ISSN 1070-4272, Russian Journal of Applied Chemistry, 2008, Vol. 81, No. 7, pp. 1171!1174. + Pleiades Publishing, Ltd., 2008.
Original Russian Text + I.Yu. Vashurina, A.S. Pogorelova, Yu.A. Kalinnikov, 2008, published in Zhurnal Prikladnoi Khimii, 2008, Vol. 81, No. 7,
OF SYSTEMS AND PROCESSES
Peat Humates as Alternative to Synthetic Dispersants
in Leuco Acid Process of Fabric Dyeing with Vat Dyes
I. Yu. Vashurina, A. S. Pogorelova, and Yu. A. Kalinnikov
Ivanovo State University of Chemical Technology, Ivanovo, Russia
Institute of Solution Chemistry, Ivanovo, Russia
Received December 25, 2006
Abstract-The effect of humates isolated from peat on the state in solution of the leuco acid of Vat Brilliant
Green C dye was examined spectrophotometrically and compared with the effect of dispersants traditionally
used in textile-chemical processes: disodium methylenebis(naphthalenesulfonate) and triethanolamine.
Peat humates (PHs) are the salt form of humus
acids, specific polymeric organic compounds syn-
thesized in the nature from plant residues under the
action of soil microorganisms and abiotic factors of
the medium. Humus acids are irregular copolymers
of polyhydroxycarboxylic acids, containing also
diverse other fragments (both aliphatic and aromat-
ic) and functional groups (carboxy, hydroxy, phen-
olic, quinone, keto, hydroxymethyl, amino, imino,
etc.) [1, 2]. Therefore, PHs participate in ionic and
donor!acceptor interactions, hydrogen bonding, and
formation of complexes with metals and adducts
with various classes of organic compounds [2!5].
For living bodies, peat humates are nontoxic and
nonteratogenic. They exhibit high physiological
activity, primarily as strong adaptogens .
Peat humates are used in plant and animal breed-
ing [7, 8], in medicine [9!11], in technologies of
soil remediation and wastewater treatment [6, 12,
13], in mining , in building , and in other
branches of economy.
The environmental safety of PHs makes them
very attractive for applications to any fields of
human activity, especially if they can replace less
environmentally friendly synthetic chemicals. The
processes for recovery of humates from peat are
safe and waste-free.
This work continues our studies aimed to sub-
stantiate the feasibility of using PHs in textile finish-
ing processes. Previous studies revealed the capabil-
ity of humates to modify structurally and chemically
starch sizing gels , to catalyze the reduction of
vat dyes in the course of fabric printing [17, 18], and
to improve the parameters of fabric dyeing with vat
dyes (intensity and uniformity of dyeing), especially
in the leuco acid process .
In accordance with this process, a vat dye in the
ionic form, reduced in an alkaline solution, is con-
verted to a nondissociated leuco acid by weak acidi-
fication. The leuco form of the dye forms an unsta-
ble colloidal solution whose stability is provided by
adding special compounds, dispersants. Interaction
of the dye with the dispersant determines not only
the stability of the colloidal solution, but also the
course of sorption of the dye with a fiber and of the
subsequent diffusion in the fiber.
The dispersants traditionally used in dyeing of
fabrics with the leuco acid of a vat dye are disodium
methylenebis(naphthalenesulfonate) (NF, DNF) and
In this study we compared the effects of DNF,
TEA, and PHs on the state in aqueous solution of
the leuco acid of Vat Brilliant Green C dye (VBGC)
with the aim to substantiate the dispersing effect of
PHs exerted on nonionic forms of vat dyes.
Colloidal solutions of VBGC leuco acid were pre-
pared by mixing two components: alkaline solution
of sodium salt of leuco compound of the vat dye and
aqueous solution of acetic acid  into which the
required amount of a dispersant (DNF, TEA, PHs)
was additionally introduced. The pH of the colloidal
solutions prepared was 6.0.