On the external morphology of native cellulose microfibrils

The cell walls of members of the Vaucheriaceae and Saprolegniaceae have been examined by X-ray analysis and electron microscopy, and their composition determined by hydrolysis and paper partition chromatography of the hydrolysates. Both differences and similarities between the members of these two species examined are found to supplement the comparative morphological and physiological information at present available. Saprolegnia , Achlya , Brevilegnia and Dictyuchus among the Saprolegniaceae possess hot-water soluble polysaccharides containing glucose residues only. This polysaccharide is not crystallographically identical with the polysaccharide found in Vaucheria sessilis with a similar solubility. The members of the Saprolegniaceae contain large amounts of alkali-soluble polysaccharides in contrast with the negligible amount found in V. sessilis . These polysaccharides are only weakly crystalline, but the indications are that the same polysaccharides may occur throughout the Saprolegniaceae. The alkali-insoluble wall material of Vaucheria species consists of highly crystalline native cellulose with large, apparently randomly arranged, microfibrils. The hydrolysate of this material contains ribose, xylose and arabinose in addition to glucose, presumably representing strongly bound pentosans. Native cellulose also occurs in the Saprolegniaceae but only in small proportion. The bulk of the alkali-insoluble fraction in the walls of these fungi appears amorphous in the electron microscope and is only weakly crystalline. It consists of one or m ore substances containing glucose, mannose, ribose and possibly other sugars together with traces of glucosamine. These substances presumably cover the cellulose microfibrils. The total quantity of non-cellulosic polysaccharide in the Saprolegniaceae approaches 85% of the total wall weight in contrast with the situation in Vaucheria where the cellulose alone approaches 90% of the total cell wall. Dichotomosiphon is unique among the organism s studied in this paper, in possessing a cell wall entirely soluble in alkali and composed of approximately equal quantities of glucose and xylose. The crystalline component is aβ-1,3-linked xylan, as already reported for some of the Siphonales (closely related algae) by Frei & Preston.

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THE SIZE OF THE CELLULOSE MICROFIBRIL

The Journal of Cell Biology ◽

10.1083/jcb.17.1.105 ◽

1963 ◽

Vol 17 (1) ◽

pp. 105-109 ◽

Cited By ~ 31

Author(s):

J. Ross Colvin

Keyword(s):

Experimental Evidence ◽

Cellulose Microfibril ◽

Phosphotungstic Acid ◽

Negative Staining ◽

Cellulose Microfibrils ◽

Direct Experimental Evidence ◽

Native Cellulose ◽

Lateral Width ◽

The Difference

Recently the lateral width of the cellulose microfibril has been estimated as 30 A rather than about 150 to 200 A, by extrapolation of data from model shadowing experiments. The difference was attributed to a layer of metal deposited during shadowing. However, direct photographs of the same microfibrils parallel and perpendicular to the direction of shadowing, of unshadowed portions of microfibrils compared with shadowed portions of the same microfibrils, of silver-stained unshadowed microfibrils, and of unshadowed, unstained segments of microfibrils give no evidence of a layer of metal of this thickness in material shadowed under normal conditions. Furthermore, the evidence for microfibril strands of about 35 A in width from negative-staining experiments is subject to a bias from the form of the filaments and from variable positive adsorption of phosphotungstic acid by cellulose. Consequently, the conclusion that the true lateral width of native cellulose microfibrils is about one-fifth of the presently accepted value is not yet justified by unequivocal direct experimental evidence.

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Different Conformations of Surface Cellulose Molecules in Native Cellulose Microfibrils Revealed by Layer-by-Layer Peeling

Biomacromolecules ◽

10.1021/acs.biomac.7b01173 ◽

2017 ◽

Vol 18 (11) ◽

pp. 3687-3694 ◽

Cited By ~ 7

Author(s):

Ryunosuke Funahashi ◽

Yusuke Okita ◽

Hiromasa Hondo ◽

Mengchen Zhao ◽

Tsuguyuki Saito ◽

...

Keyword(s):

Cellulose Microfibrils ◽

Layer By Layer ◽

Native Cellulose ◽

Layer Peeling

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Unravelling the Mechanism of Stabilization and Microstructure of Oil-in-Water Emulsions by Native Cellulose Microfibrils in Primary Plant Cells Dispersions

ACS Applied Bio Materials ◽

10.1021/acsabm.8b00385 ◽

2018 ◽

Vol 1 (5) ◽

pp. 1440-1447 ◽

Cited By ~ 6

Author(s):

Emma M. Nomena ◽

Caroline Remijn ◽

Faranaaz Rogier ◽

Micah van der Vaart ◽

Panayiotis Voudouris ◽

...

Keyword(s):

Plant Cells ◽

Cellulose Microfibrils ◽

Native Cellulose ◽

Oil In Water

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A finger-jointing model for describing nanostructures of cellulose microfibrils

10.21203/rs.3.rs-145491/v1 ◽

2021 ◽

Author(s):

Bunshi Fugetsu ◽

Adavan Kiliyankil Vipin ◽

Shoichi Takiguchi ◽

Ichiro Sakata ◽

Morinobu Endo

Keyword(s):

Water Vapor ◽

Sustainable Development Goals ◽

Cellulose Nanofibers ◽

Cellulose Microfibrils ◽

Cellulose Nanowhiskers ◽

Saturated Water Vapor ◽

Native Cellulose ◽

Saturated Water ◽

Development Goals ◽

Finger Jointing

Abstract We propose a finger-jointing model to describe the possible nanostructures of native cellulose microfibrils based on new observations obtained through thermal decomposition of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidized cellulose nanofibers (CNFs) in saturated water vapor. We heated the micrometers-long TEMPO-CNFs in saturated water vapor (≥ 120 °C, ≥ 0.2 MPa) for ≤ 8 h. The long TEMPO-CNFs unzipped into short (100 s of nanometers long) cellulose nanowhiskers (CNWs). We characterized the CNWs using Raman spectroscopy and Fourier transform infrared spectroscopy, observing similar spectra as TEMPO-CNFs. Thus, the native cellulose microfibrils are not seamlessly long structures, but serial “jointed structures” of CNWs. The finger-jointing model implies a “working and resting rhythm” in the biosynthesis of cellulose. CNWs are highly dispersible in water and polar organic solvents, and are much easier to combine with other classes of polymers at nano-levels. The findings can enhance the feasibility and applicability of native cellulose to achieve sustainable development goals.

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Fasciaton of Pectate Elementary Fibrils

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070746 ◽

1973 ◽

Vol 31 ◽

pp. 60-61

Author(s):

George F. Leeper

Keyword(s):

Acid Treatment ◽

Carbon Film ◽

Final Concentration ◽

Cellulose Microfibrils ◽

Pectic Acid ◽

Elementary Fibrils

Polysaccharide elementary fibrils are usually fasciated into microfibrils of from one hundred to a few hundred Angstroms wide. Cellulose microfibrils when subjected to acid treatment dissociate into component elementary fibrils. For pectic acid it was observed that variations in pH could cause a change in the fasciation of the elementary fibrils.Solutions of purified pectic acid and sodium phosphotungtate were adjusted to various pH levels with NaOH or HCl and diluted to give a final concentration of 0.5 and 1% for the polysaccharide and negative stains respectively. Micrographs were made of the samples after drying on a carbon film covered grid. The average number of elementary fibrils was determined by counting the number of elementary fibrils in each fascicle intersected by lines drawn across the micrograph.

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A novel predictive method for filler coflocculation with cellulose microfibrils

TAPPI Journal ◽

10.32964/tj18.11.653 ◽

2019 ◽

Vol 18 (11) ◽

pp. 653-664

Author(s):

IGNACIO DE SAN PIO ◽

KLAS G. JOHANSSON ◽

PAUL KROCHAK

Keyword(s):

Negative Impact ◽

High Strength ◽

Strength Properties ◽

Cellulose Microfibrils ◽

Paper Strength ◽

Flow Loop ◽

Cationic Starch ◽

Reflectance Measurement ◽

Drainage Rate ◽

Complete Study

Different strategies aimed at reducing the negative impact of fillers on paper strength have been the objective of many studies during the past few decades. Some new strategies have even been patented or commercialized, yet a complete study on the behavior of the filler flocs and their effect on retention, drainage, and formation has not been found in literature. This type of research on fillers is often limited by difficulties in simulating high levels of shear at laboratory scale similar to those at mill scale. To address this challenge, a combination of techniques was used to compare preflocculation (i.e., filler is flocculated before addition to the pulp) with coflocculation strategies (i.e., filler is mixed with a binder and flocculated before addition to the pulp). The effect on filler and fiber flocs size was studied in a pilot flow loop using focal beam reflectance measurement (FBRM) and image analysis. Flocs obtained with cationic polyacrylamide (CPAM) and bentonite were shown to have similar shear resistance with both strategies, whereas cationic starch (CS) was clearly more advantageous when coflocculation strategy was used. The effect of flocculation strategy on drainage rate, STFI formation, ash retention, and standard strength properties was measured. Coflocculation of filler with CPAM plus bentonite or CS showed promising results and produced sheets with high strength but had a negative impact on wire dewatering, opening a door for further optimization.

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