobic and hydrophilic nature of the monomer units, emulsification studies were performed. DLS experiments showed different sizes of the formed micelles depending on solvent polarity due to polymer-polymer or polymer-solvent interactions. Rheological characterization was undertaken to study the viscoelastic properties of the dispersed systems. Finally, two types of experiments to evaluate the polymer abilities as surfactant have been carried out. Firstly, the amphiphilic characteristics of this material allowed the incorporation of small amounts of an organic solvent in water forming only one phase, as well as the incorporation of small amounts of water in the organic solvent forming an emulsified phase. Then, the amphiphilic properties of this macrosurfactant have been fully exploited in order to form highly stable dispersions of carbon nanotubes in water.

Amphiphilic Poly[poly(ethylene glycol) methacrylate]s with OH Groups in the PEG Side Chains for Controlling Solution/Rheological Properties and toward Bioapplication

“…The intermolecular hydrogen bonding gradually weakened with an increasing shear rate. In addition, both shear stress and viscosity discontinuously decreased at around 100 s –1 , indicating that the aggregate structure in the bulk state collapsed . The shear viscosity of P33 decreased over 150 s –1 because the star–star interaction decreased with an increasing shear rate.…”

“…The viscoelastic properties of PEGOHMA-based copolymers were characterized using a rheometer − to investigate the effects of the OH groups on the PEG side chains and the primary structure. We selected three types of polymers, poly­(PEG4.5MA) 25 ( P2 ), poly­(PEG4.5OHMA) 25 ( P12 ), and a star polymer ( P33 ).…”

Structure and dynamics of liposomes designed for drug delivery: coarse-grained molecular dynamics simulations to reveal the role of lipopolymer incorporation

“…Furthermore, it should be noted that, for a macroscale viewpoint where the liposomes can be viewed as dispersed colloidal microspheres, the polymer plays an important role in preventing the liposomes aggregation and in facilitating their transport ( Table 5 ). 63 …”

“…viewed as dispersed colloidal microspheres, the polymer plays an important role in preventing the liposomes aggregation and in facilitating their transport (Table 5). 63…”

Preparation of Hydrophilic Encapsulated Carbon Nanotubes with Polymer Brushes and Its Application in Composite Hydrogels

“…In order to enhance the hydrophilicity of CNTs, hydrophilic groups, such as OH and COOH, can be introduced by treating CNTs with concentrated sulfuric acid and nitric acid, however, the intrinsic structure of the CNTs is usually damaged during the reaction process. On the other hand, amphiphilic polymers can be used to prepare hydrophilic CNTs by wrapping CNTs with polymers based on the noncovalent interactions between CNTs and polymers, such as hydrophilic–hydrophobic interaction and π–π stacking. , Recently, micelle-encapsulated CNTs were prepared by using small molecular surfactants, ,,,, or amphiphilic polymers, − and could be homogeneously dispersed in aqueous solution. This encapsulation method can avoid significant damage and retain the structural integrity of the CNTs, and achieve a homogeneous dispersion of hydrophilic CNTs.…”