Vapor Sorption Research Articles

Thermal and Moisture Management in the Microclimate of Socks for Diabetic Foot Care: The Role of Mohair-Wool Content

In diabetic patients, optimised plantar health necessitates meticulously designed hosiery. These specialised socks facilitate a healthy microclimate at the skin–textile interface. This requires that stable conditions of temperature and humidity are maintained during wear. This study investigated the thermal resistance and moisture management properties of socks for diabetics. Fabrics and socks were evaluated on the Alambeta and thermal foot manikin instruments and in wear trials. A novel in vitro method, mimicking in-use conditions, was employed to validate findings and assess sock performance during wear. Fabric structure, especially thickness, had a greater impact on thermal resistance than fibre composition, suggesting that socks with different levels of thermal resistance can be customised according to individual preferences. In terms of moisture management, mohair–wool socks outperformed polyester socks, maintaining significantly lower humidity between the skin and the sock, and meeting the requirement to prevent the drying out of the microclimate significantly better. The enhanced moisture vapour sorption exhibited by the mohair–wool fabric contributes to this effect. Overall, the findings suggest that mohair–wool is an excellent fibre choice for diabetic socks, due to its unique moisture management properties and the possibility to tailor thermal properties through fabric structural design.

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

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.

The Effect of Macromonomer Surfactant Microstructure on Aqueous Polymer Dispersion and Derived Polymer Film Properties.

Water-borne coatings were prepared from poly(methyl methacrylate-co-butyl acrylate) latexes using different methacrylic acid containing macromonomers as stabilizers, and their physical properties were determined. The amphiphilic methacrylic acid macromonomers containing methyl, butyl, or lauryl methacrylate as hydrophobic comonomers were synthesized via catalytic chain transfer polymerization to give stabilizers with varying architecture, composition, and molar mass. A range of latexes of virtually the same composition was prepared by keeping the content of methacrylic acid groups during the emulsion polymerization constant and by only varying the microstructure of the macromonomers. These latexes displayed a range of rheological behaviors: from highly viscous and shear thinning to low viscous and Newtonian. The contact angles of the resulting coatings ranged from very hydrophilic (<10°) to almost hydrophobic (88°), and differences in hardness, roughness, and water vapor sorption and permeability were found.

Comprehensive analysis of water vapor sorption kinetics and mechanisms using biosorbent pellets from canola meal and oat hull

Agricultural residues, specifically canola meal (CM) and oat hull (OH), have been innovatively utilized to develop biosorbents for sorbing water vapor from the air. These biomaterials are comprised of hydrophilic functional groups that effectively perform air dehydration. Air, being non-polar, was used as a model gas in this study to simulate gas dehydration. In the current research, these materials were formed into pellets to produce high-quality biosorbents with controlled size, shape, and enhanced moisture uptake capacity. CM (309.48 mg/g) and OH (233.07 mg/g) pellets had higher or comparable water sorption capacities than commercialized adsorbents used for drying gases. The mixed-order kinetic model described the sorption process well and identified both mass transfer and sorption on active site steps (R 2 > 0.991 and χ 2 < 16.0). Regarding the OH pellet, sorption on active sites was the predominant kinetic mechanism at the beginning, followed by intraparticle diffusion until equilibrium. However, sorption on CM pellets was delayed at 4.2 min at the initial stage, owing to the external mass transfer resistance; then, intraparticle diffusion controlled the process until equilibrium. Adding sodium lignosulfonate (LSNa) lowered the initial sorption rate but enhanced the water uptake and strength of pellets. The addition of LSNa resulted in a 25% and 14% increase in the water uptake capacity of oat hull and canola meal pellets, respectively; conversely, it also caused an increase in the delay time for sorption on CM pellets at the beginning of the process, extending it to 9.50 min.

Eutectic mixtures containing the active pharmaceutical ingredient ezetimibe: Phase diagrams, solid state characterization and dissolution profiles

Cardiovascular disease represents the leading cause of death worldwide, according to the World Health Organization (WHO) report. One of the treatment strategies is the use of the drug ezetimibe (EZT). This drug is a cholesterol absorption inhibitor with low aqueous solubility, which affects its therapeutic efficacy. The purpose of this paper was to obtain eutectic materials of EZT with methylparaben (MPB), salicylic acid (SCA) and nicotinamide (NTM) coformers, and to study their phase diagrams, dissolution properties and hygroscopicity to assess possible enhancements. Phase and Tamman diagrams were constructed using differential scanning calorimetry (DSC) results. The eutectic materials were characterized by powder X-ray diffraction (PXRD) and polarized light optical microscopy (OM). The hygroscopicity of the materials was assessed at different relative humidities (RH) through dynamic vapor sorption (DVS). The dissolution study was conducted with the materials in powder form, with paddle dissolution, rotating at 50 rpm, in 900 mL of aqueous buffer solution at pH 6.8 and 37 °C. The phase diagrams demonstrated that EZT formed eutectic systems with eutectic molar fractions of 0.59, 0.67 and 0.69 for EZT-SCA, EZT-NTM and EZT-MPB, respectively. The three eutectic materials are characterized as microcrystalline conglomerates of their components. In terms of the hygroscopic behavior of EZT at different RHs, eutectic materials demonstrated lower susceptibility to monohydrate formation compared to the anhydrous form. In dissolution studies, EZT-SCA and EZT-MPB solubilized EZT in amounts 22 % higher than the pure drug in 15 min. On the other hand, EZT-NTM eutectic suppressed the dissolution of EZT down to 56 % at the same time. The results indicated the possibility of obtaining materials with enhanced properties using eutectic mixtures, with improved dissolution rates and hygroscopic stability.

Cellulose acetate/chitosan composite film loaded with ground cinnamon for active packaging: water vapor sorption kinetic, compounds release, and antimicrobial effect

This study evaluated structural, physical, and water sorption properties of cellulose acetate/chitosan composite film incorporated with ground cinnamon as an antimicrobial. The controlled release of antimicrobial compounds and antimicrobial effects on Escherichia coli and Staphylococcus aureus were also monitored. The composite film formed highly porous and fibrous materials with higher thermal resistance. A higher ratio of chitosan in the film improved the swelling degree and water-vapor absorption capacity but reduced adsorption rates. Consequently, antimicrobial compounds, including eucalyptol, naphthalene, and β-caryophyllene, were more quickly released from the composite film with a larger chitosan ratio, affecting stronger antimicrobial effects. The inclusion of ground cinnamon with residual fat content in the film contributed to an extended inhibition of microbial growth in an indirect packaging system. Understanding the chitosan/cellulose acetate ratio in the film composite formation and the incorporation of ground cinnamon is important to control the compounds' release and generate long-term antimicrobial effects of active packaging materials on fresh food products.

Heat and mass transfer analysis of desiccant-coated heat exchanger with desiccants and metal-organic framework for bus air conditioning applications

Desiccant-coated heat exchangers (DCHEs) in air conditioning offer advantages like independent temperature and humidity control, reduced energy consumption, and high performance. However, the availability of desiccants with high water adsorption and low thermal energy requirements is limited. The present study proposes that aluminum fumarate (Al-Fum) MOF-coated heat exchangers will outperform conventional desiccants, especially at low regeneration temperatures (around 50°C). In order to evaluate this hypothesis, the performance of DCHEs was evaluated with a validated analytical model for different solid desiccant coatings: silica gel, zeolite, and Al-Fum MOF. Water vapor sorption characteristics, heat and mass transfer, and adsorption and desorption capacities were determined. The results showed that the Al-Fum MOF-coated heat exchanger outperformed silica gel and zeolite at low regeneration temperatures under adiabatic conditions. The MOF exhibited superior water uptake capacity (0.39 g/g) between 20% and 80% RH compared to the other studied conventional desiccants. Moreover, the MOF achieved the lowest outlet air temperature. At 19.5 g/kgda, the MOF demonstrated higher adsorption rates (4 % and 0.3 %) than zeolite and silica gel. These findings highlight the potential of Al-Fum MOFs as energy-efficient solutions for controlling indoor air humidity, particularly for latent-sensible heat separation systems with conventional vapor compression bus air-conditioning systems.

Modified spinel ferrite–based composite membranes with highly proficient photocatalytic activity

As an environmentally friendly and economically feasible approach for wastewater treatment, new photocatalytic composite membranes have been developed. For improved photocatalytic performance, zinc-based spinel ferrite (ZnAlFe0.94Sm0.06O4) was produced by substituting Fe cations with Al3+ and doping with samarium cations. Inorganic nanoparticles have been introduced as filler into the PVDF polymer matrix to aid in the recovery of the photocatalysts. By employing the electrospinning technique, composite membranes with various filler contents were produced. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), and a vibrating-sample magnetometer (VSM) were used to assess their structural, morphological, and magnetic characteristics. The mechanical behavior and water vapor sorption isotherms of the composite membranes were evaluated in comparison to the pristine PVDF membrane. The photocatalytic efficiency of the composite membranes was assessed by the degradation of an organic pollutant (methylene blue). Thus, the degradation efficiency of the composite membranes ranged from 80 to 96 %, and the kinetic assay revealed that the rate constant with the greatest value was k = 5.413 × 10−3 min−1 in optimal conditions.

Process development in Quality‐by‐Design paradigm for anti‐solvent aided crystallization: impact of crystallization parameters on particle morphology and dissolution behaviour of Dexlansoprazole active pharmaceutical ingredient

AbstractBACKGROUNDIn this work, a process development study for the crystallization step of dexlansoprazole API has been demonstrated under the Quality‐by‐Design (QbD) paradigm. Dexlansoprazole (crystalline) samples prepared under different crystallization conditions of reactor temperature and addition time of anti‐solvent were subjected to solid‐state characterization with variety of analytical techniques, including X‐ray powder diffraction (XRPD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic vapour sorption (DVS), scanning electron microscopy (SEM), particle size distribution (PSD) by laser diffraction and intrinsic dissolution rate (IDR).RESULTSThe crystalline samples were observed to have identical polymorphic phase integrity but differed in their physical characteristics. The particle size distribution and microscopy data collectively elucidated the particle growth kinetics and the extent of agglomeration could be correlated to crystallization conditions, namely reactor temperature and addition time of anti‐solvent. The intrinsic dissolution rate of samples was in good agreement with the morphological properties.CONCLUSIONAn empirical model has been proposed for intrinsic dissolution rate correlating with crystallization process parameters. In conclusion, it was possible to elucidate the impact of crystallization parameters on the solid‐state behaviour of dexlansoprazole for development of appropriate pharmaceutical dosage forms. © 2024 Society of Chemical Industry (SCI).

Effects of Micropores on the Vapor Sorption Isotherm and Structural Parameters Characterization of Kaolinite

The vapor sorption isotherm (VSI) of soil serves as a basic tool in geotechnical engineering, widely employed for characterizing the structural parameters of soil. Micropores are commonly found in soil, significantly altering the VSI and impacting the characterization of structural parameters. Nonetheless, these micropores are often overlooked in relevant analyses. Moreover, the characterization process relies on the utilization of theoretical models to fit the VSI. However, the commonly used models are not designed for VSI, raising concerns about their reliability. To investigate the influence of micropores on VSI and assess the reliability of various characterization models, this study used molecular simulation techniques to generate VSIs for kaolinite samples with different pore sizes. The simulation results reveal the effects of pore size on VSI shape, shed light on the influence of soil surfaces on pore water density and orientation, and highlight the important role of hydrogen bonds in water retention within the kaolinite pores. Furthermore, the reliability of three structural parameter characterization models, namely BET, DR, and as plot, was evaluated with the aid of the explicit geometric dimensions in molecular models, and the mechanisms responsible for their reliability were elucidated. This study deepens the understanding of VSI and provides crucial references for the characterization of soil structural parameters.

Electrospun Membranes Based on Quaternized Polysulfones: Rheological Properties-Electrospinning Mechanisms Relationship.

Composite membranes based on a polymer mixture solution of quaternized polysulfone (PSFQ), cellulose acetate phthalate (CAP), and polyvinylidene fluoride (PVDF) for biomedical applications were successfully obtained through the electrospinning technique. To ensure the polysulfone membranes' functionality in targeted applications, the selection of electrospinning conditions was essential. Moreover, understanding the geometric characteristics and morphology of fibrous membranes is crucial in designing them to meet the performance standards necessary for future biomedical applications. Thus, the viscosity of the solutions used in the electrospinning process was determined, and the morphology of the electrospun membranes was examined using scanning electron microscopy (SEM). Investigations on the surfaces of electrospun membranes based on water vapor sorption data have demonstrated that their surface properties dictate their biological ability more than their specific surfaces. Furthermore, in order to understand the different macromolecular rearrangements of membrane structures caused by physical interactions between the polymeric chains as well as by the orientation of functional groups during the electrospinning process, Fourier transform infrared (FTIR) spectroscopy was used. The applicability of composite membranes in the biomedical field was established by bacterial adhesion testing on the surface of electrospun membranes using Escherichia coli and Staphylococcus aureus microorganisms. The biological experiments conducted establish a foundation for future applications of these membranes and validate their effectiveness in specific fields.

Colyophilized Sugar-Polymer Dispersions for Enhanced Processing and Storage Stability.

Sucrose and trehalose pharmaceutical excipients are employed to stabilize protein therapeutics in a dried state. The mechanism of therapeutic protein stabilization is dependent on the sugars being present in an amorphous solid-state. Colyophilization of sugars with high glass transition polymers, polyvinylpyrrolidone (PVP), and poly(vinylpyrrolidone vinyl acetate) (PVPVA), enhances amorphous sugar stability. This study investigates the stability of colyophilized sugar-polymer systems in the frozen solution state, dried state postlyophilization, and upon exposure to elevated humidity. Binary systems of sucrose or trehalose with PVP or PVPVA were lyophilized with sugar/polymer ratios ranging from 2:8 to 8:2. Frozen sugar-PVPVA solutions exhibited a higher glass transition temperature of the maximally freeze-concentrated amorphous phase (Tg') compared to sugar-PVP solutions, despite the glass transition temperature (Tg) of PVPVA being lower than PVP. Tg values of all colyophilized systems were in a similar temperature range irrespective of polymer type. Greater hydrogen bonding between sugars and PVP and the lower hygroscopicity of PVPVA influenced polymer antiplasticization effects and the plasticization effects of residual water. Plasticization due to water sorption was investigated in a dynamic vapor sorption humidity ramping experiment. Lyophilized sucrose systems exhibited increased amorphous stability compared to trehalose upon exposure to the humidity. Recrystallization of trehalose was observed and stabilized by polymer addition. Lower concentrations of PVP inhibited trehalose recrystallization compared to PVPVA. These stabilizing effects were attributed to the increased hydrogen bonding between trehalose and PVP compared to trehalose and PVPVA. Overall, the study demonstrated how differences in polymer hygroscopicity and hydrogen bonding with sugars influence the stability of colyophilized amorphous dispersions. These insights into excipient solid-state stability are relevant to the development of stabilized biopharmaceutical solid-state formulations.

Hydric Environment and Chemical Composition Shape Non-avian Reptile Eggshell Absorption.

The amniotic egg fulfils a critical role in reproduction by serving as an interface between the external environment and the embryo. Because non-avian reptiles are rarely incubated, they must be heated by, and absorb water from, the oviposition site for the developing embryo. The mechanisms by which they absorb sufficient, but not excess, water and how these mechanisms vary with local habitat is largely unknown, despite its significance to their evolution. Here, we first performed histology, Fourier-transform infrared spectroscopy and dynamic vapor sorption experiments to elucidate the mechanisms of eggshell absorption for 56 reptile species. Then, we used phylogenetic comparative analysis to test the hypothesis that the absorptive capacity of reptile eggshells increases with aridity of the environment. We found that water absorption increases in the presence of a superficial mucopolysaccharide layer and decreases with increased calcium content. We found that eggs from arid environments have highly absorbent eggshells, but only in species with weakly calcified shells. Our results suggest that reptile eggshells have over evolutionary time tuned absorptive capacity to environmental moisture level. Since these eggs often must sustain conflicting constraints, they may serve as inspirations for new biomimetic materials, such as water filtering membranes or humidity sensors.

THE METHODS OF THE SORBED QUANTITY OF THE DIFFUSION COEFFICIENTS AND POLYMERS LIQUID AREAS

Has been discussed diffusion coefficients, the amount of the liquid particles sorbed by quantity, as well as the methods of determining molecular masses of polymers. We were researching liquid area’s kinetics of vapor sorption on the MCBean scale. We’ll also determine the molecular masses of polymers by the viscozimetric method.

Investigation on sacrificial hydrolysis reaction of octadecyltrimethoxysilane for moisture resistance enhancement of metal–organic framework

Imparting water resistance is important for structures which is vulnerable to moisture to maintain the performance. In this study, octadecyltrimethoxysilane (ODTMS), which forms a hydrophobic surface through polymerization on the surface of the material, was used to enhance the hydrophobicity of HKUST-1 (HHK-x). This self-assembled structure reacts as sacrificial barrier to continuously penetrating H2O molecules and this effect is evaluated with detection of O–H peak (3323 cm−1) in FT-IR spectra. The gas adsorption performance is conducted with CO2 gas and the adsorption amount was reduced by 20 % (from 5.77 to 4.62 mmol/g at 25 °C, 1 bar) compared with the pristine HKUST-1 following the trend of specific surface area. However, water adsorption amount was reduced by 50.2 %, which is 2.5 times higher than the decrease in CO2 adsorption capacity. In addition, when the N2 adsorption and cycle adsorption performances were compared after exposing the sample to air for five days, it was confirmed that HHK-40 maintained its microporous structure and stable performance. The manufactured materials exhibited higher durability in a cyclic vapor sorption test depending on the loading amount of ODTMS and exhibits different tendency depending on the rate of humidity. These results experimentally indicate that accessible self-assembly process of ODTMS on water-vulnerable materials to be sustainable and stable in humid air conditions.

Avoiding pitfalls in molecular simulation of vapor sorption: Example of propane and isobutane in metal-organic frameworks for adsorption cooling applications.

This study introduces recommendations for conducting molecular simulations of vapor adsorption, with an emphasis on enhancing the accuracy, reproducibility, and comparability of results. The first aspect we address is consistency in the implementation of some details of typical molecular models, including tail corrections and cutoff distances, due to their significant influence on generated data. We highlight the importance of explicitly calculating the saturation pressures at relevant temperatures using methods such as Gibbs ensemble Monte Carlo simulations and illustrate some pitfalls in extrapolating saturation pressures using this method. For grand canonical Monte Carlo (GCMC) simulations, the input fugacity is usually calculated using an equation of state, which often requires the critical parameters of the fluid. We show the importance of using critical parameters derived from the simulation with the same model to ensure internal consistency between the simulated explicit adsorbate phase and the implicit bulk phase in GCMC. We show the advantages of presenting isotherms on a relative pressure scale to facilitate easier comparison among models and with experiment. Extending these guidelines to a practical case study, we evaluate the performance of various isoreticular metal-organic frameworks (MOFs) in adsorption cooling applications. This includes examining the advantages of using propane and isobutane as working fluids and identifying MOFs with a superior performance.

Highly permeable membrane based on permax and PEG for air dehumidification

In this work, polyethylene glycol (PEG) with varying molecular weights was incorporated into the water-based polyurethane matrix (Permax232) to prepare Permax/PEG blend membranes for air dehumidification. The physical properties of the prepared membranes were characterized by FTIR, SEM, XRD and DSC. Furthermore, the influence of PEG molecular weight on the water vapor adsorption and permeability properties of the Permax/PEG blend membranes was investigated. The experimental results showed that blending PEG600 into the Permax232 matrix obtained optimal performance for air dehumidification. The water vapor sorption enthalpy and the permeation activation energy in the membranes were determined. Furthermore, Permax/20PEG600/PAN thin film composite membrane was developed via dip-coating method. The composite membrane showed superior water vapor permeance of 6578 GPU and water vapor/N2 selectivity of 4909 and a satisfactory long-term stability, which had potential industrial application for energy efficient dehumidification.

A drug–drug cocrystal strategy to regulate stability and solubility: A case study of temozolomide/caffeic acid

Temozolomide (TMZ) is a common clinical drug widely used to treat glioblastoma multiforme and gradual astrocytoma. Despite its widespread use in cancer treatment, issues remain with the solubility and stability of TMZ, which can be addressed by synthesizing novel pharmaceutical cocrystals. This study sought to enhance the physiochemical properties of TMZ. To this end, a pioneering pharmaceutical cocrystal of TMZ and caffeic acid (CAF), 2TMZ–CAF·0·5H2O (2:1:0.5) was synthesized and characterized using a solution method. The cocrystal structure was analyzed by molecular surface electrostatic potential (MESP), Hirshfeld surface analysis, and 2D fingerprinting. They were further characterized by single crystal X-ray diffraction, power X-ray diffraction, proton nuclear magnetic resonance, thermogravimetry-differential scanning calorimetry, dynamic vapor sorption, and Fourier transform infrared spectroscopy. Furthermore, the hygroscopicity, stability, and solubility of the TMZ–CAF cocrystal were investigated to evaluate their pharmaceutical applicability. In the asymmetric unit of the novel synthesized cocrystal, two complementary molecules of TMZ and CAF were found, forming planar hydrogen bonding pairs such as O–H···O, N–H···O, and O–H···N. Moreover, the cocrystals exhibited excellent stability compared to TMZ alone and regulated solubility during accelerated stabilization and dissolution processes. Hence, the cocrystals boast characteristics that can circumvent the rapid release of TMZ. In conclusion, the newly synthesized 2TMZ–CAF·0·5H2O cocrystals demonstrate enhanced physiochemical properties, including improved stability and solubility, compared to pure TMZ. This suggests potential utility in drug delivery systems. Additionally, the findings underscore the growing importance of pharmaceutical cocrystals in drug development, with implications for advancing cancer treatment and drug formulation strategies.

New Cocrystals of Ligustrazine: Enhancing Hygroscopicity and Stability.

Ligustrazine (TMP) is the main active ingredient extracted from Rhizoma Chuanxiong, which is used in the treatment of cardiovascular and cerebrovascular diseases, with the drawback of being unstable and readily sublimated. Cocrystal technology is an effective method to improve the stability of TMP. Three benzoic acid compounds including P-aminobenzoic acid (PABA), 3-Aminobenzoic acid (MABA), and 3,5-Dinitrobenzoic acid (DNBA) were chosen for co-crystallization with TMP. Three novel cocrystals were obtained, including TMP-PABA (1:2), TMP-MABA (1.5:1), and TMP-DNBA (0.5:1). Hygroscopicity was characterized by the dynamic vapor sorption (DVS) method. Three cocrystals significantly improved the hygroscopicity stability, and the mass change in TMP decreased from 25% to 1.64% (TMP-PABA), 0.12% (TMP-MABA), and 0.03% (TMP-DNBA) at 90% relative humidity. The melting points of the three cocrystals were all higher than TMP, among which the TMP-DNBA cocrystal had the highest melting point and showed the best stability in reducing hygroscopicity. Crystal structure analysis shows that the mesh-like structure formed by the O-H⋯N hydrogen bond in the TMP-DNBA cocrystal was the reason for improving the stability of TMP.

Measurement of Water Uptake and States in Nafion Membranes Using Humidity-Controlled Terahertz Time-Domain Spectroscopy.

Perfluorinated sulfonic acid ionomers are well known for their unique water uptake properties and chemical/mechanical stability. Understanding their performance-stability trade-offs is key to realizing membranes with optimal properties. Terahertz time-domain spectroscopy has been demonstrated to resolve water states inside industrially relevant membranes, producing qualitatively agreeable results to conventional gravimetric analysis and prior demonstrations. Using the proposed humidity-controlled terahertz time-domain spectroscopy, here we quantify this detailed water information inside commercially available Nafion membranes at various humidities for direct comparison against literature values from dynamic vapor sorption, differential scanning calorimetry, and Fourier transform infrared spectroscopy on selected samples. Using this technique therefore opens up opportunities for rapid future parameter space investigation for membrane optimization.