Order‐disorder transitions in self‐assembled polymers: A positron annihilation study

Abstract

We report here the first results of order‐disorder transition (ODT) in a self‐assembled comb‐like polymer‐amphiphile supramolecular system as identified from the change in positron lifetime parameters. We have used poly(4‐vinyl pyridine) hydrogen bonded with 3‐pentadecyl phenol, which upon heating showed a stepwise reduction in o ‐Ps intensity at the ODT from lamellar self‐assembled state to the disordered state. The ODT temperature was confirmed by differential scanning calorimetry and small angle X‐ray scattering. The free volume “holes” in this polymer‐amphiphile system are proposed to be near the chain ends of the polymer backbones. We suggest that positron lifetime spectroscopy can serve as a technique to identify ODTs in self‐assembled lamellar structured supramolecular systems. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Disorder-to-Order Transition of Triblock Comb Copolymer Am+1(BC)m

“…14 Even some new techniques are developed to probe the disorder to order transition, such as positron annihilation lifetime spectroscopy. 15 We have already studied the morphology of comb copolymer A m+1 (BC) m in our previous work. 16 In that work, we found the disordered phase exists at the corner of the phase diagram besides the ordered morphologies.…”

“…Moreover, there are many studies related to disorder to order transition (DOT) of block copolymers, such as alkyne/azide click chemistry induced DOT of diblock copolymer . Even some new techniques are developed to probe the disorder to order transition, such as positron annihilation lifetime spectroscopy …”

Frustrated crystallisation and hierarchical self-assembly behaviour of comb-like polymers

“…5). [52][53][54][55][56][57][58][59][60] They also prepared polymeric supramolecular comb-coil diblock co-polymers, comprised of a PS coil-like block and a supramolecular comb-like block based on P4VP, where the pyridines are either directly hydrogen bonded with PDP, i.e., PS-block-P4VP(PDP) 1.0 , or first protonated with methanesulfonic acid (MSA) and then hydrogen bonded to PDP, i.e., PS-block-P4VP(MSA) 1.0 (PDP) 1.0 . 58,61 Their works demonstrated that the comb-like copolymer structures, using physical non-covalent interactions, opens possibilities to prepare tailored microstructures based on the expertise obtained in block copolymers and colloidal systems.…”