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Ono, Hideki; Yamada, Hiroyuki; Matsuda, Shigenobu; Okajima, Kunihiko; Kawamoto, Tomoaki; Iijima, Hideki

doi:10.1023/a:1009216015529

Cited by 28 publications

(16 citation statements)

References 9 publications

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“…An aqueous suspension of MCC similarly is highly thixotropic. 5 TCG-1.5 should have very large zero-shear viscosity scince the peak top value ( max ) on the vs. _ plot can be regarded as an approximate value of a viscosity under zeroshear condition.…”

Section: Rheological Properties Of Tcgmentioning

confidence: 99%

“…5 This is explained by averaging of T 2 based on the faster exchange of water molecules between the phases of free water and bound water in comparison with a time scale ($100 ms) of NMR. 5,15 The very short T 2 for TCG is due to the contribution of the water strongly interacting with surface of cellulose particles (''bound water''). In the previous work 5 for aqueous MCC suspension, T 2 of water at 25 C in 2 wt % MCC/water suspension was 0.21-0.22 s, about twice the present TCG.…”

Section: Rheological Properties Of Tcgmentioning

confidence: 99%

“…5,15 The very short T 2 for TCG is due to the contribution of the water strongly interacting with surface of cellulose particles (''bound water''). In the previous work 5 for aqueous MCC suspension, T 2 of water at 25 C in 2 wt % MCC/water suspension was 0.21-0.22 s, about twice the present TCG. This suggests that the contribution of bound water is larger for TCG than for MCC suspension.…”

Section: Rheological Properties Of Tcgmentioning

confidence: 99%

“…Ono et al revealed 5 that 1 H NMR relaxation (spinspin relaxation time, T 2 ) analysis for water 6,7 is effective to elucidate the relationship between viscosity and dispersion state of particles in aqueous suspension of microcrystalline cellulose (MCC) having a rod-like figure with several micrometers in longitudinal length. 3,5,8 They concluded that T 2 of water critically reflects the relatively mild aggregation (association) state of MCC in the suspension.…”

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confidence: 99%

“…3,5,8 They concluded that T 2 of water critically reflects the relatively mild aggregation (association) state of MCC in the suspension. In the case of MCC suspension, the dispersion state of MCC could be observed directly by an optical microscope owing to relatively large size.…”

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confidence: 99%

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1H Spin–Spin Relaxation Time of Water and Rheological Properties of Cellulose Nanofiber Dispersion, Transparent Cellulose Hydrogel (TCG)

Ono

Shimaya

Sato

et al. 2004

Polym J

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ABSTRACT:A new type of hydrogel, transparent cellulose hydrogel (TCG), is the aqueous dispersion of cellulose nanofibers (microfibrils) 10 nm in width and several hundreds nanometers in extended fiber length, and shows unique rheological properties leading to unique applications. The rheological properties of TCG, especially their dependences on temperature were investigated through the spin-spin relaxation time (T 2 ) analysis in 1 H NMR for water in the systems. Viscosity under low shear stress and T 2 of water (being very short for T 2 value) were proved to be constant in a wide range of temperature (ca. 30-80 C). These results may be explained by two considerations that network in TCG gradually grows with increasing temperature but collapses by adding weak shear stress and that TCG gel has large amount of bound water. It was also confirmed that the ionic strength such as pH and NaCl concentration sensitively influences on rheological parameters. With increasing ionic strength, the network formation and the successive aggregation of microfibrils occur and both should be interpreted in terms of the electrostatic interaction between negative charge on a cellulose surface and cationic aqueous layer around it (i.e., electric double layer). [DOI 10.1295/polymj.36.684] KEY WORDS Cellulose / Hydrogel / Nanofiber / Microfibril / Rheology / Spin-Spin Relaxation Time / Network / We have already found a preparation method of a new type of hydrogel, transparent cellulose hydrogel (TCG, Figure 1a), an aqueous dispersion of cellulose microfibrils (degree of polymerization: ca. 40) having low crystallinity with about 10-15 nm in diameter and several hundred nanometers in extended length ( Figure 1b) and reported the results for its characterization and properties. 1,2 This new nanomaterial was prepared by downsizing by chemical (hydrolysis reaction) 3 and mechanical (smashing by a ultra high pressure homogenizer) techniques. Resultant cellulose microfibrils in TCG are flexible fibrous particles, i.e., ''nanofibers'', having nano-size diameter (Figure 1b) and show strong attractive interaction based on hydrogen bonding between hydroxyl groups localized densely on their surfaces, leading to quite unique rheological properties. In view of the application, four major unique properties of TCG are pointed out 2 as follows: 1) Rheological properties such as very high viscosity under the low share stress, a large thixotropic character and low fluctuation of rheological parameters in the range of ambient temperature to the higher temperature region, 2) Formation of transparent coating film on substrate materials by drying, 3) Formation of cellulose microspheres having average particle size of less than 5 mm by spray drying, and 4) Stabilizing ability as an additive for aqueous suspension systems such as aqueous dispersion of inorganic particles (SiO 2 , TiO 2 , . . ., etc.) and O/W type emulsion (also as an emulsifier).Especially from an industrially applicable aspect, we discovered that TCG is a gel which can be sprayed by only ...

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Section: Rheological Properties Of Tcgmentioning

confidence: 99%

Section: Rheological Properties Of Tcgmentioning

confidence: 99%

Section: Rheological Properties Of Tcgmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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1H Spin–Spin Relaxation Time of Water and Rheological Properties of Cellulose Nanofiber Dispersion, Transparent Cellulose Hydrogel (TCG)

Ono

Shimaya

Sato

et al. 2004

Polym J

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Amino Acids in Human and Animal Nutrition

Karau

Grayson

2014

Advances in Biochemical Engineering/Biotechnology

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Amino acids are key components of human and animal nutrition, both as part of a protein-containing diet, and as supplemented individual products. In the last 10 years there has been a marked move away from the extraction of amino acids from natural products, which has been replaced by efficient fermentation processes using nonanimal carbon sources. Today several amino acids are produced in fermentation plants with capacities of more than 100,000 tonnes to serve the requirements of animal feed and human nutrition. The main fermentative amino acids for animal nutrition are L-lysine, L-threonine, and L-tryptophan. DL-Methionine continues to be manufactured for animal feed use principally by chemical synthesis, and a pharmaceutical grade is manufactured by enzymatic resolution. Amino acids play an important role in medical nutrition, particularly in parenteral nutrition, where there are high purity requirements for infusion grade products. Amino acids are also appearing more often in dietary supplements, initially for performance athletes, but increasingly for the general population. As the understanding of the effects of the individual amino acids on the human metabolism is deepened, more specialized product mixtures are being offered to improve athletic performance and for body-building.

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