Longitudinal and concurrent dimensional changes of cellulose aggregate fibrils during sorption stages

Lee, Jung Myoung; Pawlak, Joel J.; Heitmann, John A.

doi:10.1016/j.matchar.2010.02.007

Cited by 23 publications

(28 citation statements)

References 25 publications

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“…All the samples were observed in nanodimensional rod-shape structure or needle-like nanoparticles. After the catalytic acid hydrolysis process, the original native cellulose long fibrils structure was successfully separated into smaller and finer fiber fragments (Lee et al 2010). The AFM images show that the average diameters of Cr(III)-treated nanocellulose fibers (64.1 ± 31.7 nm) were smaller than those of Mn(II)-treated nanocellulose fibers (80.9 ± 30.3 nm).…”

Section: Morphological Study (Afm Analysis)mentioning

confidence: 99%

Preparation of Nanostructured Cellulose via Cr(III)- and Mn(II)-Transition Metal Salt Catalyzed Acid Hydrolysis Approach

Chen¹,

Lee²,

Hamid³

2016

BioResources

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Nanostructured cellulose was successfully prepared from native cellulose using a homogeneous catalytic H2SO4 hydrolysis pathway in the presence of Cr(III)-and Mn(II)-transition metal salts as the co-catalyst. The effect of transition metal salts with different valence states (Cr 3+ and Mn 2+) on the physicochemical properties (chemical characteristics, crystallinity index, nano-structure, thermal stability, and morphology) of prepared nanocellulose was investigated. Interestingly, TEM micrographs showed that the Cr(III)-treated and Mn(II)-treated nanocellulose exhibited a weblike nanostructured-surface with average diameters of 44.7 ± 13.2 nm and 58.4 ± 15.3 nm, respectively. XRD study revealed that the crystallinity of nanocellulose was increased because the catalytic degradation of the less crystalline regions of cellulose occurred at a faster rate than its crystalline phases. Cr(III)-treated nanocellulose was capable of rendering a higher crystallinity index (75.6 ± 0.1%) compared with Mn(II)-treated nanocellulose (72.3 ± 0.4%). Furthermore, a dynamic light scattering (DLS) study revealed that Cr(III)-treated nanocellulose showed a smaller distribution range (92% at 14 to 135 nm) compared with Mn(II)-treated nanocellulose (92% at 607 nm). A higher valence state for the Cr(III)-cation, with a trivalent state (+3), rendered a more effective hydrolysis reaction compared with the Mn(II)-cation, with a divalent state (+2), for preparing the nanocellulose.

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Section: Morphological Study (Afm Analysis)mentioning

confidence: 99%

Preparation of Nanostructured Cellulose via Cr(III)- and Mn(II)-Transition Metal Salt Catalyzed Acid Hydrolysis Approach

Chen¹,

Lee²,

Hamid³

2016

BioResources

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“…For flax fibers, it can reach 25% in their transverse direction but rarely exceeds 0.2% in their longitudinal direction (Müssig, 2010). Hygroscopic strains are generally reversible but when they become substantial the micro-structure of cellulosic fibers undergo damage (Lee et al, 2010). Consequently, with such a significant macroscopic strain, it is very likely that flax fibers were damaged during the sorption and/or desorption process.…”

Section: Reversible and Irreversible Mechanismsmentioning

confidence: 99%

Reversible and irreversible changes in physical and mechanical properties of biocomposites during hydrothermal aging

Regazzi

Corn

Ienny

et al. 2016

Industrial Crops and Products

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The use of biocomposites on a daily basis for industrial products brings to light the influence of environmental factors on the evolution of mechanical properties. This aging has a major influence in the lifetime of any product based on such materials. Among biobased composites, poly(lactic acid) reinforced with plant fibers are known to be sensitive to hydrothermal aging due to the intrinsic nature of their components. Although some papers studied the influence of temperature and water absorption on such materials, so far the difference between reversible and irreversible effects of aging has been hardly studied. This distinction is the purpose of this study. Poly(lactic acid) samples reinforced with various content of flax fibers (0%, 10%, and 30%) were immersed in water at different temperature (20, 35, and 50°C) up to 51 days. The physical and chemical phenomena responsible for the changes in the mechanical properties of biocomposites were evaluated. It was observed that these changes were mainly reversible. However, irreversible effects of aging turned out to increase drastically with the amount of fiber and the aging temperature. While hydrolysis drastically deteriorated PLA for longer aging times, the lifetime of biocomposites was significantly extended (+ 230% at 50°C from 0% to 10% in fiber content) by the presence of fibers which postponed the failure of PLA.2

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“…Understanding the interactions between natural fibers and water is of great importance, because of the pronounced influence of moisture on their mechanical properties as well as on dimensional changes. 5,6 Therefore, the adhesion with hydrophobic matrix is not strong enough and the aging of composite materials reinforced by plant fibers can lead to a premature degradation and the loss of their mechanical properties. 7,8 Many practical investigations have been achieved to modify the structure of natural fibers in order to reduce their hydrophilic characteristic.…”

Section: Characterization and Modeling Of The Moisture Diffusion Behamentioning

confidence: 99%

Characterization and modeling of the moisture diffusion behavior of natural fibers

Célino¹,

Fréour²,

Jacquemin³

et al. 2013

J of Applied Polymer Sci

112

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HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

show abstract

Longitudinal and concurrent dimensional changes of cellulose aggregate fibrils during sorption stages

Cited by 23 publications

References 25 publications

Preparation of Nanostructured Cellulose via Cr(III)- and Mn(II)-Transition Metal Salt Catalyzed Acid Hydrolysis Approach

Preparation of Nanostructured Cellulose via Cr(III)- and Mn(II)-Transition Metal Salt Catalyzed Acid Hydrolysis Approach

Reversible and irreversible changes in physical and mechanical properties of biocomposites during hydrothermal aging

Characterization and modeling of the moisture diffusion behavior of natural fibers

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