Thermoresponsive Reversible Behavior of Multistimuli Pluronic-Based Pentablock Copolymer at the Air−Water Interface

Abstract

Surface behavior of the pH-and thermoresponsive amphiphilic ABCBA pentablock copolymer has been studied with respect to the environmental conditions. We demonstrate that the pentablock copolymer poly((diethylaminoethyl methacrylate)-b-(ethylene oxide)-b-(propylene oxide)-b-(ethylene oxide)-b-(diethylaminoethyl methacrylate)) possesses reversible temperature changes at the air-water interface in a narrow pH range of the water subphase. Significant diversity in the surface morphology of pentablock copolymer monolayers at different pH and temperatures observed were related to the corresponding reorganization of central and terminal blocks. Remarkable reversible variations of the surface pressure observed for the Langmuir monolayers at pH 7.4 in the course of heating and cooling between 27 and 50°C is associated with conformational transformations of terminal blocks crossing the phase line in the vicinity of the lower critical solution temperature point. The observed thermoresponsive surface behavior can be exploited for modeling of the corresponding behavior of pentablock copolymers adsorbed onto various biointerfaces for intracellular delivery for deeper understanding of stimuli-responsive transformations relevant to controlled drug and biomolecules release and retention. Surface behavior of the pH-and thermoresponsive amphiphilic ABCBA pentablock copolymer has been studied with respect to the environmental conditions. We demonstrate that the pentablock copolymer poly((diethylaminoethyl methacrylate)-b-(ethylene oxide)-b-(propylene oxide)-b-(ethylene oxide)-b-(diethylaminoethyl methacrylate)) possesses reversible temperature changes at the air-water interface in a narrow pH range of the water subphase. Significant diversity in the surface morphology of pentablock copolymer monolayers at different pH and temperatures observed were related to the corresponding reorganization of central and terminal blocks. Remarkable reversible variations of the surface pressure observed for the Langmuir monolayers at pH 7.4 in the course of heating and cooling between 27 and 50°C is associated with conformational transformations of terminal blocks crossing the phase line in the vicinity of the lower critical solution temperature point. The observed thermoresponsive surface behavior can be exploited for modeling of the corresponding behavior of pentablock copolymers adsorbed onto various biointerfaces for intracellular delivery for deeper understanding of stimuli-responsive transformations relevant to controlled drug and biomolecules release and retention.

Bimaterial Microcantilevers as a Hybrid Sensing Platform

“…[30,31] Thin polymer films and patterned surface layers from PNIPAM-based materials and some other blockcopolymers show switchable adhesive and mechanical properties. [32][33][34] For amphiphilic block copolymers, hydrophobic effect causes different blocks to aggregate and form micelles in aqueous medium. There are several examples demonstrating the structural changes in these polymer micelles under varying pH and temperature.…”

pH induced tuning of size, charge and viscoelastic behavior of aqueous micellar solution of Pluronic ® P104–anthranilic acid mixtures: A scattering, rheology and NMR study

“…The presence of various additives such as electrolytes [10,11], non-electrolytes [12,13], hydrotropes [14], surfactants [15,16], ionic liquids [17] other water soluble polymers [7,18] can alter the self-assembling characteristics such as surface activity [19], and micellar characteristics [20][21][22]. There are also reports of tuning aggregate characteristics of Pluronics ® using end group functionalized block copolymers [9,23]. By modulating the phase behavior [24] of Pluronics ® using other additives, properties can be tuned to performance based applications.…”

Synthesis and self-assembly behavior of six-armed block copolymers with pH- and thermo-responsive properties

“…Since the tertiary amine pendent groups were partially deprotonated when the pH reached slightly above the pK a of PDEAEMA, the effect of temperature and pH on D h was dominant. 37 Initially, the D h decreased mildly from 25 to 29 o C due to the dehydration of PDE-AEMA. With increasing temperature above 30 o C, the size of aggregates became much larger because of the further aggregation in order and the PDI decreased.…”