Facile cellulose nanofibrils amidation using a ‘one-pot’ approach

Gomez, Francisco; Combariza, Marianny Y.; Blanco‐Tirado, Cristian

doi:10.1007/s10570-016-1174-9

Cited by 28 publications

(22 citation statements)

References 52 publications

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“…Encouraged by this result, we continued our experiment to further confirm the interaction of carboxyl groups for the CTE phenomenon. In this experiment, we used ethylenediamine to react with carboxyl groups on C-CNC in water with different reaction time (Gómez et al, 2017). The prepared C-CNC/EDA was monitored by 1 H NMR.…”

Section: Resultsmentioning

confidence: 99%

Clustering-Triggered Emission of Carboxymethylated Nanocellulose

et al. 2019

Front. Chem.

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Non-conjugated polymers with luminescence emission property have recently drawn great attention due to their promising applications in different areas. Most traditional organic synthetic non-conjugated polymers required complicated synthesis. Herein, we report a non-conjugated biomass material, carboxymethylated nanocellulose (C-CNC), which is found to be practically non-luminescent in dilute solutions, while being highly emissive when aggregated as nanosuspensions. We propose that the luminescence of C-CNC originates from the through-space conjugation of oxygen atoms and carboxyl groups of C-CNC. Thus, a clearer mechanism of clusteroluminescence was provided with the subsequent experiments. The effects of concentration of C-CNC, solvent, temperature and pH have also been investigated. In addition, ethylenediamine (EDA) has been employed to “lock” C-CNC material via the bonding of amide groups with carboxylic groups. As prepared C-CNC/EDA confirmed that the clusteroluminescence was attributed to the amide moieties and through-space conjugation between oxygen and carbonyl moieties. Density functional theory (DFT) calculations have also been employed to confirm the luminescence mechanism. It is believed that such clustering-triggered emission mechanism is instructive for further development of unconventional luminogens.

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Section: Resultsmentioning

confidence: 99%

Clustering-Triggered Emission of Carboxymethylated Nanocellulose

et al. 2019

Front. Chem.

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“…Carboxylic moieties in TOCNs can become reactive points to modulate the hydrophilicity/hydrophobicity of the cellulose surface through chemical modification. Surface −COOH groups can react with amines to form amides using several synthetic approaches. ,,, We have recently reported a “one-pot” cellulose amidation approach using TBTU as a coupling agent and primary alkyl amines (C 12 and C 18 ) . In this synthetic route, initial deprotonation of surface carboxylic acid units in TOCNs occurs under basic conditions (Et 3 N).…”

Section: Resultsmentioning

confidence: 99%

“…The surface hydrophobization reaction used involves the coupling of an activated carboxylic group with primary alkyl amines and has been previously reported by our group . Initially, the TBTU (molar ratio 2:1 TBTU/TOCNs) was dissolved in DMF and added to the TOCN suspension (1 wt %) for “conditioning” under constant stirring for 0.5 h at room temperature.…”

Section: Experimental and Methodsmentioning

confidence: 99%

“…For CA experiments, 200 μL of TOCN (1% w in water), TOCN-AMDC 12 , and TOCN-AMDC 18 (1% w in toluene) suspensions were placed onto dry microscopy glass slides previously treated with a 3:1 sulfuric acid/hydrogen peroxide mixture. The coated glasses were left to dry at room temperature for 24 h, according to a previous report . After solvent evaporation, the contact angle and drop shape analyses were performed by applying a deionized water drop directly on top of the coated glass, using a OCA 15EC (Data Physics, Filderstadt, Germany) measuring device equipped with a dosing syringe, a 6× zoom lens, and a high-resolution video system with an accuracy of 0–180 ± 0.1° for angle measurement.…”

Section: Experimental and Methodsmentioning

confidence: 99%

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Amidated Cellulose Nanofibrils as Demulsifying Agents for a Natural Water-in-Heavy-Crude-Oil Emulsion

Gómez-Jaimes

Blanco‐Tirado

2020

Energy Fuels

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The presence of emulsified water in heavy crude oils invariably causes processing problems and financial costs associated with an increased energy input required to handle highly viscous fluids. Thus, physical or chemical separation methods are usually applied to dehydrate crude oils before processing. Dehydration chemicals or demulsifiers are among the most widely used chemical strategies to rid heavy crude oil from water. In this work, we explore the use of amidated cellulose nanofibrils as dehydrating agents for a water-in-heavy-crude-oil emulsion. Using microcrystalline cellulose (MCC) as raw material, we extracted oxidized cellulose nanofibrils (1.25 mmol COOH/g cellulose) via ultrasound-assisted TEMPO oxidation. TEMPO-oxidized cellulose nanofibrils (TOCNs) were rendered hydrophobic through the coupling with dodecyl-and octadecylamine through one-pot amidation reactions. The introduction of C 12 and C 18 alkyl moieties on the cellulose surface was enough to promote the dispersion of the materials in toluene and increase the water contact angle (CA) from 17°for TOCN to 61°and 67°for TOCN-AMDC 12 and TOCN-AMDC 18 , respectively. HLB values of 9.6 and 9.2 for TOCN-AMDC 12 and TOCN-AMDC 18 are characteristic of dehydrating agents for w/o emulsions. Thus, the materials were tested as demulsifying agents for the disruption of a natural water-inheavy-crude-oil emulsion with a water content of 55%. Conventional tests (BSW, bottle test) showed the ability of TOCN-AMDC 12 and TOCN-AMDC 18 to effectively dehydrate the emulsions, with a water recovery up to 74%, when used at 1500 ppm in toluene as the carrier fluid. Optical microscopy and rheological analysis were performed before and after the nanofluids' application to determine the viscosity profile of the emulsion and to observe the types and sizes of water droplets in the oil phase after dehydration.

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“…Figure 5 depicts the profile of weight loss ( Figure 5a) and derivative weight loss (Figure 5b) of amidated CNF. Thermal degradation of cellulose involves a groups of endothermic reactions that can occur in the form of dehydration, hydrolysis, oxidation, decarboxylation especially for oxidated cellulose and transglycosylation process [19].…”

Section: Atr-ftir Analysismentioning

confidence: 99%

Surface Modification of Tempo-Mediated Cellulose Nanofibril With Octadecylamine

Masruchin

Nuryawan

Kusumaningrum

et al. 2019

jsmi

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SURFACE MODIFICATION OF TEMPO-MEDIATED CELLULOSE NANOFIBRIL WITH OCTADECYLAMINE. In this study, surface modification of 2,2,6,6-tetramethylpiperidine-1-oxyl radical TEMPO-cellulose nanofibrils (TCNF) was obtained by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS)-mediated system. The carboxylate groups on TCNF surface was replaced by conjugation of octadecylamine (ODA). The conversion of the carboxylate groups on CNF into amide I and II groups was confirmed by attenuated transform reflectance-infrared (ATR-FTIR) and elemental analysis study. Further, decarboxylation of TCNF at higher temperature was hindered by the presence of amide groups resulted in the higher thermal stability of TCNF as observed by thermogravimetry analysis (TGA). These results suggested the possibility of modifying surface negatively charged of TCNF with conjugated amine groups into thermally stable nanocellulose.

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Facile cellulose nanofibrils amidation using a ‘one-pot’ approach

Cited by 28 publications

References 52 publications

Clustering-Triggered Emission of Carboxymethylated Nanocellulose

Clustering-Triggered Emission of Carboxymethylated Nanocellulose

Amidated Cellulose Nanofibrils as Demulsifying Agents for a Natural Water-in-Heavy-Crude-Oil Emulsion

Surface Modification of Tempo-Mediated Cellulose Nanofibril With Octadecylamine

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