Insight into the Structure of a Comb Copolymer-Surfactant Coacervate from Dynamic Measurements by DOSY NMR and Neutron Spin Echo Spectroscopy

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F22%3A10449867" target="_blank" >RIV/00216208:11310/22:10449867 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=OPMDczz8aM" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=OPMDczz8aM</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.macromol.2c00523" target="_blank" >10.1021/acs.macromol.2c00523</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Insight into the Structure of a Comb Copolymer-Surfactant Coacervate from Dynamic Measurements by DOSY NMR and Neutron Spin Echo Spectroscopy

Popis výsledku v původním jazyce

ABSTRACT: Structure and dynamics of an anionic comb polyelectrolyte poly[methacrylic acid-stat-poly(ethylene glycol) methyl ether methacrylate] (PMAA-PEGMA) and a cationic surfactant N-dodecylpyridinium chloride (DPCl) in coacervate emulsion formed by electrostatic complexation of PMAA-PEGMA and DPCl were followed by a combination of diffusion-ordered and nuclear Overhauser effect NMR spectroscopies (DOSY and NOESY NMR), small-angle neutron scattering (SANS), and neutron spin echo (NSE) spectroscopy. The measurements were conducted for various charge ratios Z of the number of DPCl positive charges to the number of PMAA-PEGMA negative charges. NMR spectra showed splitting of signals caused by partitioning of both PMAA-PEGMA and DPCl between the bulk aqueous phase and coacervate particles formed at Z &gt; 0.7, with much slower diffusion of both the polymer and surfactant in the coacervate phase. SANS measurements revealed the formation of two types of DPCl micellar structures in the system: (i) Small elongated micellar aggregates forming the PE-S complex with PMAA-PEGMA chains. These structures exhibited fast diffusion and weak NOESY contacts of DPCl heads with PEGMA side chains. (ii) Large aggregates of densely packed micelles forming the PE-S complex with PMAA-PEGMA chains. These structures exhibited slow diffusion and strong NOESY contacts of DPCl heads with PEGMA side chains. The difference in dynamics between the two types of DPCl aggregates was confirmed by NSE, showing that apparent diffusion coefficients, D-app(q), in the high q region, 1.1-2.0 nm(-1), dominated by scattering from densely packed DPCl micelles were much lower (hydrodynamic radius, R(H) &gt; 10(2) nm) than those in the low q region, 0.2-1.1 nm(-1), dominated by scattering from small elongated aggregates of DPCl micelles (R(H) of ca. 4 nm). NSE measurements thus confirmed that densely packed DPCl micelles were present in large aggregates, while the scattering contribution in 0.2-1.1 nm(-1) originated from small elongated micellar aggregates in the bulk solution.

Název v anglickém jazyce

Insight into the Structure of a Comb Copolymer-Surfactant Coacervate from Dynamic Measurements by DOSY NMR and Neutron Spin Echo Spectroscopy

Popis výsledku anglicky

ABSTRACT: Structure and dynamics of an anionic comb polyelectrolyte poly[methacrylic acid-stat-poly(ethylene glycol) methyl ether methacrylate] (PMAA-PEGMA) and a cationic surfactant N-dodecylpyridinium chloride (DPCl) in coacervate emulsion formed by electrostatic complexation of PMAA-PEGMA and DPCl were followed by a combination of diffusion-ordered and nuclear Overhauser effect NMR spectroscopies (DOSY and NOESY NMR), small-angle neutron scattering (SANS), and neutron spin echo (NSE) spectroscopy. The measurements were conducted for various charge ratios Z of the number of DPCl positive charges to the number of PMAA-PEGMA negative charges. NMR spectra showed splitting of signals caused by partitioning of both PMAA-PEGMA and DPCl between the bulk aqueous phase and coacervate particles formed at Z &gt; 0.7, with much slower diffusion of both the polymer and surfactant in the coacervate phase. SANS measurements revealed the formation of two types of DPCl micellar structures in the system: (i) Small elongated micellar aggregates forming the PE-S complex with PMAA-PEGMA chains. These structures exhibited fast diffusion and weak NOESY contacts of DPCl heads with PEGMA side chains. (ii) Large aggregates of densely packed micelles forming the PE-S complex with PMAA-PEGMA chains. These structures exhibited slow diffusion and strong NOESY contacts of DPCl heads with PEGMA side chains. The difference in dynamics between the two types of DPCl aggregates was confirmed by NSE, showing that apparent diffusion coefficients, D-app(q), in the high q region, 1.1-2.0 nm(-1), dominated by scattering from densely packed DPCl micelles were much lower (hydrodynamic radius, R(H) &gt; 10(2) nm) than those in the low q region, 0.2-1.1 nm(-1), dominated by scattering from small elongated aggregates of DPCl micelles (R(H) of ca. 4 nm). NSE measurements thus confirmed that densely packed DPCl micelles were present in large aggregates, while the scattering contribution in 0.2-1.1 nm(-1) originated from small elongated micellar aggregates in the bulk solution.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10404 - Polymer science

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2022

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Macromolecules

ISSN

0024-9297

e-ISSN

1520-5835

Svazek periodika

55

Číslo periodika v rámci svazku

14

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

9

Strana od-do

6191-6199

Kód UT WoS článku

000824293400001

EID výsledku v databázi Scopus

2-s2.0-85134810381