Rheological and electron microscopic characterization of aqueous carboxymethyl cellulose gels Part I: Rheological aging of aqueous gels of carboxymethyl cellulose in the free acid form (HCMC)

Hakert, H.; Eckert, Th.; Müller, Tobias

doi:10.1007/bf01410579

Cited by 7 publications

(2 citation statements)

References 5 publications

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“…The acid form of CMC (HCMC) was produced according to the method detailed by Dieckman et al 33 using a strongly acidic ionexchange resin; though the procedure we followed was more akin to that done by Hakert et al 34 This was done as opposed to the use of HCl, as this apparently affects the aging of the HCMC gel. Sodium CMC was dissolved in distilled water up to the maximum solubility as mentioned by the manufacturer (20 mg mL −1 ).…”

Section: Preparation Of Acid Form Of Cmcmentioning

confidence: 99%

Synthesis and characterization of polysaccharide hydrogel based on hydrophobic interactions

Fredrick

Podder

Viswanathan

et al. 2019

J of Applied Polymer Sci

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Hydrogels based on hydrophobic, or micellar interactions, are physically crosslinked hydrogels which are an attempt to overcome the poor mechanical properties of traditional, chemically crosslinked gels, such as low shear strength. We have prepared a polysaccharide‐based hydrogel with physical crosslinks via hydrophobic interactions. In this work, we have synthesized hydrogel by grafting a hydrophobic moiety dioctylamine onto hydrophilic precursor carboxymethyl cellulose (CMC) through an amide bond formation, where ~33% of the carboxyl group in CMC was reacted with dioctylamine. The thermosensitive hydrogel can arrest 100 mL of deionized water per gram of gelator within few seconds. It showed the moderate rheological property. The hydrogel is nontoxic and does not show any adverse to human hemoglobin. It is a CMC based a unique gelator with high biocompatibility represent to be useful materials for biomedical application. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47665.

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Section: Preparation Of Acid Form Of Cmcmentioning

confidence: 99%

Synthesis and characterization of polysaccharide hydrogel based on hydrophobic interactions

Fredrick

Podder

Viswanathan

et al. 2019

J of Applied Polymer Sci

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“…The sodium salt of carboxymethylcellulose (NaCMC) is a water-soluble derivative of cellulose, the most abundant polymer on earth, which is broadly used for industrial applications, such as food, pharmaceuticals, paints, etc., and serves as a thickener and water retention agent when dispersed in a solvent. − The properties of NaCMC can be tuned via the degree of substitution (DS), which corresponds to the average number of carboxymethyl groups per repeating glucose unit and varies between 0 and 3. Highly substituted polymers, i.e., for DS ≳ 1, are hydrophilic and disperse easily in water, yielding rheological features typical of polyelectrolyte solutions. − In contrast, weakly substituted polymers, i.e., for DS ≲ 0.9, contain hydrophobic regions, which favor interchain aggregation and the formation of so-called “fringed micelles” in aqueous solution, yielding thixotropic and even gel-like properties at high enough concentrations. − In practice, the gelation of NaCMC solution can be induced by lowering the pH, which decreases the charge density along the CMC chain and promotes the formation of multichain aggregates . At a low enough pH, NaCMC solutions thus behave as soft solids that experience a solid-to-liquid transition at large deformations. , While much is known about the flow properties of highly substituted NaCMC aqueous solutions, the acid-induced gelation of less substituted CMC solutions and the resulting gel properties remain poorly understood in terms of mechanical and structural properties.…”

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confidence: 99%

Acid-Induced Gelation of Carboxymethylcellulose Solutions

Legrand,

Baeza,

Peyla

et al. 2024

ACS Macro Lett.

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The present work offers a comprehensive description of the acid-induced gelation of carboxymethylcellulose (CMC), a water-soluble derivative of cellulose broadly used in numerous applications ranging from food packaging to biomedical engineering. Linear viscoelastic properties measured at various pH and CMC contents allow us to build a sol−gel phase diagram and show that CMC gels exhibit broad power-law viscoelastic spectra that can be rescaled onto a master curve following a time− composition superposition principle. These results demonstrate the microstructural self-similarity of CMC gels and inspire a mean-field model based on hydrophobic interchain association that accounts for the sol−gel boundary over the entire range of CMC content under study. Neutron scattering experiments further confirm this picture and suggest that CMC gels comprise a fibrous network cross-linked by aggregates. Finally, low-field NMR measurements offer an original signature of acid-induced gelation from a solvent perspective. Altogether, these results open avenues for the precise manipulation and control of CMC-based hydrogels.

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Non‐Invasive In Situ Dynamic Monitoring of Elastic Properties of Composite Battery Electrodes by EQCM‐D

et al. 2015

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Reversible Li-ion intercalation into composite Liion battery (LIB) electrodes is often accompanied by significant dimensional electrode changes (deformation) resulting in significant deterioration of the cycling performance.V iscoelastic properties of polymeric binders affected by intercalation-induced deformation of composite LIB electrodes have never been probed in situ on operating electrochemical cells. Here,w ei ntroduce an ewly developed noninvasive method, namely electrochemical quartz-crystal microbalance with dissipation monitoring (EQCM-D), for in situ monitoring of elastic properties of polymeric binders during charging of LIB electrodes.A ss uch,w ef ind EQCM-D as au niquely suitable tool to trackthe binders structural rigidity/softness in composite Li insertion electrodes in real-time by the characteristic increase/decrease of the dissipation factor during the chargingdischarging process.T he binders partially swollen in aprotic solutions demonstrate intermediate viscoelastic charge-ratedependent behavior,r evealing rigid/soft behavior at high/low charging rates,r espectively.T he method can be adjusted for continuous monitoring of elastic properties of the polymeric binders over the entire LIB electrodes cycling life.Lithium-ion batteries (LIB) offer av ery broad spectrum of applications,from portable devices to larger scale all-electric vehicles. [1] Forl arge-scale applications,p orous composite LIBs electrodes are usually used, containing at least three components:e lectrode particles (e.g.,L iFePO 4 ), ab inder (commonly,p olyvinylidene fluoride,P VdF,a nd sodium carboxymethylcellulose,NaCMC), [2] and conductive additives such as carbon black, graphene,o rc arbon nanotubes.T he processes of ions extraction/insertion occurring in LIBs electrodes during their charge/discharge result in periodic potential-dependent changes of the electrodes volume (i.e., their deformation), bringing about av ariety of undesirable mechanical effects,s uch as high-enough stresses,f atigue, fracture,a nd delamination from current collector. [3] Current techniques for in situ monitoring of electrodes strains include atomic force microscopy (AFM) [4] and electrochemical dilatometry. [5] Ac ommon drawback of these techniques is that they do not provide direct information on the potentialinduced changes of the electrode porosity,w hich is an important factor of stress relaxation in LIB electrodes.It has been recently shown that electrochemical quartzcrystal microbalance (EQCM) has at remendous benefit of direct in situ gravimetric probing of ionic fluxes into composite nanoporous carbon electrodes during charging and discharging. [6] Later we have developed as elf-consistent in situ methodology for tracking dimensional changes of this electrode based on EQCM with dissipation monitoring (EQCM-D) and we demonstrated this methods potential for two systems:L iFePO 4 olivine as at ypical composite intercalation-type LIB cathodes material [7] and Ti 3 C 2 M x MXene as acomposite material with properties intermediate between b...

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Rheological and electron microscopic characterization of aqueous carboxymethyl cellulose gels Part I: Rheological aging of aqueous gels of carboxymethyl cellulose in the free acid form (HCMC)

Cited by 7 publications

References 5 publications

Synthesis and characterization of polysaccharide hydrogel based on hydrophobic interactions

Synthesis and characterization of polysaccharide hydrogel based on hydrophobic interactions

Acid-Induced Gelation of Carboxymethylcellulose Solutions

Non‐Invasive In Situ Dynamic Monitoring of Elastic Properties of Composite Battery Electrodes by EQCM‐D

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