1
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Anukunwithaya P, Liu N, Liu S, Thanayupong E, Zhou L, Pimpha N, Min J, Chinsirikul W, Thitsartarn W, Koh JJ, He C. Low vaporization enthalpy of modified chitosan hydrogel for high performance solar evaporator. Carbohydr Polym 2024; 340:122304. [PMID: 38858008 DOI: 10.1016/j.carbpol.2024.122304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 05/16/2024] [Accepted: 05/20/2024] [Indexed: 06/12/2024]
Abstract
The high vaporization enthalpy of water attributed to the strong hydrogen bonds between water molecules is limiting the performance of solar evaporators. This work demonstrates a deliberate attempt to significantly reduce the vaporization enthalpy of water through the introduction of weak water-amine hydrogen bond interactions in hydrogel evaporators. In this article, bio-based chitosan-agarose/multiwalled carbon nanotube hydrogel film evaporators (CAMFEs) exhibit larger vaporization enthalpy reduction with the presence of primary amine groups in chitosan. An interplay between vaporization enthalpy reduction and water diffusivity leads to an optimal ratio of chitosan to agarose = 7:1 (CAMFE7) showing an impressive evaporation rate of 4.13 kg m-2 h-1 under 1 sun irradiation. CAMFE7 also exhibits excellent salt resistance, with a stable water evaporation rate, using brine water of up to 10 % salinity under continuous 1 sun irradiation. The high mechanical robustness together with its scalability makes CAMFE7 a highly promising material for practical drinking water production.
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Affiliation(s)
- Patsaya Anukunwithaya
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575, Republic of Singapore; National Nanotechnology Center, National Science and Technology Development Agency, Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani, 12120, Thailand
| | - Nanxue Liu
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575, Republic of Singapore
| | - Siqi Liu
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575, Republic of Singapore
| | - Eknarin Thanayupong
- National Nanotechnology Center, National Science and Technology Development Agency, Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani, 12120, Thailand
| | - Lili Zhou
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575, Republic of Singapore
| | - Nuttaporn Pimpha
- National Nanotechnology Center, National Science and Technology Development Agency, Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani, 12120, Thailand
| | - Jiakang Min
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Republic of Singapore
| | - Wannee Chinsirikul
- National Nanotechnology Center, National Science and Technology Development Agency, Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani, 12120, Thailand
| | - Warintorn Thitsartarn
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
| | - J Justin Koh
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore.
| | - Chaobin He
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575, Republic of Singapore; Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore.
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2
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Rodrigues NT, Alves Aarão Reis FD. Adsorption of Diffusing Tracers, Apparent Tortuosity, and Application to Mesoporous Silica. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:11371-11380. [PMID: 38758366 PMCID: PMC11155253 DOI: 10.1021/acs.langmuir.3c03855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 05/08/2024] [Accepted: 05/09/2024] [Indexed: 05/18/2024]
Abstract
The apparent tortuosity due to adsorption of diffusing tracers in a porous material is determined by a scaling approach and is used to analyze recent data on LiCl and alkane diffusion in mesoporous silica. The slope of the adsorption isotherm at small loadings is written as β = qA/qG, where qA is the adsorption-desorption ratio and qG = ϵ/(as) - 1 is a geometrical factor depending on the range a of the tracer-wall interaction, the porosity ϵ, and the specific surface area s. The adsorption leads to a decrease of effective diffusion coefficient, which is quantified by multiplying the geometrical tortuosity factor τgeom by an apparent tortuosity factor τapp. In wide pores or when the adsorption barrier is high, τapp = β + 1, as obtained in previous works, but in narrow pores there is an additional contribution from frequent adsorption-desorption transitions. These results are obtained in media with parallel pores of constant cross sections, where the ratio between the effective pore width ϵ/s and the actual width is ≈0.25. Applications to mesoporous silica samples are justified by the small deviations from this ideal ratio. In the analysis of alkane self-diffusion data, the fractions of adsorbed molecules predicted in a recent theoretical work are used to estimate τgeom of the silica samples, which is ≫1 only in the sample with the narrowest pores (nominal 3 nm). The application of the model to Li+ ion diffusion leads to similar values of τgeom and to a difference of energy barriers of desorption and adsorption for those ions of ∼0.06 eV. Comparatively, alkane self-diffusion provides the correct order of magnitude of τgeom, with adsorption playing a less important role, whereas adsorption effects on Li+ diffusion are much more important.
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Affiliation(s)
- Nathann Teixeira Rodrigues
- Instituto de Física, Universidade Federal Fluminense, Avenida Litorânea s/n, 24210-340 Niterói, RJ, Brazil
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3
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Chen W, Biehl P, Huang C, Zhang K. Viscoelastic Response in Hydrous Polymers: The Role of Hydrogen Bonds and Microstructure. NANO LETTERS 2024; 24:3811-3818. [PMID: 38470141 PMCID: PMC10979449 DOI: 10.1021/acs.nanolett.4c00556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 03/05/2024] [Accepted: 03/06/2024] [Indexed: 03/13/2024]
Abstract
Water responsive polymers represent a remarkable group of soft materials, acting as a laboratory for diverse water responsive physical phenomena and cutting-edge biology-electronics interfaces. We report on peculiarly distinctive viscoelastic behaviors of the biobased water responsive polymer cellulose 10-undecenoyl ester, while biobased regenerated cellulose displays stronger hydroplastic behaviors. We discovered a novel hydrous deformation mechanism involving the stretching of hydrogen bonds mediated by hydroxyl groups and water molecules, serving as a crucial factor in accommodating deformations. In parallel, the microstructure of cellulose 10-undecenoyl ester with unique coexisting nanoparticles and a continuous phase of entangled chains is mechanically resilient in the anhydrous state but enhances structural stiffness in the hydrous state. This variation arises from a different hydration level within the hydrous microstructure. Such a fundamental discovery offers valuable insights into the connection between the microscopic physical properties that can be influenced by water and the corresponding viscoelastic responses, extending its applicability to a wide range of hygroscopic materials.
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Affiliation(s)
- Wenbo Chen
- Sustainable
Materials and Chemistry, Department of Wood Technology and Wood-based
Composites, University of Göttingen, Büsgenweg 4, Göttingen 37077, Germany
| | - Philip Biehl
- Sustainable
Materials and Chemistry, Department of Wood Technology and Wood-based
Composites, University of Göttingen, Büsgenweg 4, Göttingen 37077, Germany
| | - Caoxing Huang
- Sustainable
Materials and Chemistry, Department of Wood Technology and Wood-based
Composites, University of Göttingen, Büsgenweg 4, Göttingen 37077, Germany
- Co-Innovation
Center of Efficient Processing and Utilization of Forest Resources,
College of Chemical Engineering, Nanjing
Forestry University, Nanjing, Jiangsu 210037, China
| | - Kai Zhang
- Sustainable
Materials and Chemistry, Department of Wood Technology and Wood-based
Composites, University of Göttingen, Büsgenweg 4, Göttingen 37077, Germany
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4
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Zhang C, Shomali A, Coasne B, Derome D, Carmeliet J. Sorption-Deformation-Percolation Model for Diffusion in Nanoporous Media. ACS NANO 2023; 17:4507-4514. [PMID: 36846983 PMCID: PMC10018761 DOI: 10.1021/acsnano.2c10384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Abstract
Diffusion of molecules in porous media is a critical process that is fundamental to numerous chemical, physical, and biological applications. The prevailing theoretical frameworks are challenged when explaining the complex dynamics resulting from the highly tortuous host structure and strong guest-host interactions, especially when the pore size approximates the size of diffusing molecule. This study, using molecular dynamics, formulates a semiempirical model based on theoretical considerations and factorization that offer an alternative view of diffusion and its link with the structure and behavior (sorption and deformation) of material. By analyzing the intermittent dynamics of water, microscopic self-diffusion coefficients are predicted. The apparent tortuosity, defined as the ratio of the bulk to the confined self-diffusion coefficients, is found to depend quantitatively on a limited set of material parameters: heat of adsorption, elastic modulus, and percolation probability, all of which are experimentally accessible. The proposed sorption-deformation-percolation model provides guidance on the understanding and fine-tuning of diffusion.
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Affiliation(s)
- Chi Zhang
- Chair
of Building Physics, Department of Mechanical and Process Engineering, ETH Zurich, Rämistrasse 101, 8092 Zürich, Switzerland
| | - Ali Shomali
- Chair
of Building Physics, Department of Mechanical and Process Engineering, ETH Zurich, Rämistrasse 101, 8092 Zürich, Switzerland
| | - Benoit Coasne
- Université
Grenoble Alpes, CNRS, LIPhy, 38000 Grenoble, France
| | - Dominique Derome
- Department
of Civil and Building Engineering, Université
de Sherbrooke, Sherbrooke J1K 2R1, Québec, Canada
| | - Jan Carmeliet
- Chair
of Building Physics, Department of Mechanical and Process Engineering, ETH Zurich, Rämistrasse 101, 8092 Zürich, Switzerland
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5
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Salem KS, Naithani V, Jameel H, Lucia L, Pal L. A systematic examination of the dynamics of water-cellulose interactions on capillary force-induced fiber collapse. Carbohydr Polym 2022; 295:119856. [DOI: 10.1016/j.carbpol.2022.119856] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 07/06/2022] [Accepted: 07/07/2022] [Indexed: 11/28/2022]
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6
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Paajanen A, Zitting A, Rautkari L, Ketoja JA, Penttilä PA. Nanoscale Mechanism of Moisture-Induced Swelling in Wood Microfibril Bundles. NANO LETTERS 2022; 22:5143-5150. [PMID: 35767745 PMCID: PMC9284609 DOI: 10.1021/acs.nanolett.2c00822] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Understanding nanoscale moisture interactions is fundamental to most applications of wood, including cellulosic nanomaterials with tailored properties. By combining X-ray scattering experiments with molecular simulations and taking advantage of computed scattering, we studied the moisture-induced changes in cellulose microfibril bundles of softwood secondary cell walls. Our models reproduced the most important experimentally observed changes in diffraction peak locations and widths and gave new insights into their interpretation. We found that changes in the packing of microfibrils dominate at moisture contents above 10-15%, whereas deformations in cellulose crystallites take place closer to the dry state. Fibrillar aggregation is a significant source of drying-related changes in the interior of the microfibrils. Our results corroborate the fundamental role of nanoscale phenomena in the swelling behavior and properties of wood-based materials and promote their utilization in nanomaterials development. Simulation-assisted scattering analysis proved an efficient tool for advancing the nanoscale characterization of cellulosic materials.
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Affiliation(s)
- Antti Paajanen
- VTT
Technical Research Centre of Finland Ltd, P.O. Box 1000, FI-02044 VTT, Espoo, Finland
| | - Aleksi Zitting
- Department
of Bioproducts and Biosystems, Aalto University, P.O. Box 16300, FI-00076 Aalto, Espoo, Finland
| | - Lauri Rautkari
- Department
of Bioproducts and Biosystems, Aalto University, P.O. Box 16300, FI-00076 Aalto, Espoo, Finland
| | - Jukka A. Ketoja
- VTT
Technical Research Centre of Finland Ltd, P.O. Box 1000, FI-02044 VTT, Espoo, Finland
| | - Paavo A. Penttilä
- Department
of Bioproducts and Biosystems, Aalto University, P.O. Box 16300, FI-00076 Aalto, Espoo, Finland
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7
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Guccini V, Yu S, Meng Z, Kontturi E, Demmel F, Salazar-Alvarez G. The Impact of Surface Charges of Carboxylated Cellulose Nanofibrils on the Water Motions in Hydrated Films. Biomacromolecules 2022; 23:3104-3115. [PMID: 35786867 PMCID: PMC9364319 DOI: 10.1021/acs.biomac.1c01517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cellulose nanofibrils (CNFs) with carboxylated surface ligands are a class of materials with tunable surface functionality, good mechanical properties, and bio-/environmental friendliness. They have been used in many applications as scaffold, reinforcing, or functional materials, where the interaction between adsorbed moisture and the CNF could lead to different properties and structures and become critical to the performance of the materials. In this work, we exploited multiple experimental methods to study the water movement in hydrated films made of carboxylated CNFs prepared by TEMPO oxidation with two different surface charges of 600 and 1550 μmol·g-1. A combination of quartz crystal microbalance with dissipation (QCM-D) and small-angle X-ray scattering (SAXS) shows that both the surface charge of a single fibril and the films' network structure contribute to the moisture uptake. The films with 1550 μmol·g-1 surface charges take up twice the amount of moisture per unit mass, leading to the formation of nanostructures with an average radius of gyration of 2.1 nm. Via the nondestructive quasi-elastic neutron scattering (QENS), a faster motion is explained as a localized movement of water molecules inside confined spheres, and a slow diffusive motion is found with the diffusion coefficient close to bulk water at room temperature via a random jump diffusion model and regardless of the surface charge in films made from CNFs.
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Affiliation(s)
- Valentina Guccini
- Department of Materials and Environmental Chemistry (MMK), Stockholm University, Stockholm SE-10691, Sweden.,Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, P.O. Box 16300, Aalto 00076, Finland
| | - Shun Yu
- Department of Materials and Environmental Chemistry (MMK), Stockholm University, Stockholm SE-10691, Sweden.,Smart Materials, Division of Bioeconomy and Health, RISE Research Institute of Sweden, Drottning Kristinas väg 61, Stockholm 114 86, Sweden
| | - Zhoujun Meng
- Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, P.O. Box 16300, Aalto 00076, Finland
| | - Eero Kontturi
- Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, P.O. Box 16300, Aalto 00076, Finland
| | - Franz Demmel
- ISIS Facility, Rutherford Appleton Laboratory, Didcot OX11 0QZ, UK
| | - Germán Salazar-Alvarez
- Department of Materials and Environmental Chemistry (MMK), Stockholm University, Stockholm SE-10691, Sweden.,Department of Materials Science and Engineering, Ångström Laboratory, Uppsala University, Box 35, Uppsala SE-751 03, Sweden.,Center for Neutron Scattering, Uppsala University, Box 35, Uppsala SE-751 03, Sweden
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8
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Ramamohan P, Furó I, Wohlert J. Timescales for convergence in all-atom molecular dynamics simulations of hydrated amorphous xylan. Carbohydr Polym 2022; 286:119263. [DOI: 10.1016/j.carbpol.2022.119263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 02/04/2022] [Accepted: 02/15/2022] [Indexed: 11/02/2022]
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9
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Bama JA, Dudognon E, Affouard F. Impact of Low Concentration of Strongly Hydrogen-Bonded Water Molecules on the Dynamics of Amorphous Terfenadine: Insights from Molecular Dynamics Simulations and Dielectric Relaxation Spectroscopy. J Phys Chem B 2021; 125:11292-11307. [PMID: 34590855 DOI: 10.1021/acs.jpcb.1c06087] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The impact of low water concentration of strongly hydrogen-bonded water molecules on the dynamical properties of amorphous terfenadine (TFD) is investigated through complementary molecular dynamics (MD) simulations and dielectric relaxation spectroscopy (DRS) experiments. In this article, we especially highlight the important role played by some residual water molecules in the concentration of 1-2% (w/w) trapped in the TFD glassy matrix, which are particularly difficult to remove experimentally without a specific heating/drying process. From MD computations and analyses of the hydrogen bonding (HB) interactions, different categories of water molecules are revealed and particularly the presence of strongly HB water molecules. These latter localize themselves in small pockets in empty spaces existing in between the TFD molecules due to the poor packing of the glassy state and preferentially interact with the polar groups close to the flexible central part of the TFD molecules. We present a simple model which rationalizes at the molecular scale the effect of these strongly HB water molecules on dynamics and how they give rise to a supplementary relaxation process (namely process S) which is detected for the first time in the glassy state of TFD annealed at room temperature while this process is completely absent in a non-annealed glass. It also explains how this supplementary relaxation is coupled with the intramolecular motion (namely process γ) of the very flexible central part of the TFD molecule. The present findings help to understand more generally the microscopic origin of the secondary relaxations often detected by DRS in the glassy states of molecular compounds for which the exact nature is still debated.
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Affiliation(s)
- Jeanne-Annick Bama
- University Lille, CNRS, INRAE, Centrale Lille, UMR 8207-UMET-Unité Matériaux et Transformations, Lille F-59000, France
| | - Emeline Dudognon
- University Lille, CNRS, INRAE, Centrale Lille, UMR 8207-UMET-Unité Matériaux et Transformations, Lille F-59000, France
| | - Frédéric Affouard
- University Lille, CNRS, INRAE, Centrale Lille, UMR 8207-UMET-Unité Matériaux et Transformations, Lille F-59000, France
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10
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Bridging scales in disordered porous media by mapping molecular dynamics onto intermittent Brownian motion. Nat Commun 2021; 12:1043. [PMID: 33589629 PMCID: PMC7884405 DOI: 10.1038/s41467-021-21252-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 01/15/2021] [Indexed: 11/08/2022] Open
Abstract
Owing to their complex morphology and surface, disordered nanoporous media possess a rich diffusion landscape leading to specific transport phenomena. The unique diffusion mechanisms in such solids stem from restricted pore relocation and ill-defined surface boundaries. While diffusion fundamentals in simple geometries are well-established, fluids in complex materials challenge existing frameworks. Here, we invoke the intermittent surface/pore diffusion formalism to map molecular dynamics onto random walk in disordered media. Our hierarchical strategy allows bridging microscopic/mesoscopic dynamics with parameters obtained from simple laws. The residence and relocation times - tA, tB - are shown to derive from pore size d and temperature-rescaled surface interaction ε/kBT. tA obeys a transition state theory with a barrier ~ε/kBT and a prefactor ~10-12 s corrected for pore diameter d. tB scales with d which is rationalized through a cutoff in the relocation first passage distribution. This approach provides a formalism to predict any fluid diffusion in complex media using parameters available to simple experiments.
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11
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He J, Ju Y, Lammers L, Kulasinski K, Zheng L. Tortuosity of kerogen pore structure to gas diffusion at molecular- and nano-scales: A molecular dynamics simulation. Chem Eng Sci 2020. [DOI: 10.1016/j.ces.2019.115460] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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12
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Bülbül E, Hegemann D, Geue T, Heuberger M. How the dynamics of subsurface hydration regulates protein-surface interactions. Colloids Surf B Biointerfaces 2020; 190:110908. [PMID: 32163842 DOI: 10.1016/j.colsurfb.2020.110908] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 02/13/2020] [Accepted: 02/25/2020] [Indexed: 10/24/2022]
Abstract
The role of water structure near surfaces has been scrutinized extensively because it is accepted to control protein-surface interactions, however, often avoiding effects of hydration dynamics. Relating to this, we have recently discussed how the amount and state of water, accumulated within various hydrophobic-to-hydrophilic subsurface gradients of plasma polymer films, influence the magnitude of adsorbed bovine serum albumin, spurring the hypothesis of the presence of a subsurface dipolar field. This study now analyzes the kinetics of hydration by systematically introducing modified gradient architectures and relating different hydration times to the adsorption of a dipolar probing protein. We find that dry-stored subsurface gradients, owing nominally identical surface characteristics, exhibits comparable surface potential and protein adsorption values, while they behave in a different manner at transient hydration times of few hours, before reaching near-equilibrium state of the hydration. A characteristic hydration time is found where protein adsorption on gradient films is minimal, unveiling the transient nature of the effect. In general, protein adsorption is sensitive to the time allowed for hydration of the adsorbent surface, supporting our initial hypothesis inasmuch as the quantity as well as quality of water inside the subsurface matrix is crucial for controlling protein-surface interactions.
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Affiliation(s)
- Ezgi Bülbül
- Laboratory for Advanced Fibers, Empa, Swiss Federal Laboratories for Materials Science and Technology, 9014, St. Gallen, Switzerland; Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, 8093, Zurich, Switzerland.
| | - Dirk Hegemann
- Laboratory for Advanced Fibers, Empa, Swiss Federal Laboratories for Materials Science and Technology, 9014, St. Gallen, Switzerland.
| | - Thomas Geue
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute (PSI), 5232, Villigen, Switzerland.
| | - Manfred Heuberger
- Laboratory for Advanced Fibers, Empa, Swiss Federal Laboratories for Materials Science and Technology, 9014, St. Gallen, Switzerland; Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, 8093, Zurich, Switzerland.
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13
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Tensile behaviour of dislocated/crystalline cellulose fibrils at the nano scale. Carbohydr Polym 2020; 235:115946. [PMID: 32122482 DOI: 10.1016/j.carbpol.2020.115946] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 01/31/2020] [Accepted: 02/02/2020] [Indexed: 11/23/2022]
Abstract
Atomistic modelling of cellulose has widely been investigated for years using molecular dynamics simulations. In this paper, we model Iβ crystalline cellulose as well as develop a model including dislocations in between the crystal regions. The model including dislocations shows a tensile modulus of 109 GPa, 25% lower than that of the fully crystalline model (146 GPa). The change in dihedral angle preferences is analysed, and its effect on hydrogen bonding pattern is assessed. How presence of hydrogen bonds contributes to elastic properties of cellulose nano-fibrils is shown. Effect of water on the elastic modulus of fibrils is also investigated. Moreover, an illustration is given of how the tensile behaviour of fibrils is controlled by a synergy between the geometry changes occurring at the glycosidic linkage, reflected by specific torsional and glycosidic angles. These findings can be useful in further modelling of cellulosic fibrils at the atomistic and coarse-grained scales.
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14
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Gravelle S, Dumais J. A multi-scale model for fluid transport through a bio-inspired passive valve. J Chem Phys 2020; 152:014502. [PMID: 31914744 DOI: 10.1063/1.5126481] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Tillandsia landbeckii is a rootless plant thriving in the hyper-arid Atacama Desert of Chile. These plants use unique cellulose-based microscopic structures called trichomes to collect fresh water from coastal fog. The trichomes rely on a passive mechanism to maintain an asymmetrical transport of water: they allow for the fast absorption of liquid water deposited by sporadic fog events while preventing evaporation during extended drought periods. Inspired by the trichome's design, we study fluid transport through a micrometric valve. Combining Grand Canonical Monte Carlo with Non-Equilibrium Molecular Dynamics simulations, we first analyze the adsorption and transport of a fluid through a single nanopore at different chemical potentials. We then scale up the atomic results using a lattice approach, and simulate the transport at the micrometric scale. Results obtained for a model Lennard-Jones fluid and TIP4P/2005 water were compared, allowing us to identify the key physical parameters for achieving a passive hydraulic valve. Our results show that the difference in transport properties of water vapor and liquid water within the cellulose layer is the basis for the ability of the Tillandsia trichome to function as a water valve. Finally, we predict a critical pore dimension above which the cellulose layer can form an efficient valve.
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Affiliation(s)
- Simon Gravelle
- Facultad de Ingenieria y Ciencias, Universidad Adolfo Ibáñez, Viña del Mar, Chile
| | - Jacques Dumais
- Facultad de Ingenieria y Ciencias, Universidad Adolfo Ibáñez, Viña del Mar, Chile
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15
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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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16
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Abstract
Wood, a complex hierarchical material, continues to be widely used as a resource to meet humankind’s material needs, in addition to providing inspiration for the development of new biomimetic materials. However, for wood to meet its full potential, researchers must overcome the challenge of understanding its fundamental moisture-related properties across its many levels of hierarchy spanning from the molecular scale up to the bulk wood level. In this perspective, a review of recent research on wood moisture-induced swelling and shrinking is presented from the molecular level to the cellular scale. Numerous aspects of swelling and shrinking in wood remain poorly understood, sub-cellular phenomena in particular, because it can be difficult to study them experimentally. Here, we discuss recent research endeavors at each of the relevant length scales, including the molecular, cellulose elementary fibril, secondary cell wall layer nanostructure, cell wall, cell, and cellular levels. At each length scale, we provide a discussion on the current knowledge and suggestions for future research. The potential impacts of moisture-induced swelling pressures on experimental observations of swelling and shrinking in wood at different length scales are also recognized and discussed.
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Wood–Moisture Relationships Studied with Molecular Simulations: Methodological Guidelines. FORESTS 2019. [DOI: 10.3390/f10080628] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This paper aims at providing a methodological framework for investigating wood polymers using atomistic modeling, namely, molecular dynamics (MD) and grand canonical Monte Carlo (GCMC) simulations. Atomistic simulations are used to mimic water adsorption and desorption in amorphous polymers, make observations on swelling, mechanical softening, and on hysteresis. This hygromechanical behavior, as observed in particular from the breaking and reforming of hydrogen bonds, is related to the behavior of more complex polymeric composites. Wood is a hierarchical material, where the origin of wood-moisture relationships lies at the nanoporous material scale. As water molecules are adsorbed into the hydrophilic matrix in the cell walls, the induced fluid–solid interaction forces result in swelling of these cell walls. The interaction of the composite polymeric material, that is the layer S2 of the wood cell wall, with water is known to rearrange its internal material structure, which makes it moisture sensitive, influencing its physical properties. In-depth studies of the coupled effects of water sorption on hygric and mechanical properties of different polymeric components can be performed with atomistic modeling. The paper covers the main components of knowledge and good practice for such simulations.
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On the Experimental Assessment of the Molecular-Scale Interactions between Wood and Water. FORESTS 2019. [DOI: 10.3390/f10080616] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Although molecular-scale wood-water interactions needed for moisture-durability can lead to the accelerated development of moisture-durable products, these interactions are often experimentally elusive. In this perspective, the topic’s state of the art understanding will be discussed, excluding computational work. Recent research efforts based on infrared spectroscopy methods have provided new insights in terms of the accessibility of the wood polymers and moisture-induced polymer dynamics. Likewise, neutron scattering and nuclear magnetic relaxometry experiments have shown that bound water can be found within more than one local environment inside the cell wall. However, a majority of the experiments have focused on studying extracted or derived polymers instead of unmodified wood. Thus, in this paper some of the questions that still need to be addressed experimentally will also be highlighted.
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Kulasinski K. Free Energy Landscape of Cellulose as a Driving Factor in the Mobility of Adsorbed Water. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:5362-5370. [PMID: 28510442 DOI: 10.1021/acs.langmuir.7b00914] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The diffusion coefficient of water adsorbed in hydrophilic porous materials, such as noncrystalline cellulose, depends on water activity. Faster diffusion at higher water concentrations is observed in experimental and modeling studies. In this paper, two asymptotic water concentrations, near-vacuum and fully saturated, are investigated at the surface of crystalline cellulose with molecular dynamics simulations. An increasing water concentration leads to significant changes in the free energy landscape due to perturbation of local electrostatic potential. Smoothening of strong energy minima, corresponding to sorption sites, and formation of layered structure facilitates water transport in the vicinity of cellulose. The determined transition probabilities and hydrogen bond stability reflect the changes in the energy landscape. As a result of a concentration increase, the emerging basins of attraction and spreading out of those existing in the diluted state lead to an increase in water entropy. Thermal fluctuations of cellulose are demonstrated to rearrange the landscape in the diluted limit, increase adsorbed water entropy, and decrease the water-cellulose H-bond lifetime.
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Affiliation(s)
- Karol Kulasinski
- Department of Geochemistry, Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory , Berkeley, California, 94720, United States
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Tokunaga TK, Finsterle S, Kim Y, Wan J, Lanzirotti A, Newville M. Ion Diffusion Within Water Films in Unsaturated Porous Media. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:4338-4346. [PMID: 28350957 DOI: 10.1021/acs.est.6b05891] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Diffusion is important in controlling local solute transport and reactions in unsaturated soils and geologic formations. Although it is commonly assumed that thinning of water films controls solute diffusion at low water contents, transport under these conditions is not well understood. We conducted experiments in quartz sands at low volumetric water contents (θ) to quantify ion diffusion within adsorbed films. At the lowest water contents, we employed fixed relative humidities to control water films at nm thicknesses. Diffusion profiles for Rb+ and Br- in unsaturated sand packs were measured with a synchrotron X-ray microprobe, and inverse modeling was used to determine effective diffusion coefficients, De, as low as ∼9 × 10-15 m2 s-1 at θ = 1.0 × 10-4 m3 m-3, where the film thickness = 0.9 nm. Given that the diffusion coefficients (Do) of Rb+ and Br- in bulk water (30 °C) are both ∼2.4 × 10-9 m2 s-1, we found the impedance factor f = De/(θDo) is equal to 0.03 ± 0.02 at this very low saturation, in agreement with the predicted influence of interface tortuosity (τa) for diffusion along grain surfaces. Thus, reduced cross-sectional area (θ) and tortuosity largely accounted for the more than 5 orders of magnitude decrease in De relative to Do as desaturation progressed down to nanoscale films.
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Affiliation(s)
- Tetsu K Tokunaga
- Energy Geosciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Stefan Finsterle
- Energy Geosciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Yongman Kim
- Energy Geosciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Jiamin Wan
- Energy Geosciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Antonio Lanzirotti
- Center for Advanced Radiation Sources, The University of Chicago , Chicago, Illinois 60637, United States
| | - Matthew Newville
- Center for Advanced Radiation Sources, The University of Chicago , Chicago, Illinois 60637, United States
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Mathesan S, Rath A, Ghosh P. Insights on Water Dynamics in the Hygromorphic Phenomenon of Biopolymer Films. J Phys Chem B 2017; 121:4273-4282. [DOI: 10.1021/acs.jpcb.7b00980] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Santhosh Mathesan
- Nanomechanics and Nanomaterials Laboratory, Department of Applied Mechanics & Soft Matter Center, Indian Institute of Technology Madras, Chennai 600 036, India
| | - Amrita Rath
- Nanomechanics and Nanomaterials Laboratory, Department of Applied Mechanics & Soft Matter Center, Indian Institute of Technology Madras, Chennai 600 036, India
| | - Pijush Ghosh
- Nanomechanics and Nanomaterials Laboratory, Department of Applied Mechanics & Soft Matter Center, Indian Institute of Technology Madras, Chennai 600 036, India
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