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Schenzel, Karla; Fischer, Steffen

doi:10.1023/a:1016616920539

Cited by 181 publications

(89 citation statements)

References 19 publications

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“…The increase at ca. 896 cm -1 has been assigned to bending mode of HCC and HCO localised at the C6 carbon of anhydroglucopyranose units of cellulose (Schenzel and Fischer 2001). On the other hand, the change in the relative band height at ca.…”

Section: Raman Spectroscopymentioning

confidence: 99%

“…Raman spectroscopy has recently gained rather widespread use in studying crystallinity and the effect of mercerization on crystallinity and structure of cellulose Schenzel et al 2005;Kong and Eichhorn 2005;Jähn et al 2002), partly due to relatively fast and simple sample preparation. In mercerization studies of fibres from various sources Raman spectroscopy has been combined with for example X-ray diffraction (Zhu et al 2004;Schenzel and Fischer 2001) and environmental scanning electron microscopy (ESEM) (Jähn et al 2002). ESEM images illustrated morphological changes in fibre bundles due to alkali treatment, but not on a very small scale.…”

Section: Introductionmentioning

confidence: 99%

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Effect of alkaline treatment on cellulose supramolecular structure studied with combined confocal Raman spectroscopy and atomic force microscopy

Eronen¹,

Österberg²,

Jääskeläinen³

2008

Cellulose

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The aim of this work was to investigate the morphological and structural changes associated with mercerization of cellulose fibres with combined confocal Raman and atomic force microscopy (AFM). During mercerization the alkali induces a change in polymorphic lattice from cellulose I to II. This was observed by confocal Raman spectroscopy from cellulose samples treated with 10, 15 and 25% aqueous sodium hydroxide solution. AFM images from the same samples illustrated that microfibrils were swollen and more granular in cellulose II than in cellulose I. Raman spectral images in plane and depth directions showed that the polymorphous cellulose structure was uniform throughout the cell wall, whereas the microfibril orientation varied between fibre cell wall layers. The changes in microfibril orientation on the sample surfaces were confirmed by AFM images measured from the same sample position.

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Section: Raman Spectroscopymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effect of alkaline treatment on cellulose supramolecular structure studied with combined confocal Raman spectroscopy and atomic force microscopy

Eronen¹,

Österberg²,

Jääskeläinen³

2008

Cellulose

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“…For instance, microcrystalline cellulose (2a) has additional Raman bands between 380 and 460 cm −1 which can be assigned to δ(CCC), δ(CO), δ(CCO) binding vibrations and ring deformations. [26] The strong Raman band around 477 cm −1 , which can be assigned to the ν(CC) backbone stretch, [27] is characteristic of substances that contain starches (3a, 3b and 3c). For starch, only the Raman spectrum of wheat starch (3a) is presented since this spectrum is similar to that of pure amylose and different starches (rice, corn and potato).…”

Section: Polysaccharidesmentioning

confidence: 99%

Reference database of Raman spectra of pharmaceutical excipients

Veij

Vandenabeele

Beer

et al. 2008

J Raman Spectroscopy

194

100

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Raman spectroscopy has evolved into an important fast, direct and nondestructive technique in pharmaceutical analysis. Usually, the focus in this field is mainly on the active ingredients and not on the excipients present in the drugs. A collection of Raman spectra of widely used pharmaceutical excipients is presented in this article, which can serve as a reference for the interpretation of Raman spectra during drug analysis (including classical qualitative and quantitative pharmaceutical analysis, counterfeit tracing and process analytical technology (PAT) applications). The 43 analyzed excipients can be classified into seven categories: mono-and disaccharides (dextrose, lactitol, maltitol, lactose and sucrose), polysaccharides (microcrystalline cellulose, methylcellulose (MC), carboxymethylcellulose (CMC), hydroxypropyl cellulose (HPC), hydroxypropyl methylcellulose (HPMC), wheat starch, maltodextrin, primojel, tragacanth and pectin), polyalcohols (propylene glycol, erythritol, xylitol, mannitol and sorbitol), carboxylic acids and salts (alginic acid, glycine, magnesium stearate, sodium acetate and sodium benzoate), esters (arachis oil, lubritab, dibutyl sebacate, triacetin, Eudragit E100 and Eudragit RL100), inorganic compounds (calcium phosphate, talc, anatase and rutile (TiO 2 ), calcium carbonate, magnesium carbonate, sodium bicarbonate and calcium sulfate) and some unclassified products [gelatin, macrogol 4000 (polyethylene glycol (PEG), polyvinyl pyrrolidone and sodium lauryl sulfate].

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“…The polymorphic transformation followed by FT Raman spectroscopy and microspectroscopy was described earlier. [9] As a result of fiber cleaning and refining the uniaxial morphology of the hemp fiber cells became obvious by the ESEM investigations.…”

Section: Resultsmentioning

confidence: 99%

Orientation Dependent FT Raman Microspectroscopy on Hemp Fibers

Kovur

Schenzel

Diepenbrock

2008

Macromolecular Symposia

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Summary: FT Raman microspectroscopy was used for polarization experiments on strained hemp fibre cells. The cellulosic plant fibers were macerated with alkaline and enzymatic solutions. Those cleaned and refined single fiber cells were subjected to micro tensile tests as well as to polarization measurements under the FT Raman microscope. Mechanical parameters of the fiber cells (e.g. E-modulus) were determined and changes in orientation of the -(C-O-C)-structure units of the cellulose were considered with respect to fiber stress and molecular fiber structures. Intensity ratios R 1 and R 2 calculated on the polarized micro FT Raman spectra of the strained fibers describe the order parameter hP 2 i and hP 4 i allowing the quantitative determination of the orientation of the structure units -(C-O-C)-of fiber cellulose with respect to the fiber cell axis.

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Untitled

Cited by 181 publications

References 19 publications

Effect of alkaline treatment on cellulose supramolecular structure studied with combined confocal Raman spectroscopy and atomic force microscopy

Effect of alkaline treatment on cellulose supramolecular structure studied with combined confocal Raman spectroscopy and atomic force microscopy

Reference database of Raman spectra of pharmaceutical excipients

Orientation Dependent FT Raman Microspectroscopy on Hemp Fibers

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