The influence of wet/dry treatment on pore structure-the correlation of pore parameters, water retention and moisture regain values

Kongdee, Arunee; Bechtold, Thomas; Burtscher, Eduard; Scheinecker, Markus

doi:10.1016/j.carbpol.2004.03.025

Cited by 49 publications

(37 citation statements)

References 15 publications

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“…The Relationships among the WRV, Hydrogen Bond Models, and Supramolecular Structure of Deinked Fibers The Water Retention Value (WRV) is a general measure of fiber swelling capacity (Jayme 1958). 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).…”

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

confidence: 96%

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: 96%

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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“…15 The porous structure in ND changes with drying treatment, resulting in collapse of pores, and ND loses its large accessibilities of water and chemical substances. 16 The NSF and SF are ND fiber-dried, without and with spin-finishing. This means that NSD and SF were dried totally twice when they were treated with polym1, while ND was dried once.…”

Section: Resultsmentioning

confidence: 99%

Fibrillation tendency of cellulosic fibers, part 6: Effects of treatments with additive polymers

Zhang¹,

Okubayashi²,

Badura

et al. 2006

J of Applied Polymer Sci

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ABSTRACT:The influences of the treatments with various polymers on fibrillation and abrasion resistances of lyocell materials were investigated with respect to the type of polymer, the polymer concentration, and the drying temperature. Fibril number, generated with agitation using ball-bearings (FN ball ), was decreased with increasing the concentration of aminofunctional polysiloxane because of reduction in water retention capacity (WRV) in fibers. The never-dried lyocell fiber showed smaller decrease in FN ball because of its higher WRV when compared to dried fibers. The treatment with aminofunctional polysiloxane enhanced not only the fibrillation resistance but also abrasion resistance, which was indicated as rotation number of abrasive bar in the abrasion test (RN abr ). No fibrillation was obtained in the fiber treated with 10 g/L aminofunctional polysiloxane at 120°C for 20 min, while the fibers treated at 60 and 170°C for 15 min were fibrillated in the agitation and abrasion tests. The addition of secondary polyethylene derivative also reduced the fibrillation tendency of lyocell; however, the extent of the reduction was lesser when compared with aminofunctional polysiloxane. The treatments with polyacrylate, polyurethane, and polyisocyanate derivatives improved the fibrillation resistance in lyocell fabrics, while fiber abrasion resistance was not significantly improved by the treatment with those additives, except in polyisocyanate.

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“…[15] In essence, the material of interest is packed in a chromatography column to act as the stationary phase and probe molecules (substances of known molecular size that have no affinity for the material) are eluted through the column in a mobile phase. The pore parameters (total pore volume, pore surface area, and pore size) are derived from the elution profiles.…”

Section: Porositymentioning

confidence: 99%

Treatment in Swelling Solutions Modifying Cellulose Fiber Reactivity – Part 1: Accessibility and Sorption

Jaturapiree

Ehrhardt

Groner

et al. 2008

Macromolecular Symposia

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Summary: Of prime importance in reactions involving insoluble cellulosic fibers is the sorption of reagents, which is governed by their degrees of accessibility in substrates. Swelling treatments of cellulosics in alkali solutions alter substrate accessibility leading to changes in their reactivity. In this paper, the first of a two-part series, we collate and examine the results from various studies involving different techniques to characterize modifications in cellulosic fibers after swelling treatments in alkali solutions. Results from measurements of structure and accessibility in fibers with techniques such as water retention, inverse size exclusion chromatography (ISEC), iodine sorption, fiber diameters, and fiber-splitting propensities indicate that the influence of swelling treatments on fiber structure/accessibility is differs with alkali type. The results show that a non-uniform rather than uniform distribution of reagents within structures is a more accurate representation of reactions involving swollen cellulosic fibers. Hence, the observed changes in cellulose-fiber reactivity are governed by the degrees of fiber swelling, and reagent sorption and accessibility during swelling treatments.

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The influence of wet/dry treatment on pore structure-the correlation of pore parameters, water retention and moisture regain values

Cited by 49 publications

References 15 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

Fibrillation tendency of cellulosic fibers, part 6: Effects of treatments with additive polymers

Treatment in Swelling Solutions Modifying Cellulose Fiber Reactivity – Part 1: Accessibility and Sorption

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