Thermodynamics of the multi-stage self-assembly of pH-sensitive gradient copolymers in aqueous solutions

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389013%3A_____%2F16%3A00461607" target="_blank" >RIV/61389013:_____/16:00461607 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1039/C6SM01105E" target="_blank" >http://dx.doi.org/10.1039/C6SM01105E</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/C6SM01105E" target="_blank" >10.1039/C6SM01105E</a>

Result language

angličtina

Original language name

Thermodynamics of the multi-stage self-assembly of pH-sensitive gradient copolymers in aqueous solutions

Original language description

The self-assembly thermodynamics of pH-sensitive di-block and tri-block gradient copolymers of acrylic acid and styrene was studied for the first time using isothermal titration calorimetry (ITC) and dynamic light scattering (DLS) performed at varying pH. We were able to monitor each step of micellization as a function of decreasing pH. The growth of micelles is a multi-stage process that is pH dependent with several exothermic and endothermic components. The first step of protonation of the acrylic acid monomer units was accompanied mainly by conformational changes and the beginning of self-assembly. In the second stage of self-assembly, the micelles become larger and the number of micelles becomes smaller. While solution acidity increases, the isothermal calorimetry data show a broad deep minimum corresponding to an exothermic process attributed to an increase in the size of hydrophobic domains and an increase in the structure's hydrophobicity. The minor change in heat capacity (ΔCp) confirms the structural changes during this exothermic process. The exothermic process terminates deionization of acrylic acid. The pH-dependence of the ζ-potential of the block gradient copolymer micelles exhibits a plateau in the regime corresponding to the pH-controlled variation of the micellar dimensions. The onset of micelle formation and the solubility of the gradient copolymers were found to be dependent on the length of the gradient block.

Czech name

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Czech description

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Type

J_x - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)

CEP classification

CF - Physical chemistry and theoretical chemistry

OECD FORD branch

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Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2016

Confidentiality

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

Name of the periodical

Soft Matter

ISSN

1744-683X

e-ISSN

—

Volume of the periodical

12

Issue of the periodical within the volume

32

Country of publishing house

GB - UNITED KINGDOM

Number of pages

11

Pages from-to

6788-6798

UT code for WoS article

000382112600009

EID of the result in the Scopus database

2-s2.0-84982133338