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Aminzadeh, Selda
Publications (5 of 5) Show all publications
Henriksson, G., Berglund, J., Wohlert, J., Lawoko, M., Aminzadeh, S., Lindström, M. & Vilaplana, F. (2018). Non-cellulose wood polysaccharides - a need for a stricter structural and functional classification?. Paper presented at 255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water, MAR 18-22, 2018, New Orleans, LA. Abstract of Papers of the American Chemical Society, 255
Open this publication in new window or tab >>Non-cellulose wood polysaccharides - a need for a stricter structural and functional classification?
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2018 (English)In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-240158 (URN)000435537702766 ()
Conference
255th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nexus of Food, Energy, and Water, MAR 18-22, 2018, New Orleans, LA
Note

QC 20190108

Available from: 2019-01-08 Created: 2019-01-08 Last updated: 2019-01-08Bibliographically approved
Budnyak, T., Aminzadeh, S., Pylypchuk, I., Riazanova, A., Tertykh, V., Lindström, M. & Sevastyanova, O. (2018). Peculiarities of synthesis and properties of lignin-silica nanocomposites prepared by sol-gel method. Nanomaterials, 8(11), 1-18, Article ID 950.
Open this publication in new window or tab >>Peculiarities of synthesis and properties of lignin-silica nanocomposites prepared by sol-gel method
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2018 (English)In: Nanomaterials, ISSN 2079-4991, Vol. 8, no 11, p. 1-18, article id 950Article in journal (Refereed) Published
Abstract [en]

The development of advanced hybrid materials based on polymers from biorenewable sources and mineral nanoparticles is currently of high importance. In this paper, we applied softwood kraft lignins for the synthesis of lignin/SiO2 nanostructured composites. We described the peculiarities of composites formation in the sol-gel process through the incorporation of the lignin into a silica network during the hydrolysis of tetraethoxysilane (TEOS). The initial activation of lignins was achieved by means of a Mannich reaction with 3-aminopropyltriethoxysilane (APTES). In the study, we present a detailed investigation of the physicochemical characteristics of initial kraft lignins and modified lignins on each step of the synthesis. Thus, 2D-NMR, P-31-NMR, size-exclusion chromatography (SEC) and dynamic light scattering (DLS) were applied to analyze the characteristics of pristine lignins and lignins in dioxan:water solutions. X-Ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) were used to confirm the formation of the lignin-silica network and characterize the surface and bulk structures of the obtained hybrids. Termogravimetric analysis (TGA) in nitrogen and air atmosphere were applied to a detailed investigation of the thermal properties of pristine lignins and lignins on each step of modification. SEM confirmed the nanostructure of the obtained composites. As was demonstrated, the activation of lignin is crucial for the sol-gel formation of a silica network in order to create novel hybrid materials from lignins and alkoxysilanes (e.g., TEOS). It was concluded that the structure of the lignin had an impact on its reactivity during the activation reaction, and consequently affected the properties of the final hybrid materials.

Place, publisher, year, edition, pages
MDPI, 2018
Keywords
lignin, silica, sol-gel process, hybrid composites, thermal analysis
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:kth:diva-239348 (URN)10.3390/nano8110950 (DOI)000451316100085 ()30453688 (PubMedID)2-s2.0-85050597754 (Scopus ID)
Note

QC 20181122

Available from: 2018-11-21 Created: 2018-11-21 Last updated: 2019-09-18Bibliographically approved
Aminzadeh, S. (2018). Valorization of Kraft Lignin by Fractionation and Chemical Modifications for Different Applications. (Doctoral dissertation). Stockholm, Sweden: KTH Royal Institute of Technology
Open this publication in new window or tab >>Valorization of Kraft Lignin by Fractionation and Chemical Modifications for Different Applications
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Abstract

Lignin is one of the most abundant biopolymers. Approximately 70 million tons of technical lignin is generated annually, but only little is used for products other than energy. The complexity of lignin hinders full utilization in high-value products and materials. In spite of the large recent progress of knowledge of lignin structure and biosynthesis, much is still not fully understood, including structural inhomogeneity. We made synthetic lignin at different pH’s and obtained structural differences that might explain the structural inhomogeneity of lignin.

Technical lignins from the chemical pulping are available in large scale, but the processes result in alterations, such as oxidation and condensation. Therefore, to utilize technical lignin, modifications, such as fractionation and/or chemical modifications are necessary. Fractionation with ceramic membranes is one way to lower the polydispersity of lignin. The main advantage is their tolerance towards high temperature and harsh conditions. We demonstrated that low Mw lignin was extracted from industrially produced LignoBoost lignin aiming: i) to investigate the performance of the membrane over time; ii) to analyze the antioxidant properties of the low Mw lignin.

Chemical modification can also improve the properties of lignin. By adding moieties, different properties can be obtained. Amination and methacrylation of kraft lignin were performed, as well as lignin-silica hybrid materials with potential for the adsorption were produced and investigated.

Non-modified and methacrylated lignin were used to synthesize lignin-St-DVB porous microspheres to be utilized as a sorbent for organic pollutants. The possibility to substitute styrene with methacrylated lignin was evaluated, demonstrating that interaction between lignin and DVB, and porosity increased.

Lignin has certain antibacterial properties. Un-modified and modified (aminated) lignin samples and sphere nanoparticles of lignin were tested for their effect against gram-positive and gram-negative bacteria’s and an injectable hydrogel was developed with encapsulated lignin for being used as an injectable gel for the open wounds. Results demonstrated promising antibacterial efficiency of lignins against gram-positive, more especially better inhibition with aminated lignins against gram-positive and negative bacterium.

 

 

Abstract [sv]

SAMMANFATTNING

Lignin är en av de mest förkommande biopolymererna och ca 70 miljoner ton av tekniskt lignin produceras årligen, men endast en mindre del används till andra applikationer än energiproduktion. Ett hinder för användning av lignin i mer komplexa produkter och material är dess komplexa struktur. Trotts senare års stora framsteg när det gäller kunskap om ligninets struktur, är mycket alltjämt dåligt förstått, exempelvis angående den strukturella inhomogeniteten hos lignin. Vi har studerat detta genom att göra syntetiskt lignin vid olika pH, och erhöll strukturella skillnader som kan vara en förklaring till den strukturella inhomogeniteten.

Tekniska ligniner från kemisk massatillverkning är tillgängliga i stor skala, men processerna resulterar i strukturella modifieringar hos ligninet, såsom oxidationer och kondensationer. Därför är fraktionering och modifiering av tekniskt lignin lämpligt. Fraktionering med hjälp av keramiska membran är ett sätt att minska polydisperiteten hos lignin. Den största fördelen är membranens stora tolerans mot höga temperatur och aggressiva kemikalier. Vi använde filtrering på keramiska membran för att framställa lågmolekylärt lignin från den industriella kvaliteten LignoBoost, för att utvärdera membranens prestanda över tid, och analysera antioxidantegenskaperna hos det lågmolekylära ligninet.

Kemisk modifiering kan också användas för att förbättra egenskaperna hos lignin. Genom att koppla på grupper, kan egenskaperna ändras. Amidering och metakrylering av sulfatlignin utfördes liksom tillverkning av lignin-silikon-hybridmaterial, med potential för adsorption, och materialen undersöktes.

Omodifierat och metakrylerat lignin användes tillsammans med styren för att syntetisera porösa mikrosfärer som testades som absorbent för organiska föroreningar. Utvärdering visade att metakrylering ökade interaktionen mellan lignin och polystyren och ökade porositeten.

Lignin har viss antimikrobiell aktivitet. Omodifierade och amiderade ligninprover och sfäriska nanopartiklar av lignin testades för sin verkan mot gram-positiva och gram-negativa bakterier. Resultaten visade lovande resultat för antimikrobiell aktivitet, och särskilt för amiderade ligniner när det gäller grampositiva bakterier. En injicerbar hydrogel med inkapslat lignin utvecklades också för behandling av öppna sår.

 

 

Place, publisher, year, edition, pages
Stockholm, Sweden: KTH Royal Institute of Technology, 2018. p. 92
Series
TRITA-CBH-FOU ; 2018-61
Keywords
Lignin Valorization- LignoBoost Lignin-Clean Flow Black Lignin- Characterization-Chemical modifications-Fractionation-applications
National Category
Paper, Pulp and Fiber Technology
Research subject
Chemical Engineering
Identifiers
urn:nbn:se:kth:diva-239356 (URN)978-91-7873-046-9 (ISBN)
Public defence
2018-12-14, F3, Lindstedtsvägen 26, Stockholm, 14:00 (English)
Opponent
Supervisors
Note

QC 20181122

Available from: 2018-11-22 Created: 2018-11-21 Last updated: 2018-11-26Bibliographically approved
Aminzadeh, S., Mattsson, T., Henriksson, G. & Lindström, M. (2016). On the crossflow membrane fractionation of lignoboost kraft lignin: Characterization of low molecular weight fractions. Abstracts of Papers of the American Chemical Society, 251
Open this publication in new window or tab >>On the crossflow membrane fractionation of lignoboost kraft lignin: Characterization of low molecular weight fractions
2016 (English)In: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 251Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2016
National Category
Organic Chemistry
Identifiers
urn:nbn:se:kth:diva-242665 (URN)000431903802242 ()
Note

QC 20190225

Available from: 2019-02-25 Created: 2019-02-25 Last updated: 2019-08-21Bibliographically approved
Aminzadeh, S., Haghniaz, R., Ottenhall, A., Sevastyanova, O., Lindström, E. & Khademhosseini, A.Lignin based hydrogel for the antibacterial application.
Open this publication in new window or tab >>Lignin based hydrogel for the antibacterial application
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(English)Manuscript (preprint) (Other academic)
National Category
Other Chemistry Topics
Identifiers
urn:nbn:se:kth:diva-239424 (URN)
Note

QC 20181122

Available from: 2018-11-22 Created: 2018-11-22 Last updated: 2018-11-22Bibliographically approved
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