Preparation and hydration characteristics of carbodiimide crosslinked lignite humic acids

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26620%2F16%3APU118647" target="_blank" >RIV/00216305:26620/16:PU118647 - isvavai.cz</a>

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S0016706116301197" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0016706116301197</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.geoderma.2016.03.009" target="_blank" >10.1016/j.geoderma.2016.03.009</a>

Result language

angličtina

Original language name

Preparation and hydration characteristics of carbodiimide crosslinked lignite humic acids

Original language description

Polar and apolar moieties of humic acids are spatially separated forming domains of different polarity. In this work, we tested the procedures to crosslink functional groups in polar domains of humic acids by using carbodiimide coupling and analyzed to which extent influenced the modification their hydration properties and stability. For this reason, we prepared eight derivatives of lignite humic acids using either water-soluble N-Ethyl-N'-(3-dimethylaminopropyl)carbodiimide (EDC) or water-insoluble N,N'-dicyclohexylcarbodiimide (DCC) under various conditions. Characterization of prepared derivatives showed that both methods lead to formation of crosslinked humic structures. Using of EDC resulted in lower degree of crosslinking, but better hydration properties. Higher moisture uptake and water holding capacity were observed in humic acids, which were pre-wetted prior to crosslinking for at least 24 h. Although the EDC derivatives of humic acids contained only between 60 and 85% of original free carboxylic groups, they showed similar moisture uptake as parental humic acids by equilibration at relative humidities of both 94% and 76%. Under water-saturated conditions, the EDC derivatives showed faster swelling kinetics and reached almost the same water holding capacity as the original sample after 18 days. However, both the EDC and DCC derivatives began to degrade already after 39 days during swelling tests, which subsequently decreased their hydration. The results suggested that water holding capacity, swelling kinetics and moisture uptake of humic acids were not influenced significantly by the amount of polar groups, but also by their spatial arrangement and distribution. (C) 2016 Elsevier B.V. All rights reserved.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

40104 - Soil science

Project

<a href="/en/project/LQ1601" target="_blank" >LQ1601: CEITEC 2020</a><br>

Continuities

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

Publication year

2016

Confidentiality

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

Name of the periodical

GEODERMA

ISSN

0016-7061

e-ISSN

1872-6259

Volume of the periodical

neuveden

Issue of the periodical within the volume

274

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

8

Pages from-to

10-17

UT code for WoS article

000376543600002

EID of the result in the Scopus database

2-s2.0-84962676801