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Production of porous cellulose aerogel fibers by an extrusion process

Karadagli, Ilknur and Schulz, Björn and Schestakow, Maria and Milow, Barbara and Gries, Thomas and Ratke, Lorenz (2015) Production of porous cellulose aerogel fibers by an extrusion process. The Journal of Supercritical Fluids. Elsevier. DOI: http://dx.doi.org/10.1016/j.supflu.2015.06.011 ISSN 0896-8446

Full text not available from this repository.

Official URL: http://www.sciencedirect.com/science/article/pii/S089684461530036X

Abstract

The preparation, production and properties of light weight, porous cellulose aerogels in the form of thin extruded fibers is compared to monolithic pieces. The cellulose aerogels were synthesized from microcrystalline cellulose in a hydrated calciumthiocyanate salt melt, which upon cooling forms a gel at around 80 °C. Twin screw extrusion experiments were performed systematically yielding thin and wet cellulose filaments. Washing and coagulation of the wet gels in ethanol was followed by supercritical drying with CO2 yielding cellulose aerogel filaments. These were characterized with regard to envelope density, nitrogen adsorption-desorption (BET) analysis, thermal conductivity measurements, tensile and compression tests and scanning electron microscopy (SEM). The microstructure can be described as an open porous network of nano-fibrils with pore sizes ranging from 10 to 100 nm and fibril diameters of around 10 to 25 nm. The densities of supercritically dried (SCD) cellulose aerogels were in the range of 0.009–0.137 g/cm3 and the BET specific surface areas (SSABET) were between 120 and 230 m2/g. The cellulose aerogel possessed thermal conductivities from 0.04 to 0.075 W/m.K and compressive moduli up to 16.2 MPa. The tensile strength of aerogel filaments increases with the increasing cellulose amount in the spin dope. Extruded cellulose aerogel filaments show a dependency of their specific surface area on the extrusion temperature: the higher the spinning temperature the higher the surface area.

Item URL in elib:https://elib.dlr.de/98137/
Document Type:Article
Title:Production of porous cellulose aerogel fibers by an extrusion process
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Karadagli, Ilknur1Institut für WerkstoffforschungUNSPECIFIED
Schulz, BjörnInstitut für Textiltechnik (ITA) RWTH AachenUNSPECIFIED
Schestakow, Maria1Institut für WerkstoffforschungUNSPECIFIED
Milow, BarbaraBarbara.Milow (at) dlr.deUNSPECIFIED
Gries, ThomasITA-RWTH AachenUNSPECIFIED
Ratke, Lorenzlorenz.ratke (at) dlr.deUNSPECIFIED
Date:2015
Journal or Publication Title:The Journal of Supercritical Fluids
Refereed publication:Yes
Open Access:No
Gold Open Access:No
In SCOPUS:Yes
In ISI Web of Science:Yes
DOI :http://dx.doi.org/10.1016/j.supflu.2015.06.011
Publisher:Elsevier
ISSN:0896-8446
Status:Published
Keywords:Twin screw extrusion, Salt hydrate melt, Cellulose aerogel, Aerogel fiber, Supercritical drying
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Transport
HGF - Program Themes:Transport System
DLR - Research area:Transport
DLR - Program:V VS - Verkehrssystem
DLR - Research theme (Project):V - Verkehrsentwicklung und Umwelt II (old)
Location: Köln-Porz
Institutes and Institutions:Institute of Materials Research > Aerogele
Deposited By: Karadagli, Ilknur
Deposited On:28 Sep 2015 08:54
Last Modified:08 Mar 2018 18:37

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