Water Transport Properties Research Articles

Water Transport and Thermomechanical Properties of Ti3C2Tz MXene Epoxy Nanocomposites.

Herein, we present the fabrication of dispersed, 5.0 wt % (1.74 vol %) Ti3C2Tz MXene epoxy nanocomposites (NCs), and report on their water transport and mechanical properties. To make the composites, Li+ ions between Ti3C2Tz MXene multilayers, MLs, present after the etching step were exchanged with either 12-aminolauric acid, ALA, or di(hydrogenated tallow)benzyl methyl ammonium chloride, DHT. After drying, the resulting ML powders were added at room temperature to the epoxy resin (diglycidyl ether of bisphenol A), followed by the curing agent, triethylenetetramine. The NCs were characterized by X-ray diffraction, thermogravimetric analysis, dynamic vapor sorption, dynamic mechanical analysis, scanning and transmission electron microscopies, and infrared spectroscopy. From XRD, the lack of signature MXene basal peaks, as well as evidence of exfoliation supported by TEM micrographs, we conclude that the MXene ML had indeed been intercalated by the epoxy. The distribution of the exfoliated multilayers, MLs, however, was not uniform. Nevertheless, our relative permeabilities, with a 1.74 vol % loading, are 5 times lower than results obtained in the carbon- or clay-reinforced epoxy NC literature. The lower permeabilities are due to reductions in both solubilities and diffusivities relative to the neat polymer. In the case of DHT, the water solubility at all temperatures was almost halved. The mechanical properties and thermal stability are found to be slightly improved with the addition of DHT-MXene. As far as we are aware, this is the first report of exfoliation of MXene in an epoxy matrix. Additionally, this study is the first to measure the diffusion of water in MXene epoxy NCs. More work on better dispersion of the MLs is indicated and ongoing.

How the chemical structure of the plasma-deposited SiOx film modifies its stability and barrier properties: FTIR study

Organosilicon thin films issued from the gas mixture of oxygen and hexamethyledisiloxane (HMDSO), 2,4,6,8-tetramethylcyclotetrasiloxane (TMCTS), or fluorotriethoxysilane (FTEOS) deposited on polycarbonate (PC) substrate were obtained thanks to a RF plasma source. The chemical structure of the two types of inorganic SiOx (HMDSO/O2, TMCTS/O2) and fluorinated SiOxCyFz (FTEOS/O2, FTEOS/O2/TMCTS) coatings have been investigated by FTIR and XPS spectroscopies, and wettability measurement. Network structure and density of SiOx and SiOxCyFz thin films were discussed as a function of the νSiOSi band shifting observed in their respective FTIR spectra. The influence of various plasma parameters (such as discharge power, precursor/O2 ratio and, duration) on the film properties was studied in order to optimize the growth of both inorganic and fluorinated thin films. The ageing of such layers either at ambient atmosphere or even at reduced pressure showed a chemical alteration of the thin films surface and bulk, which stabilized after 15 days of storage. Such phenomenon is explained by the hydrophobicity recovery that may induce the observed network alteration. Water and oxygen permeation and transport properties of treated PC films were correlated with the coating structure and composition; then TMCTS was identified as the most efficient precursor for enhancing water barrier property. Furthermore, the permeation properties of these deposits seem to be more controlled by the material density than by their chemistry.

Development of Water Vapor Transport Resistance Protocol and Analysis

W. L. Gore and Associates, Inc. (Gore) supports the lowest $/kW fuel-cell systems through development of thin, reinforced membranes, ca. 10 µm or less. Thin membranes decrease cost by reducing material content and facilitate higher performance through increased proton conductance and faster water transport. However, it has been postulated that an interfacial water transport resistance, significantly different than the bulk resistance, will dominate for thin membranes. For example, in a previous study, the interfacial effect accounted for half of the total transport resistance for a 10 µm membrane at 30% RH1. Understanding water transport through the membrane is necessary for system-level models to design optimal operation strategies. Gore implemented a protocol and analysis method for characterizing water transport properties of cation exchange membranes. Water flux is driven across the membrane by a chemical-potential gradient at different water activity levels. The water balance is tracked by monitoring the dew point at cell inlet and outlet and closes within 10%. Fick’s law is used to normalize flux data by the activity gradient across cell and inverted to calculate a total transport resistance. Cell hardware with 5 cm2 active area and straight-channel flow field configuration was used. Further details will be discussed in this presentation. Using this method, the bulk permeability of extrusion cast Nafion 11x films is 0.16 µmol/cm/s at 30% relative humidity (RH) and 95 °C, which is in agreement with literature at similar conditions1. An Evaluating the Measurement Process (EMP) study was used to quantify the amount of variation arising from measurement device and operator. With a sample size of 4, the protocol is able to detect a difference in total water transport resistance greater than 0.3 m2-s/mol. The protocol was used to study a series of 700 EW cast film thicknesses from 7 – 70 µm to separate individual contributions to the total water transport resistance, RTotal = RGas + RBulk + RInterfacial. The gas-phase transport resistance, RGas, was separated using hydrogen and nitrogen carrier gasses. The bulk water transport resistance, RBulk, is equal to thickness divided by bulk permeability. Figure 1a shows bulk permeability increases with higher water content, as expected due to the percolating network of water conducting channels2. Typically, any residual resistance is attributed to an interfacial effect, which has been rationalized by the orientation of the hydrophobic backbone toward surface2. In this study, the interfacial resistance is indistinguishable from zero. The equivalent thickness of membrane interface is shown in Figure 1b as a function of RH. ACKNOWLEDGMENTS The authors gratefully acknowledge the contribution of the Electrochemical Products team of W. L. Gore and Associates, Inc. REFERENCES Kienitz, B., Yamada, H., Nonoyama, N. & Weber, A. Z. Interfacial Water Transport Effects in Proton-Exchange Membranes. J. Fuel Cell Sci. Technol. 8, 011013-1-011013-7 (2011).Kusoglu, A. & Weber, A. Z. New Insights into Perfluorinated Sulfonic-Acid Ionomers. Chem. Rev. 117, 987–1104 (2017). Figure 1

Bioinspired Janus Textile with Conical Micropores for Human Body Moisture and Thermal Management.

Excessive sweat secreted from the skin often causes undesired adhesion from wetted textiles and cold sensations. Traditional hydrophilic textiles such as cotton can absorb sweat but retain it. A hydrophobic/superhydrophilic Janus polyester/nitrocellulose textile embedded with a conical micropore array with a hydrophilic inner surface that can achieve directional liquid transport (with an ultrahigh directional water transport capability of 1246%) and maintain human body temperature (2-3 °C higher than with cotton textiles) is demonstrated. When the hydrophobic polyester layer with large opening of hydrophilic conical micropores contacts the liquid, the Janus polyester/nitrocellulose textile can pump it to the superhydrophilic nitrocellulose layer through the hydrophilic conical micropores driven by capillary force. The Janus polyester/nitrocellulose textile can weaken undesired wet adhesion and heat loss due to the removal of liquid. The water wicking and air permeability of the Janus polyester/nitrocellulose textile is comparable to those of traditional cloths. This study is valuable for designing of functional textiles with directional water transport properties for personal drying and warming applications.

Investigation and modelling of the water transport properties in unfilled EPDM elastomers

The water sorption properties (i.e. diffusivity and solubility) of three unfilled vulcanized EPDMs were investigated in wet atmosphere (typically between 0 and 95% RH) and in pure distilled water (denoted as 100% RH) at 70 °C with an IGAsorp dynamic sorption analyzer. In the 0–0.5 activity range, all EPDMs obey to the usual Fick and Henry's laws. In contrast, at activities higher than 0.5, the water sorption behavior of all EPDMs deviates from these two laws because of the formation of water clusters. Park's equation was used for simulating accurately the sorption isotherms and thus, accessing Henry's constant and the average size of water clusters. In wet atmospheres, clusters would be composed of about 8 ± 4 molecules corresponding approximately to the size of free volume holes. In contrast, in pure distilled water, clusters consist in a much larger number of water molecules (between 55 and 71) presumably because of an exacerbated swelling of EPDM samples. Thus, immersion in water solution is more drastic than exposure to fully saturated wet atmosphere. The impact of the EPDM formulation (nature and content of crosslinking agent) on these experimental results is clearly of the second order of magnitude.

The interactions between water molecules and C-S-H surfaces in loads-induced nanopores: A molecular dynamics study

Molecular dynamics simulations are used to investigate the interactions between water molecules and C-S-H surfaces and transport properties of water confined in the nanopore. Firstly, a C-S-H model based on experimental results is constructed, then a nanopore induced by tensile loading is taken into account for the first time. Structural and dynamical properties of confined water and interactions between water solution and C-S-H surface are further investigated at the molecular level. Water molecules gathering in the vicinity of C-S-H surfaces perpendicular to Z direction present peculiar structural and dynamic characteristic: layer structure, high density, obvious orientation preference, and low diffusion coefficient. The silicate chains are connected with water molecules by the high-strength hydrogen bonds formed among water and non-bridge oxygen atoms (ONB), bridge oxygen atoms (OB) in silicate chains, while surface calcium ions sheets are prone to attract oxygen atoms in water molecules. The special structural and dynamic features are mainly determined by the interactions among water, silicate chains, and surface calcium ions sheets. Due to the lack of strong constraint from the C-S-H substrates and driven by water molecules in the nanopore, the surface calcium ions diffuse more rapidly than those constrained inside of the C-S-H gel and could diffuse into the nanopore full of water molecules.

MECHANICAL AND WATER TRANSPORT PERFORMANCE OF SUSTAINABLE GEOPOLYMER COMPOSITE USING BINARY BLENDS OF POZZOLANIC MATERIALS

The focus of the researchers has now shifted towards the geopolymer based materials as it considered as sustainable alternative to the existing cementitious materials. This paper attempts to incorporate the binary blend of pozzolanic material to develop geopolymer composite and understand it’s mechanical and water transport performance as a building material. The combination of bottom ash and rice husk ash with fly ash as a common binder was used for development of geopolymer composite. Replacement levels of both bottom ash and rice husk ash was kept at 40%, 30% and 20% of total solid proportions. Also, the molarity of NaOH was provided at 12 M and 14 M levels respectively. The results showed that the blend of FA-BA blend to be better performed against the blend of FA-RHA blend for their mechanical and water transport properties. The compressive strength of the geopolymer composite having blend of fly ash and bottom ash reached to the value of 41.49 MPa due to its suitable Si/Al ratio for geopolymerization reaction, which is quite remarkable. Also, the results of water transport performance shows the blend of FA-BA to be 15-20% more resistant to percolation of water as compared to FA-RHA blended geopolymer composite, thus lowering the risk of damages to the structures.

Graphite/UPE Nanocomposite: Transport, Thermal, Mechanical and Viscoelastic Properties

This chapter presents the preparation and characterization of some unique properties of nanocomposites by dispersing graphite flakes in commercial unsaturated polyester (UPE) matrix. The composite was prepared by a novel method with the use of solvent swelling technique. Three different specimens of UPE/graphite nanocomposites were fabricated with addition of 1, 2 and 3 wt% of graphite flakes. Except mechanical, viscoelastic and thermo gravimetric properties, transport properties like electrical conductivity, thermal conductivity and water transport properties were studied for the first time. Graphite flakes propose enhanced properties to the composites suggesting homogeneous distribution of the nanofiller in the matrix and strong interaction with the matrix. 2wt% nanofiller loading showed superior essential characteristics and after that the properties reduced may be due to the nucleating tendency of the nanofiller particles. The XRD pattern showed the compatibility of the graphite flakes by introducing a peak around 26.550 in the nanocomposites. SEM Properties are also in agreement with the compatibility. Nanocomposite with 2wt% graphite also showed remarkable enhancement in transport, mechanical, viscoelastic and thermo gravimetric properties. So by introduction of a small quantity of graphite endow the new class of multiphase nanocomposites with inimitable structure and tremendous application.

Ion and water transport properties of cation exchange membranes prepared by heavy-ion-track grafting technique

ABSTRACT For high-performance electrodialysis of saline water, cation exchange membranes (CEMs) that actively transport Na+ and restrict water permeation are required. In this study, we prepared novel CEMs by a heavy-ion-track grafting technique and measured their membrane resistance and water permeation flux as transport properties. The prepared nanostructured CEMs exhibited lower resistance and lower water flux than the commercial CEM. Na+ ions were efficiently transported through their unique one-dimensional ion channels (low resistance), while water transport was suppressed due to the very low water uptake of the CEMs. These results demonstrated the high potential of these nanostructured CEMs for use in practical saline water electrodialysis.

Eco-friendly concrete with scrap-tyre-rubber-based aggregate – Properties and thermal stability

Increasing amount of waste tyres represents a global problem as tyres can pose a risk to the environment if not treated properly. Recycling of waste tyre rubbers in civil engineering as aggregate in cement concrete can be an effective environmental and economic approach. As problems associated with the use of waste tyre rubber in concrete production are not completely understood, a detailed analysis of rubber concrete prepared from used tyre rubber-based aggregate involving testing of its mechanical, basic physical, microstructural, hygric and thermal properties, and behaviour after exposure to elevated temperatures is presented in this paper. Testing of mechanical performance included measurement of compressive strength, flexural strength, secant and dynamic modulus of elasticity. Thermal conductivity was determined in the dependence on moisture content, from the dry to fully water saturated state. Dry volumetric heat capacity was also tested. Specific attention was paid to the hygric performance of rubberized concrete that was characterised by the water and water vapour transport parameters. Investigation of concrete properties after its thermal exposure included testing of mass loss, mechanical resistance, bulk density, and thermal conductivity that was tested as property having direct relation to concrete structural parameters. The use of scrap-tyre-rubber aggregate resulted in a decrease of the unit weight, worsening in mechanical parameters and a significant reduction in thermal conductivity of prepared rubberized concrete. Rubber-based aggregate almost did not affect water transport properties, while water vapour transport properties increased with rubber amount in the mix. No significant changes on concrete characteristics related to rubber incorporation occurred at temperatures up to 300 °C. However, after exposure to 400 °C, significant changes in measured concrete properties were observed, which was in line with the thermogravimetric analysis of the used tyre-based rubber. Nevertheless, based on rubberized concrete functional properties at common ambient conditions it can be considered as an alternative lightweight material, bringing benefits to the environment and economy as it is produced from crap available in a large amount and at a negligible cost.

Transport Properties of Water–Triethylamine Fluid Mixtures Calculated Using Molecular Dynamics

The knowledge of transport properties is crucial to design new devices in electronic and biotechnological industries. Due to the fast growth of the processor speed, molecular simulations have become a robust method to calculate the transport properties. In this work, we show numerical methods such as Green–Kubo formalism to estimate transport properties applied to real liquids. We focus on the study of shear viscosity and thermal conductivity of a water (H2O) and triethylamine (C6H15N) solution which has a potential application for heat exchange inside electronic circuits. The radial distribution function and hydrogen-bond analysis have been made at a broad range of temperatures and mole fractions using equilibrium molecular dynamics, and comparisons with experimental data in the literature have been reported.

Water Uptake and Transport Properties of La1-xCaxScO3-α Proton-Conducting Oxides.

In this study, oxide materials La1−xCaxScO3−α (x = 0.03, 0.05 and 0.10) were synthesized by the citric-nitrate combustion method. Single-phase solid solutions were obtained in the case of calcium content x = 0.03 and 0.05, whereas a calcium-enriched impurity phase was found at x = 0.10. Water uptake and release were studied by means of thermogravimetric analysis, thermodesorption spectroscopy and dilatometry. It was shown that lower calcium content in the main phase leads to a decrease in the water uptake. Conductivity was measured by four-probe direct current (DC) and two-probe ascension current (AC) methods at different temperatures, pO2 and pH2O. The effects of phase composition, microstructure and defect structure on electrical conductivity, as well as correlation between conductivity and water uptake experiments, were discussed. The contribution of ionic conductivity of La1−xCaxScO3−α rises with decreasing temperature and increasing humidity. The domination of proton conductivity at temperatures below 500 °C under oxidizing and reducing atmospheres is exhibited. Water uptake and release as well as transport properties of La1−xCaxScO3−α are compared with the properties of similar proton electrolytes, La1−xSrxScO3−α, and the possible reasons for their differences were discussed.

Hybrid Materials Based on MF-4SC Membranes and Carbon Nanotubes: Transport Properties and Characteristics of DP-sensors in Hydrophobic Amino Acid Solutions

Perfluorinated sulfonated cation-exchange membranes MF-4SC containing 0.5–3.0% of carbon nanotubes (CNTs) have been synthesized. A correlation between the water uptake and transport properties of the membranes in the K+-form and the sensitivity of DP-sensors (with the analytical signal in the form of a Donnan potential) to the analyte and interfering ions in solutions of hydrophobic amino acids (alanine, valine, and phenylalanine) has been found. Hybrid membrane samples that provide the highest sensitivity of DP-sensors to amino acid cations and zwitterions and the lowest sensitivity to hydroxonium ions at pH < 7 in a concentration range of 1.0 × 10–4–1.0 × 10–1 M have been selected. Membrane modification has led to a decrease in the relative error and the relative standard deviation in the determination of amino acid ions by a factor of 3 and 1.5, respectively.

Optimization of tin oxide-based electron transport layer for perovskite solar cells

The electron transport layer is the key material in perovskite solar cells (PSCs), and tin oxide (SnO₂) has been considered as an ideal electron transport material. The SnO₂ prepared by the low temperature sol-gel method suffers from low crystallinity and poor electron transport properties. In this paper, the crystallinity of SnO₂ was increased by adding water as solvent addictive to sol-gel precursor, which finally increased the efficiency of solar cells. SnO₂-based electron transport layer was prepared through a sol-gel method and the preparation conditions were optimized. It was found that adding proper amount of water as the solvent addictive to prepare SnO₂ sol-gel under 80 ℃ for 24 h benefits the hydrolysis of SnCl₂, enhancing the reaction and crystallinity of SnO₂. Finally, the SnO₂ film was prepared via spin-coating annealing method. With the increase of water, both the crystallinity and electron transport properties were enhanced. When 150 μL of water was added, the obtained SnO₂ layer was compact and smooth. The short-cut circuit current was 22.77 mA/cm^2, the open circuit voltage was 1.037 V, the filling factor was 0.492 and the photo-electron conversion efficiency was 11.617%. However, excessive water addictive leads to more defects in the prepared SnO₂ films and finally leads to the decrement of efficiency.

Stone consolidation with SiO2 nanoparticles: Effects on a high porosity limestone

This study deals with the effect of a water colloidal suspension of nanosilica applied as a consolidant on a porous limestone. The stone performances were investigated by several analyses and tests. They fulfilled basic requirements such as consolidating effectiveness and compatibility with the original colour and water transport properties. A point of weakness was found in the behaviour under the salt crystallisation test, showing a decreased durability for the treated stone. The modification of the porous structure accounts for this result, suggesting that the distribution of the nanoparticle fillers into the stone substrate should be improved.

Scalable and rapid preparation of Janus fabric by trans-printing method for efficient oil/water emulsion separation

The old-fashioned yet effective trans-printing method was adopted to prepare Janus fabric in the study. Nonwoven cotton fabric was firstly immersed in tetrahydrofuran solution containing P(DMAEMA-co-TMSPMA), a polymer synthesized by copolymerization between N, N-dimethylaminoethyl methacrylate (DMAEMA) and 3-(trimethoxysilyl)propylmethacrylate (TMSPMA), followed by thermal treatment, thus endowing the fabric with the demulsification property. Next, one side of the above prepared fabric was overlapped and rolled with donor fabric containing PDMS-g-TMOS, a polymer synthesized by thiol/ene click reaction between multi-vinyl poly(dimethylsiloxane) (vinyl-PDMS) and 3-mercaptopropyltrimethoxysilane (MPTMOS). The PDMS-g-TMOS polymer infiltrated into the fabric cured with P(DMAEMA-co-TMSPMA) to a certain depth, followed by thermal treatment. Thus, the resultant fabric had both the superhyrophilic side for oil coalescence and the superhyrophobic side for oil permeation. The Janus fabric structure was confirmed by metalloscope, unidirectional water transport property (UDWT), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). When the prepared fabric was used to separate model oil hexadecane (HD) from oil-in-water emulsion, the maximum separation speed was 134.5 kg h−1 m−2. The recovery rate of HD respectively reached 96.0% after 60 min and 99.9% after 150 min. The Janus fabric prepared by the trans-printing method is particularly suitable for industrial production and of great industrial value.

Morphology, mechanical, and water transport properties of melt blended EVOH/PVOH films

ABSTRACTHerein, we report for the first time the successful preparation of ethylene–vinyl alcohol (EVOH)/poly(vinyl alcohol) (PVOH) blends by a melt blending process for PVOH volume content ranging from 0 to 30%. Thermal stability up to 270 °C was maintained for all blends. The blends morphology consisted in spherical low size PVOH domains homogeneously dispersed in the EVOH matrix with good interfacial properties. An increase of the mean size of the PVOH domains (from 0.3 to 1.2 μm) and of the size distribution was evidenced as the PVOH content increased. The contribution of each phase to the water sorption and diffusion was clearly demonstrated. The impact of water uptake was investigated on the chains mobility by using Gordon–Taylor law and on the mechanical properties of the blends with respect to the reference polymers. It was pointed out that the reinforcing effect of PVOH phase decreased as the water activity increased. However, a significant elongation at break was maintained, underlining the major role played by the EVOH continuous phase at high water activity. Finally, it was shown that adding PVOH to EVOH up to 15 vol % allowed strengthening the material at low water activity and keeping interesting elongation at break and barrier properties at high water activity. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 838–850

Nylon-6/Ti3C2T z MXene Nanocomposites Synthesized by in Situ Ring Opening Polymerization of ε-Caprolactam and Their Water Transport Properties.

Clay-reinforced nylon-6 nanocomposites (NCs)-characterized by the full exfoliation of the nanoreinforcement-were introduced in the marketplace in the 1990s. Herein, we demonstrate, for the first time, that Ti3C2T z MXene can be incorporated into nylon-6 to synthesize melt-processable nanocomposites with excellent water barrier properties (94% reduction in water vapor permeation). To intercalate the ε-caprolactam monomer between the MXene multilayers, the latter were first treated with 12-aminolauric acid, a low-cost, nontoxic, biodegradable, and long shelf life compound. Upon heating to 250 °C, in the presence of 6-aminocaproic acid, in situ polymerization occurred, yielding melt-processable nylon-6/MXene NCs that were, in turn, studied by thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, scanning and transmission electron microscopy, infrared spectroscopy, and dynamic vapor sorption analysis. Using the latter, moisture-sorption isotherms of a neat and a 1.9 vol % NC, at 60 °C, were fit to the Guggenheim, Anderson, and de Boer equation. Solubility, permeation, and diffusion coefficients of water through the NCs were measured as a function of temperature and found to be the lowest ever reported for nylon-6, despite the fact that, at ∼1.9 and 5.0 vol %, the MXene loads were relatively low. This record low diffusivity is ascribed to the very large aspect ratios-500 to 1000-of Ti3C2T z flakes and their dispersion. The water permeation rate is a factor of 5 lower than the best reported in the much more mature nylon/clay field, suggesting lower values can be achieved with further optimization. Lastly infrared spectroscopy spectra of neat and NC samples suggest the surface terminations of the 12-Ti3C2T z flakes bind with nylon-6, limiting water adsorption sites, resulting in reduced solubility in the NC films.

Structure and Transport Properties of Water and Hydrated Ions in Nano‐Confined Channels

AbstractNano‐confined flow is ubiquitous in modern engineering and biomedical applications. As the peculiar phenomena of nano‐confined flow were continuously reported and traditional theories failed to describe them accurately, simulation efforts have been made to gain deeper insight. The objective of this paper is to provide an overview of the recent progress on nano‐confined flow, including water flow and hydrated ions transport. This report starts with the water behavior under nano‐confinement, summarizing the water structures, flow properties and their dependence on wall wettability, channel size, etc. The report also presents the efforts made to modify the existing theories to describe nano‐confined flows. Then, the report goes to the hydrated ions. The dehydration process of hydrated ions and ions sieving are discussed in detail, and the effects of membrane surface charge, grafting functional groups, and external field on ions transport are reviewed. In this Progress Report, the transport properties of water and hydrated ions in nano‐confined channels are highlighted, which is critical to the design and application of nanofluidic devices, such as nanofiltration membranes, biosensors, and other related fields.

Thermal and hygric properties of biomaterials suitable for interior thermal insulation systems in historical and traditional buildings

Historical and traditional buildings account for 10–40% of the building stock in various countries and regions. Retrofitting of their building envelopes aimed at the improvement of thermal performance is often feasible using interior thermal insulation systems only. The effectiveness of systems without vapor barrier depends on the application of modern insulation materials with enhanced water transport properties contributing to fast liquid moisture redistribution and mitigating the risks related to water vapor condensation. In this paper, thermal and hygric properties of several biomaterials potentially applicable as thermal insulation boards on the interior side of historical building envelopes are investigated. The obtained experimental data include all transport and storage parameters necessary for appropriate hygrothermal- and energy-related assessment of buildings provided with interior thermal insulation systems using advanced computer simulation tools. Wood fiberboard, flax fibers, hemp fibers, jute fibers, and sheep wool are found to have, at the same time, low thermal conductivity (∼0.05 W m−1 K−1) and high moisture diffusivity (1.1 × 10−6 – 1.2 × 10−5 m2 s−1) which can classify them as good candidates for the use in interior thermal insulation systems without water vapor barrier. They exhibit convenient water vapor diffusion parameters and hygroscopic properties as well, which favors their use on the interior side. The natural origin presents another benefit. In a comparison with conventional materials (calcium silicate, hydrophilic mineral wool) having similar thermal and hygric properties, they bring more harmony to the process of retrofitting historical building envelopes.