Gelation behavior of cellulose in NaOH/urea aqueous system via cross-linking

Qin, Xingzhen; Lu, Ang; Zhang, Lina

doi:10.1007/s10570-013-9961-z

Cited by 68 publications

(32 citation statements)

References 37 publications

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“…Pure cellulose is also capable of forming gels, however, in order to produce hydrogels it requires the use of special solvents, such as alkali-urea (Cai and Zhang 2006;Qin et al 2013), DMAc-LiAc (Ishii et al 2006) or ionic liquid (Kadokawa et al 2008) systems.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of cellulose derivative based superabsorbent hydrogels by radiation induced crosslinking

et al. 2014

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Hydrogels with high water uptake were prepared by ionizing radiation induced crosslinking in aqueous solutions of four cellulose derivatives (carboxymethylcellulose sodium salt-CMC-Na, methylcellulose-MC, hydroxyethylcellulose-HEC and hydroxypropylcellulose-HPC). The gel fraction increased with absorbed dose, while water uptake decreased. At high polymer concentrations lower gel fractions were found due to the lower polymer chain mobility and inhomogeneity at low water content. The swelling rate gradually slowed down after 4-5 h. CMC and HEC gels reached equilibrium after 24 h, while HPC and MC gels required longer immersion times. Gels showed second-order swelling kinetics in water. The mechanism of the water diffusion proved to be anomalous. In pure water, CMC gels showed the highest, while HPC and MC gels the lowest water uptake. The derivatives had different sensitivities to ionic strength in the swelling solution. The salt type also proved to be a significant factor at uniform ionic strength. Thus different cellulose derivative based gels may be preferred at various applications depending on the environment.

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Section: Introductionmentioning

confidence: 99%

Synthesis of cellulose derivative based superabsorbent hydrogels by radiation induced crosslinking

et al. 2014

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“…A combination of the halide and epoxide functional groups, such as epichlorohydrin, is frequently used in crosslinking for cellulose based hydrogels synthesis . Cellulose hydrogels have been “one‐step” synthesized from cellulose in NaOH/urea aqueous solution using epichlorohydrin as a crosslinker . The gelation was controlled by a synergy of chemical and physical crosslinking processes, namely, the etherification reaction between cellulose and epichlorohydrin, as well as the self‐association and entanglement of cellulose chains via hydrogen bonding reconstruction from cellulose/NaOH/urea aqueous solutions .…”

Section: Chemical Crosslinked Cellulose‐based Gelsmentioning

confidence: 99%

“…Cellulose hydrogels have been “one‐step” synthesized from cellulose in NaOH/urea aqueous solution using epichlorohydrin as a crosslinker . The gelation was controlled by a synergy of chemical and physical crosslinking processes, namely, the etherification reaction between cellulose and epichlorohydrin, as well as the self‐association and entanglement of cellulose chains via hydrogen bonding reconstruction from cellulose/NaOH/urea aqueous solutions . Cellulose/chondroitin sulfate (CS) hydrogels were also prepared with esterification crosslinking and used for drug delivery.…”

Section: Chemical Crosslinked Cellulose‐based Gelsmentioning

confidence: 99%

Cellulose-Based Gels

Kang

Liu

Huang

2016

Macromol. Chem. Phys.

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Cellulose is the most available biomacromolecule in nature with the properties of renewability, biodegradability, biocompatibility, and environmental friendliness. Cellulose and its derivatives are excellent building blocks for fabrication of gels. In this review, the principles for preparing cellulose‐based gels are summarized in detail. Considering the native properties of cellulose and its derivatives, chemical and/or physical crosslinking can be introduced during the preparation of cellulose‐based gels. The chemical and physical crosslinking approaches are classified alongside the introduction of new concepts in polymer science, such as supramolecular interactions. Cellulose graft copolymers are another kind of building block in the fabrication of cellulose‐based gels. The properties of gels can be tailored by the chemical structure of the graft chains. Cellulose‐based gels can be applied in many fields depending on their properties.

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“…However, both, the solution viscosity and the properties of cellulose hydrogels made from this solvent can be adjusted by introducing additional amounts of undissolved cellulose particles as a physical cross-linker [18]. Cellulose solutions based on NaOH and urea also show a unique, irreversible gelation behaviour when heated [19,20]. This behaviour has been explored previously to 3D print non-derivatized cellulose using a focused laser beam to locally heat the cellulose solution beyond its gelation point [21].…”

Section: Introductionmentioning

confidence: 99%

3D Printing of Gelled and Cross-Linked Cellulose Solutions; an Exploration of Printing Parameters and Gel Behaviour

et al. 2020

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In recent years, 3D printing has enabled the fabrication of complex designs, with low-cost customization and an ever-increasing range of materials. Yet, these abilities have also created an enormous challenge in optimizing a large number of process parameters, especially in the 3D printing of swellable, non-toxic, biocompatible and biodegradable materials, so-called bio-ink materials. In this work, a cellulose gel, made out of aqueous solutions of cellulose, sodium hydroxide and urea, was used to demonstrate the formation of a shear thinning bio-ink material necessary for an extrusion-based 3D printing. After analysing the shear thinning behaviour of the cellulose gel by rheometry a Design of Experiments (DoE) was applied to optimize the 3D bioprinter settings for printing the cellulose gel. The optimum print settings were then used to print a human ear shape, without a need for support material. The results clearly indicate that the found settings allow the printing of more complex parts with high-fidelity. This confirms the capability of the applied method to 3D print a newly developed bio-ink material.

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Gelation behavior of cellulose in NaOH/urea aqueous system via cross-linking

Cited by 68 publications

References 37 publications

Synthesis of cellulose derivative based superabsorbent hydrogels by radiation induced crosslinking

Synthesis of cellulose derivative based superabsorbent hydrogels by radiation induced crosslinking

Cellulose-Based Gels

3D Printing of Gelled and Cross-Linked Cellulose Solutions; an Exploration of Printing Parameters and Gel Behaviour

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