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Publikācija: Lignin Separated from the Hydrolyzate of the Hydrothermal Treatment of Birch Wood and Its Surface Properties

Publication Type Scientific article indexed in SCOPUS or WOS database
Funding for basic activity Unknown
Defending: ,
Publication language English (en)
Title in original language Lignin Separated from the Hydrolyzate of the Hydrothermal Treatment of Birch Wood and Its Surface Properties
Field of research 1. Natural sciences
Sub-field of research 1.4 Chemical sciences
Authors Galija Shulga
Sanita Vītoliņa
Vadims Šakels
Lubova Belkova
Georgeta Cazacu
Cornelia Vasile
Loredana Elena Nita
Keywords Alkali lignin; Globular structure; Hydrolyzate; Nanoparticles; Oil-in-water emulsion; Polyelectrolyte effect; Stabilization; Surface tension; Wood hydrothermal treatment
Abstract The chemical composition, structural features and surface active properties of alkali lignin, separated from the hydrolyzate of the birch wood sawdust treatment in a moderately alkaline water solution at a temperature below 100 °C, were studied. The separated lignin was rich in p-oxyphenylpropane fragments and carbonyl groups, but contained a relatively low amount of aliphatic hydroxyl and methoxyl groups. The carboxyl groups were weaker than those in kraft lignins. The lignin aqueous solutions were structured, containing both nano- and micro-sized colloidal particles. The pronounced amphiphilic character of the lignin molecules governed their low critical micelle concentration (CMC) values and enhanced the surface activity at the water-air and liquid-liquid interfaces. When decreasing the pH and increasing ionic strength, the surface activity of lignin at the air-water interface grew, while that at the oil-water interface dropped. Scanning electron microscopy (SEM) images revealed that the microstructure of the lignin surface consisted of globules, forming extended clusters of the "grape- bunches" type.
Reference Shulga, G., Vītoliņa, S., Šakels, V., Belkova, L., Cazacu, G., Vasile, C., Nita, L. Lignin Separated from the Hydrolyzate of the Hydrothermal Treatment of Birch Wood and Its Surface Properties. Cellulose Chemistry and Technology, 2012, 46, pp.307-318. ISSN 0576-9787.
Additional information Citation count:
  • Scopus  0
ID 24139