Browse
Submit Data
Databases
API
Help

Dataset Information

16 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Mesoporosity of Delignified Wood Investigated by Water Vapor Sorption.

ABSTRACT: Wood represents a highly suitable biobased scaffold for the development of mechanically robust and functional materials. Its functionalizability can be enhanced by means of delignification, resulting in an increase in porosity due to partial or complete removal of lignin and hemicellulose constituents. In this work, the impact of partial and complete delignification on the mesoporous structure is investigated via water vapor sorption isotherms and deuterium exchange. Pore size distributions of wood samples with five different delignification levels were compared to native wood. The derived pore size distributions at the water swollen state reveal an increase in porosity with decreasing lignin content. However, after complete lignin removal, drying causes a nonreversible collapse of the cell wall, which results in reduced porosity.

SUBMITTER: Gronquist P

PROVIDER: S-EPMC6682004 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Mesoporosity of Delignified Wood Investigated by Water Vapor Sorption.

Grönquist Philippe P Frey Marion M Keplinger Tobias T Burgert Ingo I

ACS omega 20190722 7

Wood represents a highly suitable biobased scaffold for the development of mechanically robust and functional materials. Its functionalizability can be enhanced by means of delignification, resulting in an increase in porosity due to partial or complete removal of lignin and hemicellulose constituents. In this work, the impact of partial and complete delignification on the mesoporous structure is investigated via water vapor sorption isotherms and deuterium exchange. Pore size distributions of w ...[more]

PMID: 31460361

Similar Datasets

Water Vapor Sorption and Diffusivity in Bio-Based Poly(Ethylene Vanillate)-PEV.

Project description:The dynamic and equilibrium water vapor sorption properties of amorphous and highly crystalline poly(ethylene vanillate) (PEV) films were determined via gravimetric analysis, at 20 °C, over a wide range of relative humidity (0-95% RH). At low RH%, the dynamic of the sorption process obeys Fick's law while at higher relative humidity it is characterized by a drift ascribable to non-Fickian relaxations. The non-Fickian relaxations, which are responsible for the incorporation of additional water, are correlated with the upturn of the sorption isotherms and simultaneously the hysteresis recorded between sorption and desorption cycles. The sorption isotherms of amorphous and highly crystalline PEV are arranged in the same concentration range of that of PET proving the similarity of the two polyesters. Water diffusion coefficients, whose determination from individual kinetic sorption/desorption curves required treatment with the Barens-Hopfenberg model, were demonstrated to be ≈ 10× higher for amorphous PEV compared to amorphous PET. Such a difference originates from the enhanced segmental flexibility of PEV chains.

| S-EPMC7916482 | biostudies-literature

Sorption Study of Water Vapor and a Dye on Chitosan-Based Framework Materials.

Project description:Two types of chitosan framework materials were functionalized with carboxyl groups via a supramolecular cross-linking process by citric acid (CA) and trimesic acid (TMA). The role of surface chemistry (i.e., functional groups) and textural properties (i.e., pore size and surface area) in adsorption properties of these chitosan frameworks toward water vapor and dye was investigated. Extensive characterizations using N2 adsorption-desorption, contact angle measurements, differential scanning calorimetry, atomic force microscopy, and confocal microscopy were carried out to understand structure-property relationships of these framework materials. The dynamic vapor sorption analyzer measured water vapor sorption percentage (R %) values of 46.7, 43.9, and 41.5 for TMA1, CA1 framework materials, and chitosan, respectively. The calculated adsorption percentage values of dyes in aqueous solution were 69.7, 39.2, and 18.8 (R %) for TMA1, CA1, and chitosan, respectively.

| S-EPMC7469416 | biostudies-literature

Effect of Crystallinity on Water Vapor Sorption, Diffusion, and Permeation of PLA-Based Nanocomposites.

Project description:The effects of crystalline morphology and presence of nanoparticles such as cellulose nanofibers (CNFs), organically modified nanoclay (C30B), or a combination of both on water vapor sorption and diffusion in polylactide (PLA) were evaluated by a quartz spring microbalance (QSM). It was found that the large spherulite size induced by high-temperature processing leads to an increase in water sorption and a substantial reduction of diffusion with increasing crystallinity. Contrarily, small-sized spherulites, arising after low-temperature processing during solvent-casting, showed a different behavior with a slight decrease in both water vapor sorption and diffusion with increasing crystallinity. These observations suggest that solvent-casting at low temperatures should not be used to predict the properties a material will show after industrial-scale processing. From the analysis of the nanocomposite materials, it was concluded that nanoparticles affected the material's properties not only by themselves but also by modifying the crystalline morphology. Interestingly, this led to CNF showing similar performance to C30B, decreasing water diffusivity (21 vs 27%) on isothermally crystallized materials despite its less favorable geometry. Additionally, the incorporation of 1 wt % CNF and C30B decreased water vapor transmission rate (WVTR) by 24% under an amorphous state but by 44% in a crystallized state, which makes hybrid CNF/C30B composites a promising food packaging material.

| S-EPMC7331067 | biostudies-literature

Modulation of Water Vapor Sorption by Pore Engineering in Isostructural Square Lattice Topology Coordination Networks.

Project description:We report a crystal-engineering study conducted upon a platform of three mixed-linker square lattice (sql) coordination networks of general formula [Zn(Ria)(bphy)] [bphy = 1,2-bis(pyridin-4-yl)hydrazine, H2Ria = 5-position-substituted isophthalic acid, and R = -Br, -NO2, and -OH; compounds 1-3]. Analysis of single-crystal X-ray diffraction data of 1-2 and the simulated crystal structure of 3 revealed that 1-3 are isomorphous and sustained by bilayers of sql networks linked by hydrogen bonds. Although similar pore shapes and sizes exist in 1-3, distinct isotherm shapes (linear and S shape) and uptakes (2.4, 11.6, and 13.3 wt %, respectively) were observed. Ab initio calculations indicated that the distinct water sorption properties can be attributed to the R groups, which offer a range of hydrophilicity. Calculations indicated that the significantly lower experimental uptake in compound 1 can be attributed to a constricted channel. The calculated water-binding sites provide insights into how adsorbed water molecules bond to the pore walls, with the strongest interactions, water-hydroxyl hydrogen bonding, observed for 3. Overall, this study reveals how pore engineering can result in large variations in water sorption properties in an isomorphous family of rigid porous coordination networks.

| S-EPMC11232023 | biostudies-literature

On sorption hysteresis in wood: Separating hysteresis in cell wall water and capillary water in the full moisture range.

Project description:Moisture influences most physical wood properties and plays an important role in degradation processes. Like most other porous materials, wood exhibits sorption hysteresis. That is, the moisture content is higher if equilibrium is reached by desorption than if it is reached by absorption under the same ambient climate conditions. The mechanism of moisture uptake by wood are different in the hygroscopic and over-hygroscopic moisture ranges and due to methodical issues, most studies of sorption hysteresis have been performed in the hygroscopic range. In the present study, total sorption hysteresis was separated into hysteresis in cell wall water and capillary water respectively in the whole moisture range by a novel combination of experimental techniques. Wood specimens were conditioned to several high moisture contents using a new system based on the pressure plate technique, and the distinction between cell wall water and capillary water was done with differential scanning calorimetry. The results showed that sorption hysteresis in wood cell walls exists in the whole moisture range. The cell walls were not saturated with water until the whole wood specimen was saturated which contradicts the long-held dogma that cell walls are saturated before significant amounts of capillary water are present in wood.

| S-EPMC6857914 | biostudies-literature

Water vapor sorption and glass transition temperatures of phase-separated amorphous blends of hydrophobically-modified starch and sucrose.

Project description:This article contains water vapor sorption data obtained on amorphous blends of octenyl succinic acid-modified (denoted as hydrophobically modified starch; HMS) and sucrose (S) in the anhydrous weight HMS/S ratios between 100/0 and 27/75. The water vapor sorption data was obtained gravimetrically. The amorphous state of the blends was confirmed by X-ray diffraction. The glass transition temperatures of the phase-separated blends are listed; the blends show phase separation into a sucrose-rich phase and a HMS-rich phase, the composition of which varies with the blend ratios. The sucrose-rich phase is characterized by a glass transition temperature T g,lower that is 40 to 90?K lower than the glass transition temperature T g,upper of the HMS-rich phase.

| S-EPMC6172412 | biostudies-literature

Nanoporous composites prepared by a combination of SBA-15 with Mg-Al mixed oxides. Water vapor sorption properties.

Project description:This work presents two easy ways for preparing nanostructured mesoporous composites by interconnecting and combining SBA-15 with mixed oxides derived from a calcined Mg-Al hydrotalcite. Two different Mg-Al hydrotalcite addition procedures were implemented, either after or during the SBA-15 synthesis (in situ method). The first procedure, i.e., the post-synthesis method, produces a composite material with Mg-Al mixed oxides homogeneously dispersed on the SBA-15 nanoporous surface. The resulting composites present textural properties similar to the SBA-15. On the other hand, with the second procedure (in situ method), Mg and Al mixed oxides occur on the porous composite, which displays a cauliflower morphology. This is an important microporosity contribution and micro and mesoporous surfaces coexist in almost the same proportion. Furthermore, the nanostructured mesoporous composites present an extraordinary water vapor sorption capacity. Such composites might be utilized as as acid-base catalysts, adsorbents, sensors or storage nanomaterials.

| S-EPMC4143113 | biostudies-literature

Steady-state equation of water vapor sorption for CaCl<sub>2</sub>-based chemical sorbents and its application.

Project description:Green CaCl2-based chemical sorbent has been widely used in sorption refrigeration, air purification and air desiccation. Methods to improve the sorption rate have been extensively investigated, but the corresponding theoretical formulations have not been reported. In this paper, a sorption system of solid-liquid coexistence is established based on the hypothesis of steady-state sorption. The combination of theoretical analysis and experimental results indicates that the system can be described by steady-state sorption process. The steady-state sorption equation, μ = (η - γT) , was obtained in consideration of humidity, temperature and the surface area. Based on engineering applications and this equation, two methods including an increase of specific surface area and adjustment of the critical relative humidity (γ) for chemical sorbents, have been proposed to increase the sorption rate. The results indicate that the CaCl2/CNTs composite with a large specific surface area can be obtained by coating CaCl2 powder on the surface of carbon nanotubes (CNTs). The composite reached sorption equilibrium within only 4 h, and the sorption capacity was improved by 75% compared with pure CaCl2 powder. Furthermore, the addition of NaCl powder to saturated CaCl2 solution could significantly lower the solution's γ. The sorption rate was improved by 30% under the same environment.

| S-EPMC5040957 | biostudies-literature

Project description:Surface charring of wood is a one-sided thermal modification process that can be used to create a hydrophobic, durable surface to exterior claddings. Spruce (Picea abies L.) wood samples were charred with a hot plate and several time-temperature combinations while using simultaneous surface compression. Temperature profile, water sorption, cupping after water exposure and density profile were measured. Furthermore, changes in the microstructure and surface functional groups were investigated by scanning electron microscopy and photoacoustic FT-IR spectroscopy. Results show that surface charring notably improves the hydrophobicity measured by contact angle, water floating and dynamic vapour sorption. Increased holding time during charring reduced the sorption but at the same time increased the dimensional instability measured by cupping. The density profile showed a shifting density peak with more severe modification regimes, indicating a more porous surface. The PAS-FTIR showed increased aromaticity of the surface that was also present in the pyrolysis zone beneath the surface in samples modified with longer holding time. Higher modification temperature affected the sorption as well as cupping positively but it is possible similar results can be obtained with lower temperature and longer holding time.

| S-EPMC6266808 | biostudies-literature

Large datasets of water vapor sorption, mass diffusion immersed in water, hygroscopic expansion and mechanical properties of flax fibre/shape memory epoxy hygromorph composites.

Project description:This data article presents four experimental sets of results related to flax fibre composites with epoxy shape memory polymer matrix: water vapor absorption, mass diffusion immersed in water, hygroscopic expansion, mechanical properties. The water vapor absorption tests are described in raw data related to four types of laminates with weights measured at different relative humidity (0%, 9%, 33%, 44%,75%, 85% and 100%). The mass diffusion experiments are related to weights of immersed samples over time. The unidirectional composite hygroscopic expansion is also measured along the fibre longitude and transverse directions. The mechanical properties of flax composite at various temperatures (20°C, 40°C, 60°C, 80°C and 100°C) and humidity environments (50% and immersed) are also described. Load-displacement diagrams of the hygromorph composites are converted into stress-strain diagrams via a compliance calibration, from which the tensile moduli are extracted. The data presented in this article can provide a benchmark for the development of new models, or for the determination of other properties via post processing. The detailed interpretation of the data can be found in [1]. The data is available in the Mendeley Data repository at [2].

| S-EPMC9234088 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data