Cellulose nanofibril core-shell silica coatings and their conversion into thermally stable nanotube aerogels

QC 20150817
A facile water-based one-pot reaction protocol for obtaining 20 nm thick uniform silica coatings on cellulose nanofibrils (CNFs) is herein presented for the first time. The fully covering silica shells result in the thermal stability of the CNFs improved by ca. 70 degrees C and 50 degrees C under nitrogen and oxygen atmospheres, respectively. Heating of the core-shell hybrid fibres to 400 degrees C results in complete degradation/removal of the CNF cores, and demonstrates an inexpensive route to large-scale preparation of silica nanotubes with the CNFs used as templates. The key to a uniform condensation of silica (from tetraethyl orthosilicate) to cellulose is a reaction medium that permits in situ nucleation and growth of the silica phase on the fibrils, while simultaneously matching the quantity of the condensed silica with the specific surface area of the CNFs. Most coatings were applied to bundles of 2-3 associated CNFs, which could be discerned from their negative imprint that remained inside the silica nanotubes. Finally, it is demonstrated that the coated nanofibrils can be freeze-dried into highly porous silica/cellulose aerogels with a density of 0.005 g cm(-3) and how these hybrid aerogels preserve their shape when extensively exposed to 400 degrees C in air (>6 h). The resulting material is the first reported silica nanotube aerogel obtained by using cellulose nanofibrils as templates.

Wu, QiongKTH,Fiber- och polymerteknologi(Swepub:kth)u1he360c (författare)
Andersson, Richard L.KTH,Fiber- och polymerteknologi(Swepub:kth)u1ksh6cc (författare)
Hedenqvist, Mikael S.KTH,Fiber- och polymerteknologi(Swepub:kth)u10rkaxe (författare)
Farris, Stefano (författare)
Olsson, Richard T.KTH,Fiber- och polymerteknologi,Wallenberg Wood Science Center(Swepub:kth)u1ob386f (författare)
KTHFiber- och polymerteknologi (creator_code:org_t)

Ingår i:Journal of Materials Chemistry A: Royal Society of Chemistry3:30, s. 15745-157542050-74882050-7496

Av författaren/redakt...: Liu, Dongming; Wu, Qiong; Andersson, Richa ...; Hedenqvist, Mika ...; Farris, Stefano; Olsson, Richard ...

Om ämnet

TEKNIK OCH TEKNOLOGIER: TEKNIK OCH TEKNO ...; och Maskinteknik; och Energiteknik

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.