Rate of Exchange of Cellulose with Heavy Water

Frilette, V. J.; Hanle, John.; Mark, H.

doi:10.1021/ja01183a071

Cited by 132 publications

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“…Such exchange can be investigated with D 2 O [24]. A recent infrared spectroscopic study of the H/D exchange in the I β polymorph of cellulose [11] indicates that water does not penetrate the hydrogen bond network except at the crystalline surfaces.…”

Section: Resultsmentioning

confidence: 99%

1H and 13C solid-state NMR of Gossypium barbadense (Pima) cotton

Taylor

French

Gamble

et al. 2008

Journal of Molecular Structure

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Abstract:The interaction of water with cellulose and its influence on the nuclear spin dynamics in Gossypium barbadense (Pima) C resonances from only the crystalline or the amorphous domains or from only the surface of the cellulose). However, spatial localization of the combined Goldman-Shen-13 C CP/MAS experiment using both short mixing and contact times yields a spectrum consistent with predominantly the I β polymorph of cellulose. Longer mixing times and the same, short contact time yield a spectrum that is indicative of an increased I α polymorph content in the crystallite interiors relative to the smaller values found with short mixing times.

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Section: Resultsmentioning

confidence: 99%

1H and 13C solid-state NMR of Gossypium barbadense (Pima) cotton

Taylor

French

Gamble

et al. 2008

Journal of Molecular Structure

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“…[3]) for the exchange equilibria between alcohols and deuterated water vary from 0.96 to 1.25 (22-28) ; of these the value of Hobdell et al (27) of 1.09 is probably the best. Although no data are available it is probable that similar effects exist for alcohols and tritiated water.…”

Section: Resultsmentioning

confidence: 99%

“…The ampoule, and a 2-g sample cut into strips about 7.5 cm wide and folded t o expose as much surface as possible, were placed into the reaction vessel (C). This was sealed, and then evacuated for a t least I 1 hours a t 70' C or for -13 hours a t room temperature, and then isolated by closi~lg valve F. T h e reaction was started by sha1;ing until the ampoule was broken by the plunger (D) and continued a t room telnperat~lre for an arbitrary period of 7 hours for amylopectin, and 1 hour for all other samples since this period was found adequate by other workers (3,9). lleanwhile the trap was assembled with the syringe, set to contain 0.2 ml, inside the centl-al tube (J) so that the needle rested in the bottom of the jacket (I<), and the isolated The water in the syringe was analyzed for tritium by the method of Robinson (15), i.e.…”

Section: R O H + I H T O = R O T + H ? O [ I ]mentioning

confidence: 99%

“…Deuterium has been used exteilsively as a tracer in the exchange of hydrogen isotopes between ccllulose and water (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11), but oilly the more recent studies of Frilette, Hanle, and RIIarl; ( 3 ) , 12linin ( 5 ) , and Mann and YIarrinan (S-11) are of value in accessibility studies. T h e excl~ange reaction, which was almost complete in 1 hour, was attributed t o exchange with the hydroxyl hydrogens of the cellulose i~ilits in the amorphous regions and 011 the faces ol the crystallites.…”

Section: Introductionmentioning

confidence: 99%

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Tritium Exchange Between Cellulose and Water: Accessibility Measurements and Effects of Cyclic Drying

Lang¹,

Mason²

1960

Can. J. Chem.

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Tritium exchange between cellulose and water vapor was used to measure the accessibilities of amylopectin, amylose, regenerated cellulose, \\,ood pulp, bacterial and Valonia cellulose, and cellulose trinitrate using both gas counting and solid counting techniques. The results compare satisfactorily with other accessibility and crystallinity measurements.The incomplete reversibility of the exchange reaction was used t o study directly changcs in the accessibility of regenerated cellulose which occurred during repeated wetting and drying from water. The res~llts indicated that a partial interchange of accessible and inaccessible regions occurs during wetting and drying. INTRODUCTIONThis paper describes-preliminary experiments which use the exchange reaction of tritium between ccllulose and water to s t i~d y the "accessibility" of cellulose to water vapor, and to measure directly the formation of ne\v inaccessible regions in cell~~lose during successive wetting ancl drying cycles.Deuterium has been used exteilsively as a tracer in the exchange of hydrogen isotopes between ccllulose and water (1-11), but oilly the more recent studies of Frilette, Hanle, and RIIarl; ( 3 ) , 12linin ( 5 ) , and Mann and YIarrinan (S-11) are of value in accessibility studies. T h e excl~ange reaction, which was almost complete in 1 hour, was attributed t o exchange with the hydroxyl hydrogens of the cellulose i~ilits in the amorphous regions and 011 the faces ol the crystallites. T h e ratio of the cell~~lose participating in the reaction to the total, calculatccl by assuming t h a t 3 hydroxyl groups reacted per runl~yclroglucose unit, was taken as a quailtitative measure of the accessibility. These accessibilities were in good agreement with other accessibility and crystallinity measureine~lts.111 the present work tritium (IH3), which, being raclioactive, has the aclvru~tage t h a t it ma), be easily, accurately, ant1 sensitively cletermined, was introduced as a tracer i l l the exchange reaction R . O H + I H T O = R . O T + H ? O [ I ]where R.OH is a carbohydrate containing accessible hydroxyls. T h e extent of this reaction was used to determine the accessibility of the carbohydrate. Measurements were made on a variety of salnples in two ways. 1. By a gas counting techilique in which cellulose ancl tritiated water v,~poi-werc I-eactecl together, ancl the adsorbed and vapor-phase water relnoved ancl analyzed by gas counting. T h e extent of the reaction was calculatecl from the stoichiometi-y of the system and the clilution of the tritium in the water.2. X raclioactivity counting method for solitl samples was used in \?ihirh cell~ilosc \vas cxch,lnged with tl-itiated water vapor. the water removed, ant1 the tcitiuin i l l the cellulose measured by c o u~~t i~i g the ~olicl sample. This neth hod required a special appal-atus, the \ 7 a c~~~~m Transfer C o~~n t e r (VTC), describecl else\vhere (12). T h e gas counting inctl~ocl was iisecl chiefly for calibration ancl corrol~ol-atio11 ol the solid counting n~ethocl.

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“…Since the technique of hydrogen-deuterium exchange has been improved to the point where it can be used to measure accessibility (9,10,22), and the values of accessibility so obtained on cotton linters are numeric all^ much greater than those obtained by the thallous ethylate procedure (lo), it was felt that this method might show greater differences between the members of a series of wetted and dried linters samples. However, the differences were again found to be small but still following the pattern observed before (Table IV, Figs.…”

Section: Discussionmentioning

confidence: 99%

The Reactivity of Cellulose: II.WATER Sorption, Heats of Wetting, and the Reactions With Thallous Ethylate in Ether, Nitration Mixtures, and Heavy Water of Cotton Linters Alternately Wetted With Water and Dried

Brickman¹,

Dunford²,

Tory³

et al. 1953

Can. J. Chem.

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Cotton linters dewaxed with benzene and alcohol possess a slightly expanded structure attributed to the swelling effect of the alcohol. Storage causes a partial collapse of the linters especially so when moisture is present. Wetting with water followed by rigorous drying produces a marked reduction in accessibility, but with each additional wetting-drying cycle accessibility of the dried linters increases slightly as measured by reaction with thallous ethylate in ether, a nitration mixture, and in hydrogen-deuterium exchange. Differences in nitration found for limited reaction times are obliterated when these reaction times are extended. Increasing accessibility due to repeated wetting and drying is accon~panied by lower water sorption and smaller heats of wetting. This anomaly is due to the fact that cellulose sanlples obtained by alternately wetting and drying dewaxed linters, when stored with a desiccant, compete for the limited amount of water present and adsorb moisture in proportion to their accessibility. Upon further exposure to water the sample of least accessibility, having adsorbed less water, can now adsorb to a greater extent than do the linters of somewhat greater accessibility.The evidence indicates that the difference in accessibility occasioned by repeated wetting and drying is of a physical rather than chemical nature. INTRODUCTIONThe accessibility of cellulose to reagents is a matter of colisiderable practical and theoretical importance and in recent years has been given a great deal of attention (6,12,16,19,21,28). I t has been shown quite conclusively that this accessibility is influenced by the previous history of the cellulose sufficiently that uniform reactivity is obtained only by the observation of great care in the choice and processing of the raw material (14, 25).The association of cellulose with water throughout most of its history has provoked enquiries regarding the influence that water has upon the properties of cellulose. I t is generally believed that water itself exercises only a swelling effect, producing nothing more than an increase in the amount of accessible cellulose a t the expense of that portion less highly organized. However, recent work indicates that a slight change in dimensions of the unit cell occurs when dry mercerized ramie, spun viscose, or regenerated acetate fibers are wetted (15). Furthermore, lengthy exposure of wet cellulose t o oxygen (air) or ozone is reported to produce some degradation of the macromolecule (3,4). The removal of water from cellulose by direct drying methods is accompanied by a decrease 1 n/Ia?~uscript

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Rate of Exchange of Cellulose with Heavy Water

Cited by 132 publications

References 0 publications

1H and 13C solid-state NMR of Gossypium barbadense (Pima) cotton

1H and 13C solid-state NMR of Gossypium barbadense (Pima) cotton

Tritium Exchange Between Cellulose and Water: Accessibility Measurements and Effects of Cyclic Drying

The Reactivity of Cellulose: II.WATER Sorption, Heats of Wetting, and the Reactions With Thallous Ethylate in Ether, Nitration Mixtures, and Heavy Water of Cotton Linters Alternately Wetted With Water and Dried

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