Association Behaviors of Dodecyltrimethylammonium Bromide with Double Hydrophilic Block Co-polymer Poly(ethylene glycol)-block-Poly(glutamate sodium)

Abstract

The association behaviors of single-chain surfactant dodecyltrimethylammonium bromide (DTAB) with double hydrophilic block co-polymers poly(ethylene glycol)-b-poly(sodium glutamate) (PEG(113)-PGlu(50) or PEG(113)-PGlu(100)) were investigated using isothermal titration microcalorimetry, cryogenic transmission electron microscopy, circular dichroism, ζ potential, and particle size measurements. The electrostatic interaction between DTAB and the oppositely charged carboxylate groups of PEG-PGlu induces the formation of super-amphiphiles, which further self-assemble into ordered aggregates. Dependent upon the charge ratios between DTAB and the glutamic acid residue of the co-polymer, the mixture solutions can change from transparent to opalescent without precipitation. Dependent upon the chain length of the PGlu block, the mixture of DTAB and PEG-PGlu diblocks can form two different aggregates at their corresponding electroneutral point. Spherical and rod-like aggregates are formed in the PEG(113)-PGlu(50)/DTAB mixture, while the vesicular aggregates are observed in the PEG(113)-PGlu(100)/DTAB mixture solution. Because the PEG(113)-PGlu(100)/DTAB super-amphiphile has more hydrophobic components than that of the PEG(113)-PGlu(50)/DTAB super-amphiphile, the former prefers forming the ordered aggregates with higher curvature, such as spherical and rod aggregates, but the latter prefers forming vesicular aggregates with lower curvature.

Assembly and Reassembly of Polyelectrolyte Complex Formed by Poly(ethylene glycol)-block-poly(glutamate sodium) and S5R4 Peptide

“…PEG 114 -PGlu 64 diblock was synthesized by ring-opening polymerization of Lbenzylglutamate N-carboyxanhydride (BLG-NCA) by following a reported procedure. 36 The number-averaged molecular weight and molecular weight distribution were characterized using gel permeation chromatography (GPC)/laser light scattering (LLS) with DMF containing 0.2 M LiBr as the eluent. The polydispersity index (PDI) value is about 1.2.…”

Constructing Gemini‐Like Surfactants with Single‐Chain Surfactant and Dicarboxylic Acid Sodium Salts

“…ITC measurement has been extensively applied in the study of the association behaviors and intermolecular interactions of surfactant molecules with other compounds [29][30][31][32][33][34][35]. In this work ITC is used to investigate the intermolecular interactions between CTAB and C n Na 2 .…”

Thermodynamic Association Behaviors of Sodium Dodecyl Sulfate (SDS) with Poly(4‐vinylpyridine N‐oxide) (PVPNO) at Different pH Values and Ionic Strengths

“…In oppositely charged polymer/surfactant systems, surfactant molecules with opposite charge can adsorb strongly onto the polyelectrolyte chain to form insoluble complexes in water [1][2][3][4][5][6]. Electrostatic factors, including micelle surface charge density, polymer linear charge density, and ionic strength play a dominant role in complex formation between oppositely charged polyelectrolyte and surfactant [7][8][9][10][11].…”