| 1. |
- Aad, G., et al.
(författare)
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- 2012
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swepub:Mat__t (refereegranskat)
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| 2. |
- Jia, Ning, et al.
(författare)
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Hydrothermal fabrication, characterization, and biological activity of cellulose/CaCO3 bionanocomposites
- 2012
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617 .- 1879-1344. ; 88:1, s. 179-184
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Tidskriftsartikel (refereegranskat)abstract
- Bionanocomposites with the combination of natural polymers and inorganic nanoparticles may induce unique properties and exhibit promising functions for different applications. Herein, we report a hydrothermal route to the preparation of cellulose/CaCO3 bionanocomposites using the cellulose solution. Ca(NO3)(2)center dot 4H(2)O and Na2SiO3 center dot 9H(2)O. The cellulose solution was previously prepared by the dissolution of microcrystalline cellulose in NaOH-urea aqueous solution. The urea also acts as the CO32- source for the synthesis of CaCO3. The influences of several reaction parameters, such as the heating time, the heating temperature, and the types of additives on the products were investigated by X-ray powder diffraction, Fourier transform infrared spectrometry, scanning electron microscopy, thermogravimetric analysis, and differential thermal analysis. The experimental results demonstrated that the hydrothermal conditions had an effect on the morphology of the bionanocomposites. Cytotoxicity experiments indicated that the cellulose/CaCO3 bionanocomposites had good biocompatibility, so that the bionanocomposites could be ideal candidate for practical biomedical applications.
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| 3. |
- Ma, Ming-Guo, et al.
(författare)
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Isolation and characterization of hemicelluloses extracted by hydrothermal pretreatment
- 2012
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Ingår i: Bioresource Technology. - : Elsevier BV. - 0960-8524 .- 1873-2976. ; 114, s. 677-683
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Tidskriftsartikel (refereegranskat)abstract
- The dewaxed sample from Triploid of Populus tomentosa Carr. was extracted by using organic alkaline solvent (Dimethylformamide, DMF) via hydrothermal pretreatment. Neutral sugar compositions and molecular weight analysis demonstrated that the hemicellulosic fractions with a higher Uro/Xyl ratio, namely the more branched hemicelluloses, had higher molecular weights. Interestingly, these results were different from the previous report, in which the ratio of Uro/Xyl in the water-soluble hemicellulosic fraction was more than that of the alkali-soluble hemicellulosic fraction. Spectroscopy (FUR, H-1 NMR, C-13 NMR, and HSQC) analysis indicated that the hemicellulosic fractions were mainly composed of (1 -> 4)-linked alpha-D-glucan from starch and (1 -> 4)-linked beta-D-xylan attached with minor amounts of branched sugars from hemicelluloses. In addition, thermal analysis implied that linear hemicelluloses showed more thermal stability than the branched ones during pyrolysis.
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| 4. |
- Ma, Ming-Guo, et al.
(författare)
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Nanocomposites of cellulose/iron oxide : influence of synthesis conditions on their morphological behavior and thermal stability
- 2012
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Ingår i: Materials science & engineering. C, biomimetic materials, sensors and systems. - : Elsevier BV. - 0928-4931 .- 1873-0191. ; 32:6, s. 1511-1517
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Tidskriftsartikel (refereegranskat)abstract
- Nanocomposites of cellulose/iron oxide have been successfully prepared by hydrothermal method using cellulose solution and Fe(NO3)(3)center dot 9H(2)O at 180 degrees C. The cellulose solution was obtained by the dissolution of microcrystalline cellulose in NaOH/urea aqueous solution, which is a good system to dissolve cellulose and favors the synthesis of iron oxide without needing any template or other reagents. The phases, microstructure, and morphologies of nanocomposites were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectra (EDS). The effects of the heating time, heating temperature, cellulose concentration, and ferric nitrate concentration on the morphological behavior of products were investigated. The experimental results indicated that the cellulose concentration played an important role in both the phase and shape of iron oxide in nanocomposites. Moreover, the nanocomposites synthesized by using different cellulose concentrations displayed different thermal stabilities.
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