Use of Microfibrillated Cellulose/Lignosulfonate Blends as Carbon Precursors: Impact of Hydrogel Rheology on 3D Printing

Abstract

The aim of the present study was to investigate the rheological properties of microfibrillated cellulose/lignosulfonate hydrogels and to use them for the manufacturing of carbon objects by 3D printing and carbonization. To this purpose, both flow mode and thixotropic mode were used to characterize the hydrogel rheological behaviour which was subsequently used to search for formulation/processability correlations during 3D printing of square cuboids. At a concentration of 2%, microfibrillated cellulose (MFC) displayed excellent printability, i.e. a shear thinning behaviour with high yield stress and a viscoelastic response to a step-down shear rate variation. The addition of lignosulfonate (LS) induced a drop in the yield stress and, above a LS mass fraction of 30%, the MFC/LS hydrogel displayed an inelastic thixotropic response with a drop in printability (viz. the printed cuboids underwent a continuous deformation until hydrogel complete spreading). Above 50% of LS, the high viscosity slowed down the flow of MFC/LS hydrogels and printed cuboids had minor deformation. Freeze and air drying of cuboids printed with LS mass fraction lower than 20% and higher than 50%, respectively, allowed keeping the original shape and their carbonization under inert gas led to the production of highly conducting objects. In line with the high density of air dried samples, carbonized samples displayed an irregular structure with pores and crackles generated during drying and carbonization, whereas freeze dried samples had the typical lamellar structure of icetemplated materials.

Impact of rheological properties of mashed potatoes on 3D printing

“…7) also indicates that more solid-like 269 behavior and poor fluidity of 4% PS mixture. The poor extrudability of mixture with 270 high viscosity was not consistent with the results of Shao et al (2015), who reported 271 that when high viscosity of microfibrillated cellulose/hydrogels suspension was used 272 in printing, the square cuboids could be easily printed without compressed 273 deformations. However, their edges showed rounded profiles because that high 274 viscosity of suspending medium led to the difficulty of stopping the flow of the 275 suspension immediately after extrusion.…”

Investigation on lemon juice gel as food material for 3D printing and optimization of printing parameters

“…The properties and composition of materials have been considered to be the most important factors in 3D printing process. These materials should be homogenous and have appropriate flow properties for extrusion as well as can support its structure during and after printing process (Godoi et al, 2016;Shao, Chaussy, Grosseau, & Beneventi, 2015). Zhang et al (2015) used dual-responsive hydrogels to fabricate three-dimensional objects via extrusion from a nozzle in 3D printing.…”

The effect of consistency on the shear rheology of aqueous suspensions of cellulose micro- and nanofibrils: a review

“…The rheological characteristics of various CMNF suspensions has become a widely discussed topic. Although knowledge on rheological behavior is naturally important in the use of CMNFs as a rheology modifier (Dimic-Misic et al 2013;Shao et al 2015;Li et al 2015) and stabilizer (Andresen and Stenius 2007;Winuprasith and Suphantharika 2013), such information is also needed for CMNF production (Delisée et al 2010;Pääkkönen et al 2016;Colson et al 2016) and for other CMNF-related processes (Saarikoski et al 2015;Shao et al 2015;Hoeng et al 2017;Kumar et al 2017). A recent thorough review of the rheology of CMNF suspensions can be found in (Hubbe et al 2017).…”