Composition, particle size, charge and colloidal stability of pH-fractionated humic acids

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26310%2F15%3APU113810" target="_blank" >RIV/00216305:26310/15:PU113810 - isvavai.cz</a>

Výsledek na webu

<a href="http://link.springer.com/article/10.1007/s11368-015-1142-2?wt_mc=email.event.1.SEM.ArticleAuthorAssignedToIssue" target="_blank" >http://link.springer.com/article/10.1007/s11368-015-1142-2?wt_mc=email.event.1.SEM.ArticleAuthorAssignedToIssue</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s11368-015-1142-2" target="_blank" >10.1007/s11368-015-1142-2</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Composition, particle size, charge and colloidal stability of pH-fractionated humic acids

Popis výsledku v původním jazyce

Purpose: The purpose of this study was to divide humic acids into several fractions by means of their dissolving in buffers with different pH values and to characterize obtained humic fractions with respect to their composition, structure, particle size and charge. Relation-ships between determined characteristics of fractionated humic acids and pH values of used buffer solutions and the method of fractionation was investigated. Materials and methods: Humic acids were fractionated by means of two different methods: the subsequent dissolution in buffers adjusted to different pH and the sequential dissolution in buffers with increasing pH values. Composition, structure and properties of the obtained humic fractions were studied using elemental analysis, FT-IR spectroscopy, UV/VIS spectroscopy and light scattering methods. Results and discussion: As expected, fractions obtained by subsequent dissolution were more heterogeneous than those prepared by sequential extraction. Fractions obtained at lower pH values contained higher amounts of aromatic and carboxylic groups, while those extracted at higher pH values were rich in aliphatic and/or peptide groups. Fractions extracted close to neutral pH region had some specific properties. Functional groups dissociated in a range of pH values depending on the chemical structure of the molecules. Weaker carboxylic groups could dissociate in less acidic solutions and more aromatic fractions could be dissolved. Conformational changes and deaggregation process differed with the fractionation procedure and concentration of studied solutions. A bimodal distribution of particle sizes and higher values of polydispersity were obtained for some for less concentrated solutions of humic fractions. Conclusions: Obtained humic fractions behave as anionic heterogeneous ligands with many carboxylic and phenolic groups of different strength, and present polyfunctional and polyelectrostatic effects due to different functional sites and net charge

Název v anglickém jazyce

Composition, particle size, charge and colloidal stability of pH-fractionated humic acids

Popis výsledku anglicky

Purpose: The purpose of this study was to divide humic acids into several fractions by means of their dissolving in buffers with different pH values and to characterize obtained humic fractions with respect to their composition, structure, particle size and charge. Relation-ships between determined characteristics of fractionated humic acids and pH values of used buffer solutions and the method of fractionation was investigated. Materials and methods: Humic acids were fractionated by means of two different methods: the subsequent dissolution in buffers adjusted to different pH and the sequential dissolution in buffers with increasing pH values. Composition, structure and properties of the obtained humic fractions were studied using elemental analysis, FT-IR spectroscopy, UV/VIS spectroscopy and light scattering methods. Results and discussion: As expected, fractions obtained by subsequent dissolution were more heterogeneous than those prepared by sequential extraction. Fractions obtained at lower pH values contained higher amounts of aromatic and carboxylic groups, while those extracted at higher pH values were rich in aliphatic and/or peptide groups. Fractions extracted close to neutral pH region had some specific properties. Functional groups dissociated in a range of pH values depending on the chemical structure of the molecules. Weaker carboxylic groups could dissociate in less acidic solutions and more aromatic fractions could be dissolved. Conformational changes and deaggregation process differed with the fractionation procedure and concentration of studied solutions. A bimodal distribution of particle sizes and higher values of polydispersity were obtained for some for less concentrated solutions of humic fractions. Conclusions: Obtained humic fractions behave as anionic heterogeneous ligands with many carboxylic and phenolic groups of different strength, and present polyfunctional and polyelectrostatic effects due to different functional sites and net charge

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

<a href="/cs/project/LO1211" target="_blank" >LO1211: Centrum materiálového výzkumu na FCH VUT v Brně - udržitelnost a rozvoj</a><br>

Návaznosti

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

Rok uplatnění

2015

Kód důvěrnosti údajů

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

Název periodika

Journal of Soils and Sediments

ISSN

1439-0108

e-ISSN

1614-7480

Svazek periodika

15

Číslo periodika v rámci svazku

9

Stát vydavatele periodika

DE - Spolková republika Německo

Počet stran výsledku

9

Strana od-do

1900-1908

Kód UT WoS článku

000359938600006

EID výsledku v databázi Scopus

2-s2.0-84939472257