Cellulose Aerogel Fibers Tested on a REXUS 18 Rocket – The ACTOR Project

Schulz, Björn; Meinert, Tobias; Bierbüsse, David; Busen, Michel; Körtzinger, Nina; Stankowski, Michael; Seide, Gunnar Henrik

doi:10.1002/cite.201600003

Cited by 8 publications

(4 citation statements)

References 11 publications

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“…Porous cellulose fibers with a diameter about 500 μm and 93-99% porosity were prepared by dissolving cotton linters in Ca(SCN) 2 or ZnCl 2 salt hydrate melt, then homogenized by a twin-screw extruder, and wet-spun into ethanol, finally dried in supercritical CO 2 [10]. The best fibers produced showed better heat resistance than cotton cloth under space flight conditions [11]. Both dissolution and coagulation are, however, chemically intensive, and the processes required to produce salt-free fibers are time-consuming.…”

Section: Introductionmentioning

confidence: 99%

Nanocellulose aerogel-based porous coaxial fibers for thermal insulation

2020

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Strong, continuous, and highly porous coaxial fibers with cellulose nanofibril (CNF) aerogel core and celluloserich sheath were fabricated by wet-spinning hollow fibers and infusing them with aerogel precursor for highperformance thermal insulators. The sheath contained multiscale pores, including microvoids (14.5 μm) and sub-micron pores (133 nm) in bulk, as well as ca. 25-26 nm surface nanopores, to function as a template and protective sheath for the microporous CNF aerogel core. The porous coaxial fibers had many desirable qualities, including low density (0.2 g cm 3), high porosity (85%), high specific tensile strength (23.5 � 2.5 MPa g cm À 3), wide working temperatures (À 20 to 150 � C), continuous and large-scale producibility, as well as biodegradability. The unique combination of multiscale porous sheath and ultra-low density aerogel core synergistically minimizes heat conductivity by all three mechanisms, i.e., restrain air circulation to limit convective heat transfer, while the poor conducting cellulose permitting little conductive heat transfer and the highly crystalline aerogel cellular walls prohibit infrared radiation, effectively suppresses radiative heat transfer under extreme temperatures.

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Section: Introductionmentioning

confidence: 99%

Nanocellulose aerogel-based porous coaxial fibers for thermal insulation

2020

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“…Alongside sCO 2 drying processes, the regeneration solvent is also essential in achieving a low amount of closed pores. Isopropanol was used as the main regeneration and washing solvents since its low surface tension (0.023 N/m) tends to decrease the number of closed pores during supercritical drying; besides, in previous studies, it has been proven the CAs regenerated in iPrOH have higher mechanical properties than other forms of alcohols (e.g., EtOH) [3,30].…”

Section: Discussionmentioning

confidence: 99%

“…Karadagli et al investigated the spinning dope preparation, extrusion, and characteristics of porous cellulose aerogels fibers from a similar solution and regeneration bath using a micro-extruder and sCO 2 drying [29]. CA fibers have been also fabricated from ZnCl 2 salt melt hydrate in similar processing methods in order to investigate their insulation properties in aerospace [30] and automobile applications [31].…”

Section: Introductionmentioning

confidence: 99%

Effect of Cellulose Characteristics on the Properties of the Wet-Spun Aerogel Fibers

et al. 2021

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Cellulose aerogels (CAs) from plant or bacterial-derived cellulose have advantages such as low density, high porosity, and high specific surface area and have been used in various applications including biomedical fields. One limiting factor in developing CAs is their demanding shaping process since it involves several steps of dissolution/dispersion of cellulose, geometry configurations using molds or nozzles, coagulation and washing of the gel body, and drying techniques. CA fibers can be converted into textiles and enhance the design ability, stiffness, and flexibility of the CAs. This study aims to understand the correlations between the initial cellulose characteristics, aerogel’s internal structure, and its prospective biomedical application. Wet-spun CA fibers were obtained by supercritical CO2 drying from low and high molecular weight microcrystalline cellulose in calcium thiocyanate tetrahydrate solution. Fiber spinning, thermal behavior, textural properties, and biological assessments of the CA fibers were inspected. The CA microfibers from high molecular weight cellulose proved to have a higher surface area (~197 m2/g), denser structure, and finer nanofibrils (~2 nm) with better thermal stability in comparison with the fibers produced from low molecular weight cellulose. The fibers were nontoxic, and cell proliferation was observed over time. CA fibers showed promising results to be used for biomedical applications such as tissue engineering and wound care.

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“…On the other hand, traditional freeze-or wet-spinning technologies can be exploited to fabricate aerogel fibres. 165 These methods can usually be used for flexible aerogels only, such as those made with graphene, 112-114 GO, 166 cellulose, [167][168][169][170] and polyimide. 165 Filaments can be fabricated using a 3D extrusion method, which is somewhat similar to the traditional spinning techniques.…”

Section: Benefits Of Printing Compared To Other Aerogel Shaping Methodsmentioning

confidence: 99%