Oriented cellulose films and fibers from a mesophase system

Chanzy, H.; Péguy, A.; Chaunis, S.; Monzie, P.

doi:10.1002/pol.1980.180180517

Cited by 191 publications

(73 citation statements)

References 8 publications

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“…Basically NOC was prepared by stretching a water-swollen cellulose film that had been coagulated from a dimethylacetamide͞LiCl solution. Dissolution of cellulose and preparation of the template was accomplished by a previously described procedure (4) using a solvent exchange technique (12). Strips Ϸ30 mm long and 5 mm This paper was submitted directly (Track II) to the PNAS office.…”

Section: Methodsmentioning

confidence: 99%

Biodirected epitaxial nanodeposition of polymers on oriented macromolecular templates

Kondo

Nojiri

Hishikawa

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

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Biodirected epitaxial nanodeposition of polymers was achieved on a template with an oriented molecular surface. Acetobacter xylinum synthesized a ribbon of cellulose I microfibrils onto a fixed, nematic ordered substrate of glucan chains with unique surface characteristics. The substrate directed the orientation of the motion due to the inverse force of the secretion during biosynthesis, and the microfibrils were aligned along the orientation of the molecular template. Using real-time video analysis, the patterns and rates of deposition were elucidated. Field emission scanning electron microscopy revealed that a strong molecular interaction allowed for the deposition of nascent biosynthesized 3.5-nm cellulose microfibrils with inter-microfibrillar spacings of 7-8 nm on the surface of the template. The cellulose was deposited parallel to the molecular orientation of the template. Directed cellulose synthesis and ordered movement of cells were observed only by using a nematic ordered substrate made from cellulose, and not from ordered crystalline cellulose substrates or ordered cellulose-related synthetic polymers such as polyvinyl alcohol. This unique relationship between directed biosynthesis and the ordered fabrication from the nano to the micro scales could lead to new methodologies for the design of functional materials with desired nanostructures. Interfacial surface structure and interaction of materials at the nanoscale have attracted much attention in the field of nanotechnology (1). Microbiological systems have been investigated as a microscale process (2); however, recent studies showing the unique interaction of biological systems with entirely synthetic molecular assemblies have prompted consideration of a new generation of approaches for controlled nanoassembly (3). We report on an interaction of a biological system with an artificially oriented molecular substrate. The preparation of such an ordered substrate recently was achieved by Kondo and coworkers (4, 5) by dissolving native cellulose and reprecipitating it in a unique manner to form a distinctive structure termed nematic ordered cellulose (NOC) (Fig. 1). This is a unique type of glucan chain association. The structure is highly ordered but not crystalline and therefore may have exclusive properties as a material product over the native form of crystalline cellulose. The unique surface of NOC can be used as a template for the construction of nanocomposites. The methods for producing NOC also have been applied to other biopolymers, e.g., chitin, xylan, their derivatives, and blends of these polymers, and these will be reported in future papers.Native biopolymer assembly has been shown to be a complex process involving two separate, but integrated, steps of polymerization and crystallization (6). In particular, cellulose has been shown to be assembled by a macromolecular complex of enzymes located on the cell surface (7). Nature has designed an efficient system for regulating the molecular weight, crystallinity, size, and shape of the nanostruct...

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Section: Methodsmentioning

confidence: 99%

Biodirected epitaxial nanodeposition of polymers on oriented macromolecular templates

Kondo

Nojiri

Hishikawa

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

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“…8 The cellulose solutions in anhydrous NMMO crystallize at lOO'C, producing a cellulated structure. 8 Chanzy et al 9 and Navard and Haudin 15 observed a phase transition from anisotropic to isotropic takes place at the range from 88 to 90'C from the rheological measurement of cellulose (DPw 900) solutions in NMMO hydrates with n, range from 0.3 to 0.54, which hydrates were prepared by simple mixing of anhydrous NMMO and water. Referring to our result for NMMO hydrates with n, range from 0.45 to 0.65 the secondary and the third crystallization takes place in the range from 80 to 120'C.…”

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confidence: 99%

Effect of Thermal History on the Phase Behavior of N-Methyl Morpholine N-Oxide Hydrates and Their Solutions of Cellulose

Kim

Lee

et al. 2001

Polym J

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ABSTRACT:N-Methyl morpholine N-oxide (NMMO) hydrates, used in the preparation of cellulose spinning dope for lyocell manufacturing, have various crystal structures according to the hydration number (n ). A single melting peak for solid-solid transition from NMMO monohydrate to anhydrous NMMO at 94 oC was previously reported. However, we observed the melting peak at 90'C ascribed to the solid-solid transition from NMMO monohydrate to anhydrous NMMO and another melting peak observed in the range from 98 to 105'C when n < 1. This discrepancy resulted from the experimental errors in differential scanning calorimetry (DSC) measurement. The pressure capsule enabled us to obtain precise and reproducible DSC data ofNMMO hydrates. The three different crystal structures ofNMMO hydrates with n < 1 were identified by crystallization experiments. The crystal, which had melted in the range from 90 to 105°C during heating (shown by double peaks), was recrystallized at SOOC during cooling, which has never been reported. The NMMO hydrates with n < 1 required heating above 130'C to produce a homogeneous melt, and the required temperature was increased up to 180'C for anhydrous NMMO. If the heating temperature was not high enough to fully melt the NMMO hydrate crystal, the unmelted NMMO hydrate crystals affected the thermal responses of the hydrate and its phase behavior of cellulose solutions in the NMMO hydrate.KEY Recently the N -methyl morpholine N -oxide (NMMO) hydrates attract much attention of cellulose processors because it is a versatile solvent of cellulose in the commercial production of lyocell fibers and cellulose films by direct dissolution method. 1 -9 They dissolve cellulose through hydrogen bonding by the N-O group ofNMMO. Anhydrous NMMO best dissolves cellulose but unfavorable as the solvent because of high melting temperature (T m) 172°C, which readily causes the thermal degradation. The T m and solvating power of NMMO hydrate are dependent on the value of n. 10 -13 Commercial lyocell spinning generally adopts solutions of cellulose in NMMO hydrates with n, range from 0 to 1.0.The value ofn ofNMMO hydrates has a significant influence on the phase behavior of the cellulose solutions.9·14 The NMMO hydrates with n = 1-1.5 are reported to produce isotropic cellulose solutions and anisotropic solutions are recognized to be obtained by using the NMMO hydrates with n < 1. Up to now, however, the reason for the phase behavior of the cellulose solutions with the value of n is not clear although some rheological attempts were made to account for the phenomenon. l5-17 It is prerequisite to characterize the thermal properties of NMMO hydrates to obtain a precise phase diagram of the cellulose solutions with the value of n. Lots of thermal analyses on the NMMO hydrates have been carried out to understand the phase behavior of the solution.8·9·18-23 A careful examination of their experimental conditions raises questions about the reproducibility of results. They prepared NMMO hydrates with n::; 1 by heating the simple mixt...

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“…But solvents were very limited in metal complexes, strong acids and salts, due to highly developed intra-and intermolecular hydrogen bonds in cellulose solid. 1 For these thirty years, new organic and inorganic solvents, such as N,N-dimethylacetamide (DMAc)jlithium chloride (LiC1) 2 • 3 and amine oxide containing water, 4 liquid ammonia/ammonia thiocyanate, 5 • 6 and aqueous (aq) sodium hydroxide (NaOHf- 9 have been found and the dissolving mechanisms of cellulose into these solvents have been intensively investigated. For some solvents, the solubility of cellulose is exclusively governed by the structure of cellulose solid.…”

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confidence: 99%

Solubility and Dissolved Cellulose in Aqueous Calcium- and Sodium-Thiocyanate Solution

Hattori

Shimaya

Saito

1998

Polym J

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ABSTRACT:Attempt was made to investigate the solubility and the dissolved state of various cell uloses in aqueous (aq) calcium-and sodium-thiocyanate solution. Almost all cell uloses used in this study were soluble in 55 wt% aq calcium thiocyanate (Ca(SCN) 2) soln. at about 100°C, while 60wt% aq sodium thiocyanate (NaSCN) soln. dissolves only limited cellulose mainly regenerated from cellulose solution. The solubility of cellulose in 60wt% aq NaSCN was independent of the crystal form, crystallinity and the degree of polymerization of cellulose and this was explained only in terms of the degree of breakdown of intramolecular hydrogen bonds in the cellulose solid. Using 2-dimensional NMR six carbon peaks in 13 C NMR spectra of cellulose in two solvents were successfully assigned. The comparison of chemical shifts of cellulose in 55 wt% aq Ca(SCN)2 solution and 10% sodium hydroxide (NaOH) solution strongly suggested that calcium atoms as electron acceptors coordinate with oxygen atoms in glucose ring and primary alcohol at C(6) position, in the same manner of cellulose dipped in 55 wt% aq Ca(SCN)z solution at room temperature. In the 13 C NMR spectrum of cellulose-60% aq NaSCN solution system, C(3), C(2), and C(6) peaks were observed at lower magnetic field side, implying that sodium atoms interact with hydroxide groups at C(2), C(3), and C(6) positions of glucopyranose in cellulose molecules.

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Oriented cellulose films and fibers from a mesophase system

Cited by 191 publications

References 8 publications

Biodirected epitaxial nanodeposition of polymers on oriented macromolecular templates

Biodirected epitaxial nanodeposition of polymers on oriented macromolecular templates

Effect of Thermal History on the Phase Behavior of N-Methyl Morpholine N-Oxide Hydrates and Their Solutions of Cellulose

Solubility and Dissolved Cellulose in Aqueous Calcium- and Sodium-Thiocyanate Solution

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