Hydrogen Bond and Crystal Deformation of Cellulose in Sub/Super-critical Water

Ito, Takahiro; Hirata, Yoshihiro; Sawa, Fumio; Shirakawa, Noriyuki

doi:10.1143/jjap.41.5809

Cited by 10 publications

(11 citation statements)

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“…Experimental evidence exists for this from Sasaki et al (2004) as discussed below. Further, Ito et al (2002) found that the population of hydrogen bonds between cellulose chains decreases with increasing water density. This would support our observation that increasing water density above a certain density value causes the dissolution temperatures to increase.…”

Section: Discussion On Dissolution Processesmentioning

confidence: 99%

“…In simulations, Ito et al (2002) studied small (54 glucose units) arrangements of monoclinic crystalline cellulose of Ib phase in subcritical and SCW at densities of 310, 880, and 1000 kg/m 3 . Those authors found that the population of hydrogen bonds between cellulose chains decreases to half as the temperature increases from room temperature to about 475°C.…”

Section: Discussion On Dissolution Processesmentioning

confidence: 99%

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Direct observation of cellulose dissolution in subcritical and supercritical water over a wide range of water densities (550–1000 kg/m3)

et al. 2005

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Direct observations of the heating of microcrystalline cellulose (230 DP) in water at temperatures up to 410°C and at pressures up to 700 MPa were made with a batch-type microreactor. Cellulose particles were found to dissolve with water over temperatures ranging from 315 to 355°C at high pressures. Dissolution temperatures depended on water density and decreased from about 350°C at a water density of 560 kg/m 3 to a minimum of around 320°C at a water density of 850 kg/m 3 . At densities greater than 850 kg/m 3 , the dissolution temperatures increased and reached a value of about 347°C at 980 kg/m 3 . The cellulose dissolution temperatures were independent of heating rates for values ranging from 10 to 17°C/s. The low dependence of dissolution temperatures on the heating rates is strong evidence for simultaneous dissolution and reaction of the cellulose. Different phenomena occurred depending on water density. At low densities, particles turned transparent and seemed to dissolve into the aqueous phase from the surface. From 670 to 850 kg/m 3 , the cellulose particles visibly swelled just before completely collapsing and dissolving into the aqueous phase. The swelling probably increased water accessibility and particle surface area and thus lead to the lower dissolution temperatures observed. From 850 to 1000 kg/m 3 , the particles required longer times to dissolve and many fine brown-like particles were generated as the particles dissolved. FT-IR spectra of the residues were analyzed. Residues formed from heating cellulose at high densities still retained some cellulose character whereas those as low densities had little cellulose character, especially in the O -H stretching vibration region.

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Section: Discussion On Dissolution Processesmentioning

confidence: 99%

Section: Discussion On Dissolution Processesmentioning

confidence: 99%

Direct observation of cellulose dissolution in subcritical and supercritical water over a wide range of water densities (550–1000 kg/m3)

et al. 2005

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“…Water evaporated more readily from the NCC/ water solution than from the Res.-CBD-NCC/water solution. This finding is somewhat surprising due to the strong hydrogen bonds between NCC hydroxyl groups and the water molecules (Ito et al 2002). At the same time, the specific binding of Res.-CBD to NCC, as well as its chemical bonding with epoxide groups at the droplet interface, may be the base of the slower rate of evaporation.…”

Section: Resultsmentioning

confidence: 99%

Insertion of nano-crystalline cellulose into epoxy resin via resilin to construct a novel elastic adhesive

et al. 2014

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Development of high-performance bionanocomposite adhesives is of high interest due to their environmentally friendly nature and superior mechanical properties in outdoor environments. Nano-crystalline cellulose (NCC) and resilin are among the most promising bio-nanofillers, providing strength and elasticity, respectively. A novel bionanocomposite comprised of NCC and resilin fused to a cellulose binding domain (Res.-CBD) is presented. As a case study, commercial epoxy adhesive was chosen as a matrix for the bio-nanocomposite adhesive. Insertion of hydrophilic NCC into hydrophobic resins, such as epoxy, is typically performed using solvent exchange, chemical modification, emulsifier addition or mixing with water-borne resins, techniques which either limit the material's application range or which are considered environmentally unfriendly. The unique approach presented here employed Res.-CBD as a surfactant-like agent supportive of the direct insertion of water-suspended NCC into an epoxy resin. The presented approach involves binding of Res.-CBD to NCC through its CBD domain and a chemical reaction between the resin epoxide groups and Res.-CBD amine moieties. The resulting bio-nano material shows a 50 % increase in the Young's modulus and a 20 % decrease in the tan(d), compared to pristine epoxy. This novel epoxy adhesive can be advantageous in applications where higher elasticity and Young's modulus are required.

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“…It implies that cellulose I␣ occupied more proportion in the residue of waste paper sample 5 which crystallinity was lower than the other samples'. The crystalline allomorphs structure of cellulose I␤ was more stable than that of cellulose I␣ (Ito et al, 2002). The relative content of cellulose I␤ was higher in sample 1 with high crystallinity and this improved the stability of cellulose structure.…”

Section: Mircostructure Changes Of Waste Paper Fiber After Conversionmentioning

confidence: 90%

“…As is shown in the some research works, the crystallinity of cellulose is increased during the recycle process (Chen, Wang, Wan, & Ma, 2010), the fibrils appear to aggregate and form a more compact structure when the hemicellulose is removed, which led to the inaccessibility of fiber for reaction (Wan, Wang, & Xiao, 2010). The distorted cellulose and small initial amount of cellulose I␣ were converted to cellulose I␤ (Hult, Iversen, & Sugiyama, 2003) which is more stable in the cellulose crystalline allomorphs (Ito, Hirata, Sawa, & Shirakawa, 2002). If we can evaluate the cellulose supramolecular changes and the further effect on the conversion property of waste paper in HCW, it will help to create a way to improve the waste paper conversion efficiency in HCW.…”

Section: Introductionmentioning

confidence: 99%

A supramolecular structure insight for conversion property of cellulose in hot compressed water: Polymorphs and hydrogen bonds changes

Wang

Lian

Wan

et al. 2015

Carbohydrate Polymers

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Hydrogen Bond and Crystal Deformation of Cellulose in Sub/Super-critical Water

Cited by 10 publications

References 1 publication

Direct observation of cellulose dissolution in subcritical and supercritical water over a wide range of water densities (550–1000 kg/m3)

Direct observation of cellulose dissolution in subcritical and supercritical water over a wide range of water densities (550–1000 kg/m3)

Insertion of nano-crystalline cellulose into epoxy resin via resilin to construct a novel elastic adhesive

A supramolecular structure insight for conversion property of cellulose in hot compressed water: Polymorphs and hydrogen bonds changes

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