Journal Article

FZJ-2022-02989

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Aggregation Behavior of Nonsymmetrically End-Capped Thermoresponsive Block Copolymers in Aqueous Solutions: Between Polymer Coils and Micellar States

Prause, A. ; Hechenbichler, M. ; von Lospichl, B. ; Feoktystov, A.FZJ* ; Schweins, R. ; Mahmoudi, N. ; Laschewsky, A. (Corresponding author) ; Gradzielski, M. (Corresponding author)

2022
Soc. Washington, DC

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Please use a persistent id in citations: http://hdl.handle.net/2128/31738  doi:10.1021/acs.macromol.2c00878

Abstract: The thermosensitive aggregation behavior in an aqueous solution of a library of amphiphilic BAB* copolymers is studied, where “A” represents a long permanently hydrophilic poly(N,N-dimethylacrylamide) (pDMAm) block, “B” represents a permanently hydrophobic end with an n-dodecyl chain, and “B*” represents a thermoresponsive (TR) block featuring a lower critical solution temperature (LCST). Four polyacrylamides are employed for B*, namely, poly(N-n-propylacrylamide) (pNPAm), poly(N-isopropylacrylamide) (pNiPAm), poly(N,N-diethylacrylamide) (pDEAm), and poly(N-acryloylpyrrolidine) (pNAP), which differ with respect to the hydrophilicity of their amide side chains and LCST behavior. While blocks A and B were kept constant, the lengths of the TR blocks were varied systematically. These amphiphilic copolymers were studied as a function of concentration and temperature via light and neutron scattering (static light scattering (SLS), dynamic light scattering (DLS), small-angle neutron scattering (SANS)). For sufficiently long pNiPAM and pDEAm blocks (DPn > 40), a pronounced hydrophobic effect at temperatures above the LCST transition results in well-structured, ordered aggregates. Thus, the aggregation can be controlled by the choice and length of the TR block, thereby elucidating a so far hardly explored class of temperature-sensitive polymeric amphiphiles.

Keyword(s): Polymers, Soft Nano Particles and Proteins (1st) ; Chemistry (2nd) ; Soft Condensed Matter (2nd)

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Contributing Institute(s):

1. JCNS-FRM-II (JCNS-FRM-II)
2. Heinz Maier-Leibnitz Zentrum (MLZ)
3. Neutronenstreuung (JCNS-1)
4. JCNS-4 (JCNS-4)

Research Program(s):

1. 6G4 - Jülich Centre for Neutron Research (JCNS) (FZJ) (POF4-6G4) (POF4-6G4)
2. 632 - Materials – Quantum, Complex and Functional Materials (POF4-632) (POF4-632)

Experiment(s):

1. KWS-1: Small angle scattering diffractometer (NL3b)

Appears in the scientific report 2022

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Database coverage:
; ; Chemical Reactions ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF >= 5 ; JCR ; Nationallizenz ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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