Oxidative degradation of triblock-copolymer surfactant and its effects on self-assembly

Abstract

We investigate the degradation behaviour of a triblock-copolymer surfactant made from polyethylene oxide (PEO) and polypropylene oxide (PPO) (PEO-PPO-PEO), highlighting how the aggregation behaviour of this polymer in water alters with ageing. Samples aged at room temperature were compared to samples degraded using accelerated ageing at elevated temperatures. We find that large mass losses occurred to the polymer surfactant which resulted in a change in the aggregation behaviour, with larger, rod-like or planar aggregates forming at longer degradation times. We look at how this change in aggregation behaviour changes the formulation stability of these polymers, specifically, the interaction of the polymer surfactant with poly(N-isopropylacrylamide) microgels. It is known that these species associate and form gels at elevated temperatures. This paper highlights how commonly used polymeric surfactants can degrade over time, resulting in dramatic changes to aggregation behaviour and therefore, formulation properties.

Properties and molecular self‐assembly of liquid crystalline hard–hard diblock and hard–soft–hard triblock copolymers influenced by Flory–Huggins interaction parameter and volume fraction of distinct segments

“…Especially, the ABC-type triblock copolymers having two composition variables and three interaction parameters which make their microphase behaviors much more complicated than the ABtype diblock copolymers with only one composition variable and one interaction parameter. [19][20][21][22][23][24][25][26] The microphase separation of BCs is the most suitable approach to obtain selfassembled nanostructures which attract many scientists and scholars due to their potential applications in different fields such as lithography, [27][28][29][30][31][32] drug delivery, [33][34][35][36] membranes, [37][38][39][40] photonics, [41][42][43][44] sensors, [45][46][47][48] biomaterials, [49][50][51][52] surfactants, [53][54][55] thermoplastic elastomers [56][57][58][59][60] as well as energy and data storage. [61][62][63]…”