Characterization of cellulose and cellulose derivatives in solution by high resolution 13C-NMR spectroscopy

Nehls, Irene; Wagenknecht, W.; Philipp, B.; Stscherbina, D.

doi:10.1016/0079-6700(94)90037-x

Cited by 127 publications

(54 citation statements)

References 122 publications

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“…As revealed by means of 13 C NMR spectroscopy the dissolution occurs without a derivatization of the polymer. That means the system TBAF/DMSO is a so-called nonderivatizing cellulose solvent according to the classification of cellulose solvents proposed by Philipp et al 7) In a typical 13 C NMR spectrum, except peaks of the butylammonium moieties (57.7, 22.9, 18.8, and 13.2 ppm) the 6 signals of the unmodified anhydroglucose unit (AGU) appear very well resolved (Fig. 1).…”

Section: Resultsmentioning

confidence: 95%

Effective preparation of cellulose derivatives in a new simple cellulose solvent

Heinze¹,

Dicke

Koschella

et al. 2000

Macromol. Chem. Phys.

260

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Section: Resultsmentioning

confidence: 95%

Effective preparation of cellulose derivatives in a new simple cellulose solvent

Heinze¹,

Dicke

Koschella

et al. 2000

Macromol. Chem. Phys.

260

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“…A small peak could be detected at ı 60, albeit with significantly reduced intensity, indicating conversion of primary methylene carbon to carbonyl carbon which was further confirmed by a new peak near ı 175. Solution 13 C NMR of dissolved cellulose has shown the same chemical shifts, but much broader peaks (Elkafrawy, 1982;Moulthrop et al, 2005;Nehls et al, 1994). Solid-state 13 C NMR of TEMPO oxidized nanocellulose also exhibited a carbonyl peak at ı 174.8 but much broader peaks for all other carbons (Fujisawa, Okita, Saito, Togawa, & Isogai, 2011;Mao, Ma, Law, Daneault, & Brouillette, 2010;Montanari, Rountani, Heux, & Vignon, 2005;Shibata & Isogai, 2003).…”

Section: Nmr Characterization Of Nanocellulosementioning

confidence: 89%

“…The projection of 13 C spectrum correlated with the proton nuclei was shown on the vertical axis and the projection of 1 H spectrum correlated with the carbon nuclei was shown on the horizontal axis. The well resolved 13 C NMR spectrum of cellulose had shown the most deshielded anomeric carbon at ı 102.00, followed by a less deshielded carbon C4 at ı 79.00-80.00 and the most shielded methylene carbon C6 at ı 60.00, with other C2, C3, and C5 signals at around ı 74.00 (Bain, Eaton, Hux, & Tong, 1980;Elkafrawy, 1982;Nehls, Wagenknecht, Philipp, & Stscherbina, 1994). The H1 at ı 4.45 was coupled with anomeric C1 at ı 102.1.…”

Section: Nmr Characterization Of Nanocellulosementioning

confidence: 99%

1D and 2D NMR of nanocellulose in aqueous colloidal suspensions

Jiang

Dallas

Ahn

et al. 2014

Carbohydrate Polymers

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a b s t r a c tThis is the first report on surface structural elucidation of individual nanocellulose as colloidal suspensions by 1D 1 H, 2D heteronuclear single quantum coherence (HSQC) as well as 13 C nuclear magnetic resonance (NMR).1 H NMR of rice straw CNCs (4.7 nm thick, 143 nm long, 0.04 sulfate per AG or 19.0% surface hydroxyl to sulfate conversion) resembled that of homogeneous cellulose solution. Conventional 2D HSQC NMR of CNC, CNF 1.5 (2-14 nm thick, several micrometers long, 0.10 COOH per AG) and CNF10 (2.0 nm thick, up to 1 m long, 0.28 COOH per AG) gave H1:H2 ratios of 1.08:1, 0.97:1 and 0.94:1, respectively, all close to the theoretical 1:1 value for cellulose. The H1:H6 ratios determined from 2D HSQC NMR for CNCs, CNF1.5 and CNF10 were 1:1.47, 1:0.88 and 1:0.14, respectively, and corresponded to 26%, 56% and 93% C6 primary hydroxyl conversion to sulfate and carboxyl groups, consistent with, but more sensitive than those by conductometric titration and X-ray diffraction. Both 1 H and 2D HSQC NMR data confirm that solution-state NMR detects nanocellulose surface carbons and protons primarily, validating this technique for direct surface characterization of nanocellulose in aqueous colloidal suspensions, presenting a sensitive and meaningful NMR tool for direct characterizing individual nanocellulose surfaces in never-dried state.

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“…A região de 87 a 93 ppm corresponde a fase cristalina da estrutura da celulose. 39,40 Gráfico 8. Espectro de RMN de 13 C da nanocelulose isolada do bagaço de laranja industrial…”

Section: Fermentação Com Levedurasunclassified

Orange Biomass By-products

Tasić

2017

Rev. Virtual Quim.

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Abstract:Brazil is the major orange producer in the world that per year counts on about ten million tons of underutilized waste (orange biomass). This biomass has a great potential for ethanol production through the hydrolysis of its high amount of polysaccharides with low cost enzyme cocktails. For this purpose, an enzymatic cocktail of cellulases (FPU 8 mL from Xanthomonas axonopodis pv. citri bacteria was used for the hydrolysis of orange bagasse, thus being able to substitute the use of commercial enzymes, which involve a high cost in an industrial scale. The second phase of the proposed bioprocess for second-generation ethanol from orange biomass is called fermentation with co-cultures, and it ensured the conversion of almost 100 % of the sugars. Hesperidin and nanocellulose were also obtained from bagasse. The hesperidin (1.2 % yield) was obtained in two steps, by liquid-solid extraction and purification, while nanocellulose (1.4 % yield) was obtained through a procedure of extraction, bleaching and nanonization.

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Characterization of cellulose and cellulose derivatives in solution by high resolution 13C-NMR spectroscopy

Cited by 127 publications

References 122 publications

Effective preparation of cellulose derivatives in a new simple cellulose solvent

Effective preparation of cellulose derivatives in a new simple cellulose solvent

1D and 2D NMR of nanocellulose in aqueous colloidal suspensions

Orange Biomass By-products

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