Hard and transparent films formed by nanocellulose-TiO2 nanoparticle hybrids.
The formation of hybrids of nanofibrillated cellulose and titania nanoparticles in aqueous media has been studied. Their transparency and mechanical behavior have been assessed by spectrophotometry and nanoindentation. The results show that limiting the titania nanoparticle concentration below 16 vol% yields homogeneous hybrids with a very high Young's modulus and hardness, of up to 44 GPa and 3.4 GPa, respectively, and an optical transmittance above 80%. Electron microscopy shows that higher nanoparticle contents result in agglomeration and an inhomogeneous hybrid nanostructure with a concomitant reduction of hardness and optical transmittance. Infrared spectroscopy suggests that the nanostructure of the hybrids is controlled by electrostatic adsorption of the titania nanoparticles on the negatively charged nanocellulose surfaces.
Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden.
Christina
C
Schütz
Jordi
J
Sort
Zoltán
Z
Bacsik
Vitaliy
V
Oliynyk
Eva
E
Pellicer
Andreas
A
Fall
Lars
L
Wågberg
Lars
L
Berglund
Lennart
L
Bergström
German
G
Salazar-Alvarez
D002482:Cellulose / Q000737:chemistry*; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D008854:Microscopy, Electron; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D013053:Spectrophotometry; D055672:Static Electricity; D014025:Titanium / Q000737:chemistry*
C009495:titanium dioxide; D002482:Cellulose; D014025:Titanium