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Effects of Moisture on Diffusion in Unmodified Wood Cell Walls: A Phenomenological Polymer Science Approach. FORESTS 2019. [DOI: 10.3390/f10121084] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Despite the importance of cell wall diffusion to nearly all aspects of wood utilization, diffusion mechanisms and the detailed effects of moisture remain poorly understood. In this perspective, we introduce and employ approaches established in polymer science to develop a phenomenological framework for understanding the effects of moisture on diffusion in unmodified wood cell walls. The premise for applying this polymer-science-based approach to wood is that wood polymers (cellulose, hemicelluloses, and lignin) behave like typical solid polymers. Therefore, the movement of chemicals through wood cell walls is a diffusion process through a solid polymer, which is in contrast to previous assertions that transport of some chemicals occurs via aqueous pathways in the cell wall layers. Diffusion in polymers depends on the interrelations between free volume in the polymer matrix, molecular motions of the polymer, diffusant dimensions, and solubility of the diffusant in the polymer matrix. Because diffusion strongly depends on whether a polymer is in a rigid glassy state or soft rubbery state, it is important to understand glass transitions in the amorphous wood polymers. Through a review and analysis of available literature, we conclude that in wood both lignin and the amorphous polysaccharides very likely have glass transitions. After developing and presenting this polymer-science-based perspective of diffusion through unmodified wood cell walls, suggested directions for future research are discussed. A key consideration is that a large difference between diffusion through wood polymers and typical polymers is the high swelling pressures that can develop in unmodified wood cell walls. This pressure likely arises from the hierarchical structure of wood and should be taken into consideration in the development of predictive models for diffusion in unmodified wood cell walls.
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Sahputra IH, Alexiadis A, Adams MJ. Effects of Moisture on the Mechanical Properties of Microcrystalline Cellulose and the Mobility of the Water Molecules as Studied by the Hybrid Molecular Mechanics-Molecular Dynamics Simulation Method. ACTA ACUST UNITED AC 2019. [DOI: 10.1002/polb.24801] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Iwan H. Sahputra
- School of Chemical Engineering; University of Birmingham; Birmingham United Kingdom
| | - Alessio Alexiadis
- School of Chemical Engineering; University of Birmingham; Birmingham United Kingdom
| | - Michael J. Adams
- School of Chemical Engineering; University of Birmingham; Birmingham United Kingdom
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Fotie G, Rampazzo R, Ortenzi MA, Checchia S, Fessas D, Piergiovanni L. The Effect of Moisture on Cellulose Nanocrystals Intended as a High Gas Barrier Coating on Flexible Packaging Materials. Polymers (Basel) 2017; 9:polym9090415. [PMID: 30965717 PMCID: PMC6418864 DOI: 10.3390/polym9090415] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 08/29/2017] [Accepted: 08/30/2017] [Indexed: 12/04/2022] Open
Abstract
Cellulose nanocrystals (CNCs) exhibit outstanding gas barrier properties, which supports their use as a biobased and biodegradable barrier coating on flexible food packaging materials. As highly hydrophilic biopolymers, however, CNCs have a strong sensitivity to water that can be detrimental to applications with fresh foods and in moist conditions due to the loss of barrier properties. In this work, the oxygen and water vapor permeability of polyethylene terephthalate (PET) films coated with CNCs obtained from cotton linters were measured at varying levels of relative humidity, both in adsorption and desorption, and from these data, the diffusion and solubility coefficients were estimated. Therefore, the characterization of CNCs was aimed at understanding the fundamentals of the water-CNCs interaction and proposing counteractions. The CNCs’ moisture absorption and desorption isotherms at 25 °C were collected in the range of relative humidity 0–97% using different techniques and analyzed through GAB (Guggenheim-Anderson-de Boer) and Oswin models. The effects of moisture on the water status, following the freezable water index, and on the crystal structure of CNCs were investigated by Differential Scanning Calorimetry and by X-ray Powder Diffraction, respectively. These findings point to the opportunity of coupling CNCs with hydrophobic layers in order to boost their capabilities as barrier packaging materials.
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Affiliation(s)
- Ghislain Fotie
- DeFENS-Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, Via Celoria 2, Milano 20133, Italy.
| | - Riccardo Rampazzo
- Department of Chemistry, Università degli Studi di Milano, Via Golgi 19, Milano 20133, Italy.
- CRC Laboratorio di Materiali e Polimeri (LaMPo), Department of Chemistry, Università degli Studi di Milano, Via Golgi 19, Milano 20133, Italy.
| | - Marco Aldo Ortenzi
- Department of Chemistry, Università degli Studi di Milano, Via Golgi 19, Milano 20133, Italy.
- CRC Laboratorio di Materiali e Polimeri (LaMPo), Department of Chemistry, Università degli Studi di Milano, Via Golgi 19, Milano 20133, Italy.
| | - Stefano Checchia
- Department of Chemistry, Università degli Studi di Milano, Via Golgi 19, Milano 20133, Italy.
- CRC Laboratorio di Materiali e Polimeri (LaMPo), Department of Chemistry, Università degli Studi di Milano, Via Golgi 19, Milano 20133, Italy.
- ESRF-The European Synchrotron, 71 Avenue des Martyrs, Grenoble 38000, France.
| | - Dimitrios Fessas
- DeFENS-Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, Via Celoria 2, Milano 20133, Italy.
- CRC Laboratorio di Materiali e Polimeri (LaMPo), Department of Chemistry, Università degli Studi di Milano, Via Golgi 19, Milano 20133, Italy.
| | - Luciano Piergiovanni
- DeFENS-Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, Via Celoria 2, Milano 20133, Italy.
- CRC Laboratorio di Materiali e Polimeri (LaMPo), Department of Chemistry, Università degli Studi di Milano, Via Golgi 19, Milano 20133, Italy.
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Terenzi C, Prakobna K, Berglund LA, Furó I. Nanostructural Effects on Polymer and Water Dynamics in Cellulose Biocomposites: 2H and 13C NMR Relaxometry. Biomacromolecules 2015; 16:1506-15. [DOI: 10.1021/acs.biomac.5b00330] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Camilla Terenzi
- Division of Applied
Physical Chemistry, ‡Wallenberg Wood Science Centre, and §Department of
Fibre and Polymer Technology, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Kasinee Prakobna
- Division of Applied
Physical Chemistry, ‡Wallenberg Wood Science Centre, and §Department of
Fibre and Polymer Technology, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Lars A. Berglund
- Division of Applied
Physical Chemistry, ‡Wallenberg Wood Science Centre, and §Department of
Fibre and Polymer Technology, KTH Royal Institute of Technology, Stockholm, Sweden
| | - István Furó
- Division of Applied
Physical Chemistry, ‡Wallenberg Wood Science Centre, and §Department of
Fibre and Polymer Technology, KTH Royal Institute of Technology, Stockholm, Sweden
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Blicharska B, Peemoeller H, Witek M. Hydration water dynamics in biopolymers from NMR relaxation in the rotating frame. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2010; 207:287-293. [PMID: 20961779 DOI: 10.1016/j.jmr.2010.09.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Revised: 09/13/2010] [Accepted: 09/18/2010] [Indexed: 05/30/2023]
Abstract
Assuming dipole-dipole interaction as the dominant relaxation mechanism of protons of water molecules adsorbed onto macromolecule (biopolymer) surfaces we have been able to model the dependences of relaxation rates on temperature and frequency. For adsorbed water molecules the correlation times are of the order of 10(-5)s, for which the dispersion region of spin-lattice relaxation rates in the rotating frame R(1)(ρ)=1/T(1)(ρ) appears over a range of easily accessible B(1) values. Measurements of T(1)(ρ) at constant temperature and different B(1) values then give the "dispersion profiles" for biopolymers. Fitting a theoretical relaxation model to these profiles allows for the estimation of correlation times. This way of obtaining the correlation time is easier and faster than approaches involving measurements of the temperature dependence of R(1)=1/T(1). The T(1)(ρ) dispersion approach, as a tool for molecular dynamics study, has been demonstrated for several hydrated biopolymer systems including crystalline cellulose, starch of different origins (potato, corn, oat, wheat), paper (modern, old) and lyophilized proteins (albumin, lysozyme).
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AGO M, SATO K, ENDO T, OKAJIMA K. Effects of Hydrophilic and Hydrophobic Solvents on Solid Structure and Molecular Mobility of Cellulose. KOBUNSHI RONBUNSHU 2008. [DOI: 10.1295/koron.65.483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Olsson AM, Salmén L. The association of water to cellulose and hemicellulose in paper examined by FTIR spectroscopy. Carbohydr Res 2004; 339:813-8. [PMID: 14980824 DOI: 10.1016/j.carres.2004.01.005] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2003] [Accepted: 01/13/2004] [Indexed: 11/23/2022]
Abstract
The nature of water sorption to different materials has always been a complex matter to address, partly due to the different possibilities of hydrogen-bond formation. For cellulosic materials this is extremely important for its product performance. In order to gain a deeper understanding of the moisture adsorption mechanisms of cellulose and hemicelluloses, the molecular interaction between moisture and paper and between moisture and some wood polymers was studied using FTIR spectroscopy under stable humid conditions. It was found that all the moisture-sorbing sites adsorbed moisture to the same relative degree, and that the rate of adsorption was the same for all these sites. It was also noticed that the moisture is adsorbed in the form of clusters. A direct relationship was found between the moisture weight gain and the increase in the absorbance peaks for humidities up to 50% relative humidity after which the moisture gain increased faster, a fact that still remains to be explained.
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Affiliation(s)
- Anne-Mari Olsson
- STFI, Swedish Pulp and Paper Research Institute, Box 5604, SE-114 86 Stockholm, Sweden.
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Miller AF, Donald AM. Imaging of anisotropic cellulose suspensions using environmental scanning electron microscopy. Biomacromolecules 2003; 4:510-7. [PMID: 12741764 DOI: 10.1021/bm0200837] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The effect of concentration on anisotropic phase behavior of acid-hydrolyzed cellulose suspensions has been examined using conventional polarizing microscopy and the novel technique of environmental scanning electron microscopy (ESEM). Microcrystalline cellulose dispersed in water formed biphasic suspensions in a narrow concentration range, 4-12 wt % for a suspension pH of 4, where the upper and lower phases were isotropic and anisotropic (chiral nematic), respectively. It is known from previous work that within the biphasic regime total suspension concentration affects only the volume fractions of the two phases, not phase concentration or interfacial packing. As the total suspension concentration surpassed the upper critical limit (c), however, a single anisotropic phase of increasing concentration was observed. It was evident from polarizing microscopy that the chiral nematic pitch of the anisotropic phase decreased with increasing concentration, which has been attributed to a reduction in the electrostatic double layer thickness of the individual rods, thus increasing intermolecular interactions. Chiral nematic textures were also visible using ESEM. This technique has the advantage of studying individual rod orientation within the liquid crystalline phase as it permits the high resolution of electron microscopy to be applied to hydrated samples in their natural state. To our knowledge this is the first time such lyotropic systems have been observed using electron microscopy.
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Affiliation(s)
- Aline F Miller
- Polymers and Colloids Group, Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE, UK
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Axelson DE, Wooten JB. Bulk analysis of tobacco and cigarettes by magnetic resonance imaging. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2000; 48:2199-207. [PMID: 10888522 DOI: 10.1021/jf991075t] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Proton magnetic resonance imaging of tobacco blends in cigarette rods was investigated to assess the feasibility of various imaging protocols to characterize and quantify the structure and composition of multiphase plant materials in situ. The protocols used to characterize the rigid molecular components (plant cell wall) included single-point imaging (SPI) and a variant experiment, single-point ramped imaging with T(1) enhancement (SPRITE). Both 1D profiles, radially averaged along the length of a cigarette, and 2D maps of proton spin density and relaxation (T(2)) were acquired. Mobile components (tobacco waxes and water) were examined via conventional spin-echo imaging techniques, with 1D, 2D, and 3D data being acquired. Spin-spin relaxation times (T(2)), apparent spin-spin relaxation (T(2)), and spin-lattice (T(1)) relaxation times were measured for selected samples.
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Hatakeyama T, Nakamura K, Yoshida H, Hatakeyama H. Mesomorphic properties of highly concentrated aqueous solutions of polyelectrolytes from saccharides. Food Hydrocoll 1989. [DOI: 10.1016/s0268-005x(89)80041-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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