Controlling the transparency and rheology of nanocellulose gels with the extent of carboxylation

Mendoza, David Joram; Hossain, Laila; Browne, Christine; Raghuwanshi, Vikram Singh; Simon, George P.; Garnier, Gil

doi:10.1016/j.carbpol.2020.116566

Cited by 47 publications

(35 citation statements)

References 42 publications

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“…In addition, the CNCs from the kapok fibers tended to be more transparent than those from the balsa. The high transparency of the CNCs was affected by the low wavelength CNCs of kapok [ 30 ].…”

Section: Resultsmentioning

confidence: 99%

“…The highest absolute ZP was achieved after 16 h of oxidation (62.27 mV) in the kapok CNCs, indicating an increase in the carboxyl group content after the oxidation process with the APS oxidation method. The primary hydroxyl groups on the cellulose surface were converted to carboxyl groups after the APS oxidation method [ 30 ]. The ZP value after 16 h oxidation time in this study was higher than that previously reported with the APS oxidation method and other methods ( Table 2 ).…”

Section: Resultsmentioning

confidence: 99%

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Effect of Oxidation Time on the Properties of Cellulose Nanocrystals Prepared from Balsa and Kapok Fibers Using Ammonium Persulfate

et al. 2021

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This study aimed to evaluate the effect of ammonium persulfate’s (APS) oxidation time on the characteristics of the cellulose nanocrystals (CNCs) of balsa and kapok fibers after delignification pretreatment with sodium chlorite/acetic acid. This two-step method is important for increasing the zeta potential value and achieving higher thermal stability. The fibers were partially delignified using acidified sodium chlorite for four cycles, followed by APS oxidation at 60 °C for 8, 12, and 16 h. The isolated CNCs with a rod-like structure showed an average diameter in the range of 5.5–12.6 nm and an aspect ratio of 14.7–28.2. Increasing the reaction time resulted in a gradual reduction in the CNC dimensions. The higher surface charge of the balsa and kapok CNCs was observed at a longer oxidation time. The CNCs prepared from kapok had the highest colloid stability after oxidation for 16 h (−62.27 mV). The CNCs with higher crystallinity had longer oxidation times. Thermogravimetric analysis revealed that the CNCs with a higher thermal stability had longer oxidation times. All of the parameters were influenced by the oxidation time. This study indicates that APS oxidation for 8–16 h can produce CNCs from delignified balsa and kapok with satisfactory zeta potential values and thermal stabilities.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Effect of Oxidation Time on the Properties of Cellulose Nanocrystals Prepared from Balsa and Kapok Fibers Using Ammonium Persulfate

et al. 2021

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“…where V 1 and V 2 are the volume of NaOH required to neutralise the carboxylic acid, C is the molarity of sodium hydroxide, ω is the weight of dry CMF, and 111 is the molar mass difference of 2,3,6tricarboxycellulose and anhydroglucose unit (Mendoza et al 2020).…”

Section: Ds = (1)mentioning

confidence: 99%

“…Nanocellulose particles can be produced solely by mechanical forces (Zimmermann et al 2004;Hietala et al 2016;Mendoza et al 2019), but because this is highly energy consuming, some chemical or enzymatic pretreatments have been established, which decrease the energy consumption, as well as the ber damage (Jiang et al 2017;Hu et al 2018). The most common chemical pretreatment is by applying 2,2,6,6-Tetramethylpiperidine-1-oxyl known as TEMPO-mediated oxidation, which produces carboxylated nano ber (CNF) with limited carboxyl charges (0.8-1.7 mmol/g), as only the C6 hydroxyl groups are carboxylated (Mendoza et al 2020;Isogai et al 2020). For the production of carboxylated nanocellulose, the TEMPO method creates thin nano brils with uniform sizes.…”

Section: Introductionmentioning

confidence: 99%

Microspheres and Nanorods Produced in the Dissolution of Mildly Carboxylated Cellulose Fibers in Alkaline Solutions

Moradian

Ven

2021

Preprint

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A mild etherification of spruce kraft pulp was performed to introduce 1.3 and 2.5 mmol/g carboxyl groups on cellulose chains. 1.3 mmol/g carboxymethyl fibers (CMF) were dissolved partially in alkaline water to form balloons and collars on the tracheid and their ultra-structure was investigated. Primary wall, expanded S1, swollen S2, wrinkled S3, spiral bands of S1, parallel microfibrils of S2 and their transverse splitting were observed on swollen fibers. It is indicated that balloons, collars and wrinkled S3 were formed due to different cellulose microfibril features in different layers of tracheid cell wall. Microspheres with a size up to about 0.6 µm were observed by field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). It is shown that they originated from transverse splitting of S2 microfibrils and contain bundles of well-known cellulose nanocrystals (CNC). After homogenization and sonication of an aqueous dispersion of 2.5 mmol/g CMF, electroacoustic spectroscopy showed the presence of nanorods with a size distribution of 18-208 nm. Similar sizes were observed by TEM.

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“…Not only did CNCs act as an effective dispersing medium for DEF, but they also served as excellent nano-reinforcements in PVA films. CNCs (or nanocellulose, in general) are ideal nanomaterials for functionalization owing to their tunable surface chemistry, excellent mechanical properties, unique optical properties, and biodegradability [ [18] , [19] , [20] ].…”

Section: Introductionmentioning

confidence: 99%

Diethyl sinapate-grafted cellulose nanocrystals as nature-inspired UV filters in cosmetic formulations

Mendoza

Maliha

Raghuwanshi

et al. 2021

Materials Today Bio

Self Cite

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Inspired by nature’s photoprotection mechanisms, we report an effective UV-blocking nanomaterial based on diethyl sinapate-grafted cellulose nanocrystals (CNC-DES). The colloidal stability and UV-blocking performance of CNC-DES in aqueous glycerol (a common humectant in petroleum-free cosmetic formulations) and in a commercially available moisturizing cream were studied. Grafting the water-insoluble DES onto CNCs renders it dispersible in these water-based formulations, thanks to the excellent water-dispersibility of CNC nanoparticles. Glycerol dispersions containing 0.1 to 1.5 wt% CNC-DES display very high UV-blocking activity owing to the anti-UV DES moieties anchored onto CNCs. A facial cream blended with 1.5 wt% CNC-DES exhibits an SPF of 5.03, which is higher than a commercially available sunscreen with the same active ingredient concentration (SPF = 3.84). DPPH radical scavenging assay also showed the antioxidant potential of CNC-DES, albeit coinciding with a significant reduction in antioxidant activity after grafting DES onto CNCs. Cytotoxicity measurements revealed the CNC-DES not to cause significant cytotoxicity to murine fibroblast cells after 24 h of exposure. Overall, CNC-DES exhibits strong anti-UV and antioxidant properties and is water-dispersible, biocompatible, non-greasy, and lightweight. This study demonstrates the exceptional potential of DES-grafted CNCs as nature-inspired UV filters in the next generation of cosmetic formulations, including those for sensitive skins.

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Controlling the transparency and rheology of nanocellulose gels with the extent of carboxylation

Cited by 47 publications

References 42 publications

Effect of Oxidation Time on the Properties of Cellulose Nanocrystals Prepared from Balsa and Kapok Fibers Using Ammonium Persulfate

Effect of Oxidation Time on the Properties of Cellulose Nanocrystals Prepared from Balsa and Kapok Fibers Using Ammonium Persulfate

Microspheres and Nanorods Produced in the Dissolution of Mildly Carboxylated Cellulose Fibers in Alkaline Solutions

Diethyl sinapate-grafted cellulose nanocrystals as nature-inspired UV filters in cosmetic formulations

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