Tuning the collapse transition of weakly charged polymers by ion-specific screening and adsorption

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22340%2F18%3A43916810" target="_blank" >RIV/60461373:22340/18:43916810 - isvavai.cz</a>

Výsledek na webu

<a href="https://pubs.rsc.org/en/content/articlelanding/2018/sm/c8sm01646a#!divAbstract" target="_blank" >https://pubs.rsc.org/en/content/articlelanding/2018/sm/c8sm01646a#!divAbstract</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/c8sm01646a" target="_blank" >10.1039/c8sm01646a</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Tuning the collapse transition of weakly charged polymers by ion-specific screening and adsorption

Popis výsledku v původním jazyce

The experimentally observed swelling and collapse response of weakly charged polymers to the addition of specific salts displays quite convoluted behavior that is not easy to categorize. Here we use a minimalistic implicit-solvent/explicit-salt simulation model with a focus on ion-specific interactions between ions and a single weakly charged polyelectrolyte to qualitatively explain the observed effects. In particular, we demonstrate ion-specific screening and bridging effects cause collapse at low salt concentrations whereas the same strong ion-specific direct interactions drive re-entrant swelling at high concentrations. Consistently with experiments, a distinct salt concentration at which the salting-out power of anions inverts from the reverse to direct Hofmeister series is observed. At this so called isospheric point, the ion-specific effects vanish. Furthermore, with additional simplifying assumptions, an ion-specific mean-field model is developed for the collapse transition which quantitatively agrees with the simulations. Our work demonstrates the sensitivity of the structural behavior of charged polymers to the addition of specific salt beyond simple screening and shall be useful for further guidance of experiments.

Název v anglickém jazyce

Tuning the collapse transition of weakly charged polymers by ion-specific screening and adsorption

Popis výsledku anglicky

The experimentally observed swelling and collapse response of weakly charged polymers to the addition of specific salts displays quite convoluted behavior that is not easy to categorize. Here we use a minimalistic implicit-solvent/explicit-salt simulation model with a focus on ion-specific interactions between ions and a single weakly charged polyelectrolyte to qualitatively explain the observed effects. In particular, we demonstrate ion-specific screening and bridging effects cause collapse at low salt concentrations whereas the same strong ion-specific direct interactions drive re-entrant swelling at high concentrations. Consistently with experiments, a distinct salt concentration at which the salting-out power of anions inverts from the reverse to direct Hofmeister series is observed. At this so called isospheric point, the ion-specific effects vanish. Furthermore, with additional simplifying assumptions, an ion-specific mean-field model is developed for the collapse transition which quantitatively agrees with the simulations. Our work demonstrates the sensitivity of the structural behavior of charged polymers to the addition of specific salt beyond simple screening and shall be useful for further guidance of experiments.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

<a href="/cs/project/GJ16-24321Y" target="_blank" >GJ16-24321Y: Mikroskopický vhled do termodynamiky kolapsu u polymerů citlivých na teplo</a><br>

Návaznosti

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

Rok uplatnění

2018

Kód důvěrnosti údajů

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

Název periodika

SOFT MATTER

ISSN

1744-683X

e-ISSN

—

Svazek periodika

14

Číslo periodika v rámci svazku

47

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

12

Strana od-do

9631-9642

Kód UT WoS článku

000452321400009

EID výsledku v databázi Scopus

2-s2.0-85058182401