Cellulose fibril aggregation — an inherent property of kraft pulps

Hult, Eva-Lena; Larsson, Per Tomas; Iversen, Tommy

doi:10.1016/s0032-3861(00)00774-6

Cited by 247 publications

(187 citation statements)

References 22 publications

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“…According to previous research, the hydrogen bond models and cellulose supramolecular structure (crystalline structure) greatly influence the WRV (Kongdee et al 2004;Khantayanuwong et al 2002b;Page and Tydeman 1963;Weise and Paulapuro 1999). For instance, with increasing recycling times, the decrease in the WRV might have been due to the formation of irreversible hydrogen bonds in the cellulose fibrils of the fibers, or to irreversible aggregation of cellulose microfibrils, or perhaps both factors (Matsuda et al 1994;Wistara and Yong 1999;Hult et al 2001). As always, the main reason accounting for these results is the structure of cellulose.…”

Section: Changes Of the Content Of Polymorphs And Cellulose Fibril Agmentioning

confidence: 99%

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Effects of Different Deinking Processes on Fiber Morphology, Hydrogen Bond Models, and Cellulose Supramolecular Structure

Meng

Wan

et al. 2013

BioResources

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Deinked pulp fibers produced by three kinds of deinking processes, alkaline deinking, neutral deinking, and enzymatic deinking, were studied by Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectrometer (FTIR), X-ray Diffraction (XRD), and CrossPolarization Magic Angle Spinning Carbon-13 Nuclear Magnetic Resonance (CP/MAS 13 C-NMR). There were remarkable differences in both macroscopic and microscopic structure between the samples. SEM images showed that the effects of deinking processes on fiber morphology were obvious and the influences of alkaline deinking were the most apparent. FTIR analysis indicated that the content of intermolecular hydrogen bonds increased by 22.63%, 9.42%, and 14.40% after the alkaline deinking process, neutral deinking process, and enzymatic deinking process, respectively. XRD revealed that the average width of crystallite size in the (002) lattice plane was decreased after different deinking processes, in accordance with the change tendency of cellulose crystallinity. CP/MAS 13 C NMR combined with spectral fitting demonstrated that the content of different cellulose polymorphs changed during deinking processes. The increase of WRV was attributed to changes in the hydrogen bonding patterns and cellulose supramolecular structure. Technology, Guangzhou 510640, PR China; c: School of Environmental Science and Engineering, South China University of Technology, Guangzhou 510006, PR China; *Corresponding author:mwizard@126.com Keywords INTRODUCTIONWith the demand of protecting forest resources and developing a low-carbon economy, secondary fiber recycling has aroused the attention of technologists throughout the world, and the rapid growth of the waste paper utilization has become an important trend of the world's paper industry. According to the statistics of the China Paper Association, the total consumption of pulp from wastepaper in the paper industry was 44.39 million tons in 2008 in China. In 2011 it increased to 56.60 million tons, accounting for 62% of total pulp consumption (China Paper Association). Recycled cellulose fiber accounted for about 70% of the papermaking materials by the end of the 20 th century (Wan and Ma 2004). This recycled material can help make up for an insufficient supply of fresh papermaking raw materials, can reduce energy consumption in comparison to the pulping of wood, and also can play an essential role in decreasing environmental pollution problems. Deinking is an important stage in secondary fiber PEER-REVIEWED ARTICLE bioresources.com Meng et al. (2013). "Hydrogen bonds & deinking," BioResources 8(2), 2398-2416. 2399recycling. Conventional deinking processes often employ sodium hydroxide in combination with a large amount of other chemicals, including sodium silicate, hydrogen peroxide, and surfactants (Shrinath et al. 1991). This high pH and chemical-intensive process leads to several major problems for the process and recycled paper quality, including a high degree of fragmentation of large sticky contaminants, darkening of pu...

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Section: Changes Of the Content Of Polymorphs And Cellulose Fibril Agmentioning

confidence: 99%

“…The overall procedure was repeated twice. Afterwards, the samples were hydrolyzed for 8 h in 2.5 M HCl at 100 °C (Hult et al 2001). Finally, the pulp samples were washed with deionized water to a pH of 4 to 5 prior to drying freely.…”

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confidence: 99%

Effects of Different Deinking Processes on Fiber Morphology, Hydrogen Bond Models, and Cellulose Supramolecular Structure

Meng

Wan

et al. 2013

BioResources

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“…As shown by Scallan (1966, 1968), the loss of absorbency upon drying of cellulose fibers generally can be attributed to a partly irreversible closure of submicroscopic pores. Strong capillary forces acting during the drying process (Campbell 1959) can pull the walls of some pores into close contact, and the regularity of the cellulose structure can result in a zipper-like formation of multiple, repeating hydrogen bonds, essentially causing the adjacent surfaces to coalesce into a single cellulosic entity (Hult et al 2001;Pönni et al 2012). Though additional refining has been shown to restore much of the bonding strength that is lost when kraft fibers are dried, the corresponding effects related to restoration of porosity tend to be more limited (Klungness and Caulfield 1982).…”

Section: Drying and Absorbencymentioning

confidence: 99%

Enhanced Absorbent Products Incorporating Cellulose and Its Derivatives: A Review

Hubbe¹,

Ayoub²,

Daystar³

et al. 2013

BioResources

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Cellulose and some cellulose derivatives can play vital roles in the enhancement of the performance of absorbent products. Cellulose itself, in the form of cellulosic fibers or nano-fibers, can provide structure, bulk, water-holding capacity, and channeling of fluids over a wide dimensional range. Likewise, cellulose derivatives such as carboxymethylcellulose (CMC) have been widely studied as components in superabsorbent polymer (SAP) formulations. The present review focuses on strategies and mechanisms in which inclusion of cellulose -in its various formscan enhance either the capacity or the rate of aqueous fluid absorption in various potential applications.

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“…Two C-4 signals at 84.3 and 83.3 ppm are assigned to cellulose at accessible fibril surfaces in contact with water and the C-4 signal at 83.8 ppm is assigned to cellulose at water-inaccessible fibril surfaces, formed either by interior distortions or aggregation of fibrils [32]. Paracrystalline cellulose can, at least in part, be explained by the presence of phase boundaries, such as the fibril-to-fibril contact surfaces.…”

Section: Cellulose I Fibril Aggregate Modelmentioning

confidence: 99%

“…There is a broad distribution of fibril aggregate structures in pulp probably due to the presence of hemicelluloses and short chain glucan in pulp samples. In order to calculate the average lateral fibril dimensions (LFD) and average lateral fibril aggregate dimensions (LFAD), spectral fitting has to be performed on lignin-and hemicellulose-free pulp samples (glucose content > 95 %) since interfering signals (signal overlap from hemicellulose and spinning side bands from the lignin) influence calculations [32]. From the assignment of the signals in the C-4 region of the CP/MAS 13 C-NMR spectra, lateral dimensions can be assigned.…”

Section: The Application Of Cp/mas 13 C-nmr For Determining Average Lmentioning

confidence: 99%

Supra-Molecular Structure and Chemical Reactivity of Cellulose I Studied Using CP/MAS 13C-NMR

Chunilall¹,

Bush²,

Larsson³

2013

Cellulose - Fundamental Aspects

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Cellulose fibril aggregation — an inherent property of kraft pulps

Cited by 247 publications

References 22 publications

Effects of Different Deinking Processes on Fiber Morphology, Hydrogen Bond Models, and Cellulose Supramolecular Structure

Effects of Different Deinking Processes on Fiber Morphology, Hydrogen Bond Models, and Cellulose Supramolecular Structure

Enhanced Absorbent Products Incorporating Cellulose and Its Derivatives: A Review

Supra-Molecular Structure and Chemical Reactivity of Cellulose I Studied Using CP/MAS 13C-NMR

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