Cellulosic fiber: mechanical fibrillation-morphology-rheology relationships

Yuan, Tianzhong; Zeng, Jinsong; Wang, Bin; Cheng, Zheng; Chen, Kefu

doi:10.1007/s10570-021-04034-y

Cited by 14 publications

(4 citation statements)

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“…Schenker et al (2018) used viscosity and viscoelastic measurements to qualitatively describe the increase in network strength as the degree of fibrillation (DoF) increased in eucalyptus pulp cellulose nanofibres. Yuan et al (2021) also noted the increase in viscosity flow curves as the DoF increased in CNF samples. They qualitatively linked this to increasing aspect ratios, although their reported fibre aspect ratios were determined by AFM and SEM, not the viscosity profiles.…”

Section: Introductionmentioning

confidence: 78%

Rapid cellulose nanomaterial characterisation by rheology

et al. 2023

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Cellulose nanomaterial (CNM) aspect ratio strongly influences sheet formation and resulting mechanical, optical, and barrier properties. However, there is a lack of fast and reliable methods for CNM aspect ratio determination, limiting the reliable production of nanocellulose at industrial-scale. Current laboratory approaches comprise microscopic (e.g. atomic force microscopy (AFM) and transmission electron microscopy (TEM)), and sedimentation methods, which are time-consuming and limited to specific CNM fibre sizes. Here, we describe a new rheological method to determine the aspect ratios for the whole size range of cellulose fibres using rheology. Cellulose nanocrystals (CNCs), cellulose nanofibres (CNFs), and wood fibres in the form of Bleached Eucalyptus Kraft (BEK) were investigated. The aspect ratios of these three scales of cellulose fibres were determined by measuring the specific viscosity profiles of their suspensions at different concentrations from high to low shear rates (2000–0.001 s−1), and evaluating whether the fibre suspensions exhibited entangled or disentangled behaviour. The rheological results agreed well with those produced by AFM and sedimentation methods. Furthermore, cellulose fibre aspect ratios determined with specific viscosity measurements were generated in 5 hours for each feedstock, while sedimentation and AFM required at least 2 days to produce the same results. Ultimately, we demonstrate that rheology is a rapid and accurate method to determine the aspect ratio for the whole range of cellulose fibre sizes, a critical step towards facilitating their full-scale application.

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Section: Introductionmentioning

confidence: 78%

Rapid cellulose nanomaterial characterisation by rheology

et al. 2023

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“…Generally, MFC suspensions exhibit high viscosities at low shear rates, and a significant shear-thinning behaviour with increasing shear rates, while the viscosity increases, preferably with the fibrils` surface charging rather than with the increasing concentration of MFC (Vesterinen et al 2010;Iotti et al 2011;Karppinen et al 2011;Moberg et al 2017). A transition region (Karppinen et al 2011) and a shear-rate viscosity hysteresis loop effect with a dilatant (non-Newtonian) behaviour at lower shear rates (usually up to 50 s −1 ), has also been reported for most MFC suspensions, already from 1 wt% of solid content (Iotti et al 2011;Yuan et al 2021), thus explaining the shear-induced structural changes of the initial aggregated / flocculated network structure by increasing the shearing. Additional studies (Saarikoski et al 2012;Koponen 2000) also revealed that such a fibrils` flocculation network separates first into chain-like floc formations, and, by further shear rate increase, into individual spherical flocs, the size of which is inversely proportional to the shear rate, and dependent on the geometry gap affecting the measured shear stress.…”

Section: Introductionmentioning

confidence: 63%

Influence of hydroxyethyl and carboxymethyl celluloses on the rheology, water retention and surface tension of water-suspended microfibrillated cellulose

Kokol

2022

Cellulose

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Water-soluble polymers have been shown to improve the flow rigidity and water retention ability of highly-branched (flocculated) and polydisperse water-suspended MFC, thereby also modifying and controlling their rheological behaviour. The addition of hydroxyethyl (HEC) and carboxymethyl (CMC) celluloses of different content (5–10–20 w/w%), molecular weights (MW, 90.000–1.300.000 g/mol) and degrees of substitutions (DS, 0.7–1.2) to 1.5 wt% MFC suspension, have thus been studied by evaluating their microstructure (SEM imaging), strength and rheological properties, i.e. the yield stress and flow under rotational (viscosity vs. shear rate) and oscillatory (viscoelastic) regime, using cone-plate measuring geometry at a rather low truncation gap. The pure MFC suspension showed high-viscosity at lower shear stress and shear-thinning behaviour at higher rates, with two yielding zones, indicating a secondary deflocculation of smaller and more stiffly packed fibril structures and their orientation/aligning in the direction of flow. This behaviour was reduced substantially by the addition of high-MW HEC, or almost eliminated completely by medium-MW CMCs with higher DS, yielding suspensions with higher and stability-prolonged zero-shear viscosity, as well as a more linearly decreased and irreversible viscosity profile after the shear load removal at higher shear stresses. The carboxylic groups at CMC additionally decreased the interactions between the fibrils, and subsequently reduced the fibrils’ flocks, or formed larger aggregates with their integrations, while increasing the MFC suspension gel-strength, improving its flow and viscoelastic behaviour through higher water retention ability and surface tension properties, and also its recovery after deformation.

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“…The study investigates the influences of particle size distribution and interparticle friction coefficient on the solid phase stresses, bulk friction coefficient, and jamming transition, which are investigated. Yuan et al 8 examined the relationship between mechanical fibrillation, morphological properties, and the rheological behavior of cellulosic fibers, considering the winding and interaction of fibers in fiber suspension fluids. Uniform dispersion of fibers in the fracturing fluid enhances the fluid viscosity, which may be called the viscosification of fibers.…”

Section: Introductionmentioning

confidence: 99%

Prediction of Proppant Settling Velocity in Fiber-Containing Fracturing Fluids

Bai,

2023

ACS Omega

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Hydraulic fracturing is the main stimulation method in the development of oil and gas fields. It is helpful to predict the fracture support effect during fracturing by calculating the settling velocity of particles in the fracturing fluid. Experimental research shows that fibers mixed into the fracturing fluid can improve the performance of suspended sand. In this study, fiber was considered a solvent in the fracturing fluid, and the constitutive model of the fiber-containing fracturing fluid was modified according to the fluid rheology. From the analysis of the mechanical behavior in the fibercontaining fluid, the settling velocity of particles slowed down because of some reasons. First, the viscosity of the fiber-containing fracturing fluid increased significantly. The other mechanism is the resistance mechanism of the fiber acting on the particle. The apparent viscosity was fitted based on the rheological model and the measurements. Then, the drag coefficient model of the settling particles was built according to the rheological data of the fibrous fluid. A semi-empirical model was developed to predict the terminal settling velocity through research on dynamics. By characteristic analysis of the results, we found that the fiber on the settling velocity is closely related to the concentration of the base fluid. This prediction model is suitable for the base fluid and fiber-containing fracturing fluid, and the average relative difference between the prediction model and measurements was acceptable.

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Cellulosic fiber: mechanical fibrillation-morphology-rheology relationships

Cited by 14 publications

References 50 publications

Rapid cellulose nanomaterial characterisation by rheology

Rapid cellulose nanomaterial characterisation by rheology

Influence of hydroxyethyl and carboxymethyl celluloses on the rheology, water retention and surface tension of water-suspended microfibrillated cellulose

Prediction of Proppant Settling Velocity in Fiber-Containing Fracturing Fluids

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