TEMPO-CNF suspensions in the viscoelastic regime: capturing the effect of morphology and surface charge with a rheological parameter

Liao, Jianshan; Pham, Kevin; Breedveld, Victor

doi:10.1007/s10570-020-03572-1

Cited by 19 publications

(19 citation statements)

References 48 publications

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“…The slow viscosity decrease in our studies associated with microstructural rearrangements is also observed when commercially available TEMPO-CNF slurry products are diluted. 9,20 Reverse Dialysis to Dewater CNC, ChNF, and Composite Gels. In addition to TEMPO-CNF, suspensions of CNC and ChNF can be prepared at high concentrations reverse dialysis.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…All TEMPO-CNF used in this study was pressure homogenized (25 000 psi, seven passes) using procedures described in detail in a previous publication. 20 Two TEMPO-CNF batches were prepared around the maximum operating concentration of 0.5 wt % of the homogenizer: 0.48 wt % (for rotary evaporation experiments) and 0.54 wt % (for reverse dialysis); homogenization makes it hard to control the concentration exactly. Scanning electron microscopy (SEM) images of CNC and TEMPO-CNF before and after homogenization are shown in Figure S1.…”

Section: ■ Materials and Methodsmentioning

confidence: 99%

“…Rheological measurements were performed following the procedures described in detail in our previous paper on characterization of CNM, using a rotational rheometer (MCR 302, Anton-Paar) with a cone-plate geometry, Peltier temperature control (25 °C), and an evaporation blocker. 20,22 Figure 1. Schematic of the reverse dialysis setup in this study; the sample to be dewatered is inside the dialysis bag immersed in the PEG solution; water is transported across the dialysis membrane due to osmotic pressure differences.…”

Section: ■ Materials and Methodsmentioning

confidence: 99%

“…Poly(vinyl alcohol) (PVA) of molecular weight 89 000–98 000 (>99% hydrolyzed) and poly(ethylene glycol) (PEG) of molecular weight 35 000 were obtained from Sigma-Aldrich (St. Louis, MO). All TEMPO-CNF used in this study was pressure homogenized (25 000 psi, seven passes) using procedures described in detail in a previous publication . Two TEMPO-CNF batches were prepared around the maximum operating concentration of 0.5 wt % of the homogenizer: 0.48 wt % (for rotary evaporation experiments) and 0.54 wt % (for reverse dialysis); homogenization makes it hard to control the concentration exactly.…”

Section: Methodsmentioning

confidence: 99%

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Dewatering Cellulose Nanomaterial Suspensions and Preparing Concentrated Polymer Composite Gels via Reverse Dialysis

Liao

Pham

Breedveld

2021

ACS Sustainable Chem. Eng.

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Cellulose nanomaterials (CNMs) are typically produced in aqueous suspensions at low concentrations, which require subsequent dewatering to reduce transportation cost or as a preprocessing step for applications that require higher CNM loadings such as rheological modifiers and composites. Reverse dialysis is an effective method that avoids common dewatering issues like irreversible aggregation and sample heterogeneity. In this study, samples for dewatering were placed inside a dialysis bag and immersed in poly(ethylene glycol) (PEG) solution. The water removal process is driven by the osmotic pressure difference. Dewatered TEMPO-cellulose nanofibril (TEMPO-CNF) was redispersible after allowing for time to rehydrate; the original viscosity was recovered after a dewatering-redilution cycle. The generalizability of reverse dialysis was demonstrated by also dewatering suspensions of cellulose nanocrystal and chitin nanofiber. Furthermore, concentrated and well-dispersed poly(vinyl alcohol) (PVA)/TEMPO-CNF composite gels were obtained via reverse dialysis at loadings that were difficult to achieve by other methods. Reverse dialysis thus increases the processing range for these sustainable nanomaterials while preserving their beneficial morphological properties. Reverse dialysis can be added to manufacturing processes; recycling of the PEG solutions via ultrafiltration can be used to create an energy-efficient, sustainable, closed-loop dewatering process for cellulose nanomaterials that are hard to redisperse.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Section: ■ Materials and Methodsmentioning

confidence: 99%

Section: ■ Materials and Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Dewatering Cellulose Nanomaterial Suspensions and Preparing Concentrated Polymer Composite Gels via Reverse Dialysis

Liao

Pham

Breedveld

2021

ACS Sustainable Chem. Eng.

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“…For the TEMPO-CNF/PVA suspensions, when PVA is in the semidilute and entangled regime, the values of G" exceeds G′ (tan δ > 1) over the entire investigated frequency range. It means that these suspensions are predominantly viscous uids, which is related to the exible PVA polymer chains and weak interaction between TEMPO-CNF brils (Zhou et al 2016, Liao et al 2021). The possible dispersion of TEMPO-CNFs and PVA in the suspension is shown in Scheme 1.…”

Section: Rheology Of Tempo-cnf/pva Suspensionsmentioning

confidence: 99%

Effect of poly(vinyl alcohol) (PVA) concentration on rheological behaviors of TEMPO-mediated oxidized cellulose nanofiber/PVA suspensions

Zhou¹,

Yao

Zhang³

et al. 2022

Preprint

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2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidized cellulose nanofiber (TEMPO-CNF)/poly (vinyl alcohol) (PVA) suspension can be used to prepare composite. Therefore, understanding the viscoelastic property of TEMPO-CNF/PVA suspension is necessary. The analysis of the rheological dates from steady and dynamic rheology indicates that the suspension is pseudoplastic fluid with thixotropic behavior. When the concentration of PVA is in the dilute regime, the gel like behavior of the suspensions turns to liquid like state with the increasing frequency. Such behaviors are related to the entangled network among cellulose fibrils and the hydrogen bond interaction between TEMPO-CNFs and PVA. When the concentration of PVA is in semidilute and entangled regime, the suspensions show liquid character, because the viscosity of the suspensions are mainly determined by the entanglement of PVA molecules in homogeneous state. Furthermore, the TEMPO-CNF/PVA membranes were prepared by solution casting method. The Fourier transform infrared spectroscopy and atomic force microscope data proved the interaction between TEMPO-CNFs and PVA. This research reveals the importance of PVA concentration on the fluid characters of TEMPO-CNF/PVA suspensions, providing the approach to adjust the viscosity of TEMPO-CNF suspensions.

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Equilibrium Moisture Mediated Esterification Reaction to Achieve Over 100% Lignocellulosic Nanofibrils Yield

Zheng,

Zhu,

Sun

et al. 2024

Small

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Lignocellulosic nanofibrils (LCNFs) isolation is recognized as an efficient strategy for maximizing biomass utilization. Nevertheless, achieving a 100% yield presents a formidable challenge. Here, an esterification strategy mediated by the equilibrium moisture in biomass is proposed for LCNFs preparation without the use of catalysts, resulting in a yield exceeding 100%. Different from anhydrous chemical thermomechanical pulp (CTMP0%), the presence of moisture (moisture content of 7 wt%, denoted as CTMP7%) introduces a notably distinct process for the pretreatment of CTMP, comprising the initial disintegration and the post‐esterification steps. The maleic acid, generated through maleic anhydride (MA) hydrolysis, degrades the recalcitrant lignin‐carbohydrate complex (LCC) structures, resulting in esterified CTMP7% (E‐CTMP7%). The highly grafted esters compensate for the mass loss resulting from the partial removal of hydrolyzed lignin and hemicellulose, ensuring a high yield. Following microfluidization, favorable LCNF7% with a high yield (114.4 ± 3.0%) and a high charge content (1.74 ± 0.09 mmol g−1) can be easily produced, surpassing most previous records for LCNFs. Additionally, LCNF7% presented highly processability for filaments, films, and 3D honeycomb structures preparation. These findings provide valuable insights and guidance for achieving a high yield in the isolation of LCNFs from biomass through the mediation of equilibrium moisture.

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TEMPO-CNF suspensions in the viscoelastic regime: capturing the effect of morphology and surface charge with a rheological parameter

Cited by 19 publications

References 48 publications

Dewatering Cellulose Nanomaterial Suspensions and Preparing Concentrated Polymer Composite Gels via Reverse Dialysis

Dewatering Cellulose Nanomaterial Suspensions and Preparing Concentrated Polymer Composite Gels via Reverse Dialysis

Effect of poly(vinyl alcohol) (PVA) concentration on rheological behaviors of TEMPO-mediated oxidized cellulose nanofiber/PVA suspensions

Equilibrium Moisture Mediated Esterification Reaction to Achieve Over 100% Lignocellulosic Nanofibrils Yield

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