Cellulose molecular weights determined by viscometry

Evans, Robert; Wallis, A. F. A.

doi:10.1002/app.1989.070370822

Cited by 141 publications

(83 citation statements)

References 12 publications

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“…Measurements were performed on an automatic viscosimeter RHEOTEK RPV-1 following the norm ISO 5351-1. DPs were evaluated following the equation established by Evans [47].…”

Section: Methodsmentioning

confidence: 99%

Evolution and impact of cellulose architecture during enzymatic hydrolysis by fungal cellulases

Chauve¹,

Barré²,

Tapin-Lingua³

et al. 2013

ABB

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The enzymatic hydrolysis of cellulose is still considered as a main limiting step of the biological production of biofuels from ligno-cellulosic biomass. Glycoside hydrolases from Trichoderma reesei are currently used to produce fermentable glucose units from degradation of cellulose packed in a complex assembly of cellulose microfibrils. The present work describes the structural evolution of two prototypical samples of cellulose (a micro-crystalline cellulose and a bleached sulfite pulp) over 5 length scale orders of magnitude. The results were obtained through wide angle, small angle and ultra-small angles synchrotron X-ray scattering, completed by Small Angle Neutron Scattering and particle size analyzers. These structural evolutions were followed as a function of enzymatic conversion. The results show that whereas there is no change at the nanometer scale, drastic changes occur at micron. The observed decrease of the size of the cellulose particles is accompanied by a smoothing of the crystalline surfaces that can be explained by a two-step mechanism of the enzymatic hydrolysis.

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“…Measurements were performed on an automatic viscosimeter RHEOTEK RPV-1 following the norm ISO 5351-1. DPs were evaluated following the equation established by Evans [47].…”

Section: Methodsmentioning

confidence: 99%

Evolution and impact of cellulose architecture during enzymatic hydrolysis by fungal cellulases

Chauve¹,

Barré²,

Tapin-Lingua³

et al. 2013

ABB

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“…Similarly, ash content could not be determined, however, since none of the papers contained fillers as contemporary Western papers do, this is not considered to be a major source of error. The Mark-Houwink-Sakurada equation was used to calculate DP [24].…”

Section: Degree Of Polymerisationmentioning

confidence: 99%

Characterisation of 19th and 20th century Chinese paper

Brown

Lichtblau²,

Fearn

et al. 2017

Herit Sci

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The chemical and physical properties of 19th and 20th century Chinese papers were investigated using a variety of material characterisation methods. A reference collection of 178 Chinese papers, dating from 1799 to 1990 was used, and properties such as pH, degree of polymerisation (DP), lignin content, and tensile strength (zero-span) were determined. Most of the papers were of approximately neutral pH, had a low lignin content and DP similar to pre-19th century European rag paper. It was found that the high inhomogeneity and the typical paper thinness affected tensile testing and as a result, a modified method for zero-span tensile strength test was developed. Using near infrared spectroscopy (NIR), proof-of-concept partial least squares (PLS) applications were developed for determination of tensile strength, pH, DP and for dating of the samples. For the latter, using post-1900 papers, the error of cross validation was 13 years. The presence of lignin was modelled using linear discriminant analysis (LDA), where the model could distinguish between high and low lignin content with 88% accuracy. Using one or multiple sheets for transmission NIR spectroscopy led to PLS results of similar quality, which was attributed to material inhomogeneity.

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“…3), with a, 0.806 and K', 1.26 mL/g (Evans and Wallis 1989), assuming that the intrinsic viscosity is the same for reacted and native cellulose at the same DP (Mishra et al 2011).…”

Section: Degree Of Polymerizationmentioning

confidence: 99%

Toward Industrially Feasible Methods for Following the Process of Manufacturing Cellulose Nanofibers

Moser¹,

Lindström²,

Henriksson³

2015

BioResources

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a Nanocellulose is a recently developed form of cellulose that has the potential to be used in many different industries, ranging from food to high-performance applications. This material is commercially manufactured through the homogenization of chemical pulps, but the process is energy-consuming and is still an important subject for development. Simple, robust methods are required for the quality control and optimization of industrial nanocellulose production. In this study, a number of different methods, based on different principles of monitoring the manufacture of cellulose nanofibers were evaluated and compared for five different nanocellulose qualities, both for their resolution and robustness/ease. Methods based on microscopy, light scattering, centrifugation, and viscosity were examined and all appeared useful for observing the manufacturing process during its initial stage. However, only methods based on centrifugation, turbidity, and transmittance yielded reliable data for the entire manufacturing process. Of these methods, transmittance measurement may be the best candidate for routine use because the method is simple, rapid, and only requires spectrophotometer equipment.

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Cellulose molecular weights determined by viscometry

Abstract: SynopsisThe equation suggested in the standard method SCAN C15:62 for the estimation of the degree of polymerization (DP) of a cellulose sample from its intrinsic viscosity (

Cited by 141 publications

References 12 publications

Evolution and impact of cellulose architecture during enzymatic hydrolysis by fungal cellulases

Evolution and impact of cellulose architecture during enzymatic hydrolysis by fungal cellulases

Characterisation of 19th and 20th century Chinese paper

Toward Industrially Feasible Methods for Following the Process of Manufacturing Cellulose Nanofibers

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