Mechanism Of Water Adsorption Research Articles

Understanding water adsorption in hierarchical carbon — The significance of pore connectivity and functional group configurations

Hierarchical carbon has drawn considerable attention due to its high capacity and fast kinetics in gas separation and purification in the fuel industry. The presence of water in most applications poses a challenge; hence, understanding how water interferes with the removal of undesired substances in the micro-mesoporous structure of the hierarchical carbon is required to assess and manage its impacts. Monte Carlo simulation was conducted in this paper to investigate water adsorption in a serially connected micro and mesopore model that mimics the hierarchical carbon. Our results reveal the critical role of pore connectivity, the topology of the junction between micropore and mesopore, and functional groups. Notably, the junction facilitates the formation of water clusters having a convex interface at the junction, followed by their coalescence with the localized clusters in the mesopore to form a liquid-like condensate with the concave interface. It is this transition from clusters with a convex interface to condensate with the concave interface that is the prerequisite for mesopore filling. Temperature has an opposing effect in the filling of micropores and mesopores; for the former, the onset of filling occurs at higher reduced pressure as the temperature is increased, while the opposite is true for mesopores. Our simulation results provide significant insights into the mechanism of water adsorption, which paves the path for utilizing hierarchical carbon in removing harmful substances from water-laden feed streams.

Modeling of multilayer water adsorption and condensation in slits of cement minerals by molecule simulation and adsorption isotherm

The interactions between water and multiscale pores affect significantly most of the physical and chemical properties of cementitious materials such as cement mortar, paste, and concrete. In this paper, molecular mechanism of multilayer water adsorption and condensation in micropores of typical cementitious minerals, the dicalcium silicate (C2S) and calcium silicate hydrate (C-S-H), were investigated by molecular simulations. Classical adsorption isotherm models were examined for their applicability to describe the adsorption law in molecular scales. Besides, the Kelvin equation was modified to satisfy the description of condensation at the microscale. Calculation results show that the most commonly used Brunauer-Emmett-Teller (BET) model can only describe the isotherms within a limited range of low water vapor pressures. In comparison, the modified Brunauer-Emmett-Teller-Pickett (BETP) model can describe the adsorption of water molecular on the surface of C2S and C-S-H more precisely, due to considering the adsorption layers as finite at saturation pressure and the reduced escape probability of the outermost layer of adsorbed water molecules. As for the condensation of water molecules in C2S and C-S-H slits, the traditional Kelvin equation is not applicable. Therefore, a refined Kelvin equation was proposed to describe the relationship between pore size and the pressure required for condensation accurately by considering the critical pore size, adsorption thickness, and decay rate of adsorption potential energy. Further analysis suggests that C2S releases more first-layer adsorption heat and thus shows stronger adsorption of water molecules compared to C-S-H.

Monitoring water harvesting in metal-organic frameworks, one water molecule at a time.

Metal-organic frameworks (MOFs) have gained prominence as potential materials for atmospheric water harvesting, a vital solution for arid regions and areas experiencing severe water shortages. However, the molecular factors influencing the performance of MOFs in capturing water from the air remain elusive. Among all MOFs, Ni2X2BTDD (X = F, Cl, Br) stands out as a promising water harvester due to its ability to adsorb substantial amounts of water at low relative humidity (RH). Here, we use advanced molecular dynamics simulations carried out with the state-of-the-art MB-pol data-driven many-body potential to monitor water adsorption in the three Ni2X2BTDD variants as a function of RH. Our simulations reveal that the type of halide atom in the three Ni2X2BTDD frameworks significantly influences the corresponding molecular mechanisms of water adsorption: while water molecules form strong hydrogen bonds with the fluoride atoms in Ni2F2BTDD, they tend to form hydrogen bonds with the nitrogen atoms of the triazolate linkers in Ni2Cl2BTDD and Ni2Br2BTDD. Importantly, the large size of the bromide atoms reduces the void volume in the Ni2Br2BTDD pores, which enable water molecules to initiate an extended hydrogen-bond network at lower RH. These findings not only underscore the prospect for precisely tuning structural and chemical modifications of the frameworks to optimize their interaction with water, but also highlight the predictive power of simulations with the MB-pol data-driven many-body potential. By providing a realistic description of water under different thermodynamic conditions and environments, these simulations yield unique, molecular-level insights that can guide the design and optimization of energy-efficient water harvesting materials.

Molecular and Dissociative Adsorption of H2O on ZrO2/YSZ Surfaces

The work involves first-principles calculations to study the mechanism of adsorption of water molecules on the surface of ZrO2 and their yttrium-stabilized structures (YSZ). Calculations of the electronic properties of ZrO2 showed that during the m-t phase transformation of ZrO2, the Fermi level first shifts by 0.125 eV towards the conduction band, and then in the t-c region goes down by 0.08 eV. In this case, the band gaps for c-ZrO2, t-ZrO2 and m-ZrO2, respectively, are 5.140 eV, 5.898 eV and 5.288 eV. Calculations to determine the surface energy showed that t-ZrO2 (101) and m-ZrO2 (111) have the most stable structure, on the basis of which it was first discovered that the surface energy is somehow inversely related to the value of the band gap, since as the band gap increases, the surface energy tends to decrease. An analysis of the mechanism of water adsorption on the surface of t-ZrO2 (101) and t-YSZ (101) showed that H2O on unstabilized t-ZrO2 (101) is adsorbed dissociatively with an energy of −1.22 eV, as well as by the method of molecular chemisorption with an energy of −0.69 eV and the formation of a hydrogen bond with a bond length of 1.01 Å. In the case of t-YSZ (101), water is molecularly adsorbed onto the surface with an energy of −1.84 eV. Dissociative adsorption of water occurs at an energy of −1.23 eV, near the yttrium atom. The obtained results complement the database of research works carried out in the field of the application of biocompatible zirconium dioxide crystals and ceramics in green energy generation, and can be used in designing humidity-to-electricity converters and in creating solid oxide fuel cells based on ZrO2.

A Detailed Comparative Analysis of the Structural Stability and Electron-Phonon Properties of ZrO2: Mechanisms of Water Adsorption on t-ZrO2 (101) and t-YSZ (101) Surfaces.

In this study, we considered the structural stability, electronic properties, and phonon dispersion of the cubic (c-ZrO2), tetragonal (t-ZrO2), and monoclinic (m-ZrO2) phases of ZrO2. We found that the monoclinic phase of zirconium dioxide is the most stable among the three phases in terms of total energy, lowest enthalpy, highest entropy, and other thermodynamic properties. The smallest negative modes were found for m-ZrO2. Our analysis of the electronic properties showed that during the m-t phase transformation of ZrO2, the Fermi level first shifts by 0.125 eV toward higher energies, and then decreases by 0.08 eV in the t-c cross-section. The band gaps for c-ZrO2, t-ZrO2, and m-ZrO2 are 5.140 eV, 5.898 eV, and 5.288 eV, respectively. Calculations based on the analysis of the influence of doping 3.23, 6.67, 10.35, and 16.15 mol. %Y2O3 onto the m-ZrO2 structure showed that the enthalpy of m-YSZ decreases linearly, which accompanies the further stabilization of monoclinic ZrO2 and an increase in its defectiveness. A doping-induced and concentration-dependent phase transition in ZrO2 under the influence of Y2O3 was discovered, due to which the position of the Fermi level changes and the energy gap decreases. It has been established that the main contribution to the formation of the conduction band is made by the p-states of electrons, not only for pure systems, but also those doped with Y2O3. The t-ZrO2 (101) and t-YSZ (101) surface models were selected as optimal surfaces for water adsorption based on a comparison of their surface energies. An analysis of the mechanism of water adsorption on the surface of t-ZrO2 (101) and t-YSZ (101) showed that H2O on unstabilized t-ZrO2 (101) is adsorbed dissociatively with an energy of -1.22 eV, as well as by the method of molecular chemisorption with an energy of -0.69 eV and the formation of a hydrogen bond with a bond length of 1.01 Å. In the case of t-YSZ (101), water is molecularly adsorbed onto the surface with an energy of -1.84 eV. Dissociative adsorption of water occurs at an energy of -1.23 eV, near the yttrium atom. The results show that ab initio approaches are able to describe the mechanism of doping-induced phase transitions in (ZrO2+Y2O3)-like systems, based on which it can be assumed that DFT calculations can also flawlessly evaluate other physical and chemical properties of YSZ, which have not yet been studied quantum chemical research. The obtained results complement the database of research works carried out in the field of the application of biocompatible zirconium dioxide crystals and ceramics in green energy generation, and can be used in designing humidity-to-electricity converters and in creating solid oxide fuel cells based on ZrO2.

Water-Aluminum Interaction as Driving Force of Linde Type A Aluminophosphate Hydration.

Linde type A (LTA) aluminophosphate is a promising candidate for an energy storage material used for low-temperature solar and waste-heat management. The mechanism of reversible water adsorption, which is the basis for potential industrial applications, is still not clear. In this paper, we provide mechanistic insight into various aspects of the hydration process using molecular modeling methods. Building on accurate DFT calculations and available experimental data, we first refine the existing empirical force-field used in subsequent classical molecular dynamics simulations that captures the relevant physics of the water binding process. We succeed in fully reproducing the experimentally determined X-ray structure factors and use them to estimate the number of water molecules present in the fully hydrated state of the material. Furthermore, we show that the translational and orientational mobility of the confined water is significantly reduced and resembles the dynamics of glassy systems.

Metal-Organic Frameworks for Water Harvesting and Concurrent Carbon Capture: A Review for Hygroscopic Materials.

As water scarcity becomes a pending global issue, hygroscopic materials prove a significant solution. Thus, there is a good cause following the structure-performance relationship to review the recent development of hygroscopic materialsand provide inspirational insight intocreative materials. Herein, traditional hygroscopic materials, crystalline frameworks,polymers, and composite materials are reviewed. The similarity in working conditions of water harvesting and carbon capture makes simultaneously addressing water shortages and reduction of greenhouse effects possible. Concurrent water harvesting and carbon capture islikely to become a future challenge. Therefore, an emphasis is laid on metal-organic frameworks (MOFs) for their excellent performance in water and CO2adsorption, and representative role of micro- and mesoporous materials. Herein, the water adsorption mechanisms of MOFs are summarized, followed by a review of MOF's water stability, with a highlight on the emerging machine learning (ML) technique to predict MOF water stability and water uptake. Recent advances in the mechanistic elaboration of moisture's effects on CO2adsorption are reviewed.This review summarizes recent advances in water-harvesting porous materials with special attention on MOFs and expects to direct researchers' attention into the topic of concurrent water harvesting and carbon capture as a future challenge.

Experimental and molecular investigation of water adsorption controls in marine and lacustrine shale reservoirs

The restriction of hydrocarbon migration within shale reservoirs by pre-adsorbed water necessitates an investigation into water adsorption control mechanisms within shales. In this study, water vapor adsorption isotherms obtained from marine and lacustrine shale samples along with isotherms from their organic matter and experimentally verified kerogen molecular models were used to evaluate water adsorption mechanisms, with simulated wet kerogen-quartz nanocomposites. Furthermore, these were also used to investigate organic matter-inorganic interaction controls on water adsorption. Pore size distribution (PSD) controls on water distribution in organic matter were obtained via water vapor adsorption and low-pressure nitrogen adsorption analysis, along with small angle neutron scattering (SANS) analysis. The results reveal water adsorption is linked to changes in mesopore volume within organic matter and porosity in kerogen models. PSD obtained from the shales only reveal mesopore controls at high RH, with water adsorption mainly controlled by oxygen functional groups in organic matter pores and swelling clays. Inorganic controls on water adsorption are also observed in adsorbed water not tightly bound to the shale surface due to a high montmorillonite content in clay interlayers, and organic matter interaction with quartz with a negative relationship between the adsorbed water and the quartz content. Collectively, these findings indicate that CO2 migration in shale reservoirs could be inhibited by water that is distributed in potential CO2 adsorption sites within organic matter pores and montmorillonite.

Structure and thermodynamics of water adsorption in NU-1500-Cr

Metal-organic frameworks (MOFs) are a class of materials with diverse chemical and structural properties, and have been shown to effectively adsorb various types of guest molecules. The mechanism of water adsorption in NU-1500-Cr, a high-performance atmospheric water harvesting MOF, is investigated using a combination of molecular dynamics simulations and infrared spectroscopy. Calculations of thermodynamic and dynamical properties of water as a function of relative humidity allow for following the adsorption process from the initial hydration stage to complete filling of the MOF pores. Initial hydration begins at the water molecules that saturate the open Cr3+ sites of the framework, which is then followed by the formation of water chains that extend along the channels connecting the hexagonal pores of the framework. Water present in these channels gradually coalesces and fills the hexagonal pores sequentially after the channels are completely hydrated. The development of hydrogen-bond networks inside the MOF pores as a function of relative humidity is characterized at the molecular level using experimental and computational infrared spectroscopy. A detailed analysis of the OH-stretch vibrational band indicates that the low-frequency tail stems from strongly polarized hydrogen-bonded water molecules, suggesting the presence of some structural disorder in the experimental samples. Strategies for designing efficient water harvesting MOFs are also proposed based on the mechanism of water adsorption in NU-1500-Cr.

Water adsorption properties of microalgae powders: Thermodynamic analysis and structural characteristics

Moisture adsorption isotherms and thermodynamic properties of dried Chlorella pyrenoidesa and Spirulina platensis powders were investigated by using a static gravimetric at temperatures of 20, 30, and 40 °C and within aw range of 0.112–0.976. Structural characteristics involving morphology, functional group, surface element composition, pore size distribution, and surface area were analyzed to explore the water adsorption mechanism. FTIR and XPS analysis indicated that spirulina powder had a higher proportion of hydrophilic sites to bind water molecules in comparison with chlorella powder. BET surface area for chlorella and spirulina powders were 25.10 and 25.19 m2/g, respectively. Water adsorption data were adjusted using a variety of sorption models, and the GAB equation was the most appropriate for representing the experimental data in the studied aw and temperature range. The monolayer moisture content (Xm) values at 20, 30 and 40 °C were 0.0526, 0.0483, and 0.0456 g/g dry basis for chlorella powders, and 0.0581, 0.0553, and 0.0420 g/g dry basis for spirulina powders, respectively. The net isosteric heat (Qst) and differential entropy (δSdif) for both microalgae powders decreased with an increase in water content. Using the compensation theory, we determined that the processes were governed by the enthalpy and that they were non-spontaneous (δG>0) for the samples. Both microalgae powers were classified as micro and mesoporous materials, and the pore radius (Rp) varied from 1.481 to 23.694 nm for chlorella powders and from 1.193 to 39.392 nm for spirulina powders, respectively.

Experimental and Numerical Research on Water Transport during Adsorption and Desorption in Cement-Based Materials

The durability of cement-based materials is related to water transport and storage in their pore network under different humidity conditions. To understand the mechanism and characteristics of water adsorption and desorption processes from the microscopic scale, this study introduces different points of view for the pore space model generation and numerical simulation of water transport by considering the “ink-bottle” effect. On the basis of the pore structure parameters (i.e., pore size distribution and porosity) of cement paste and mortar with water-binder ratios of 0.3, 0.4 and 0.5 obtained via mercury intrusion porosimetry, randomly formed 3D pore space models are generated using two-phase transformation on Gaussian random fields and verified via image analysis method of mathematical morphology. Considering the Kelvin-Laplace equation and the influence of “ink-bottle” pores, two numerical calculation scenarios based on mathematical morphology are proposed and applied to the generated model to simulate the adsorption-desorption process. The simulated adsorption and desorption curves are close to those of the experiment, verifying the effectiveness of the developed model and methods. The obtained results characterize water transport in cement-based materials during the variation of relative humidity and further explain the hysteresis effect due to “ink-bottle” pores from the microscopic scale.

Determination of water adsorption mechanisms in NH4ZSM-5 and НZSM-5 zeolites

This article covers the results of a study on the determination of the differential heat, isotherm and entropy of water vapor in ZSM-5 zeolites at a temperature of 303 K using the adsorption-calorimetric method. The type and number of ion-molecular formed complexes, as well as the mechanism of adsorption of the studied molecules, were determined. By studying their energetic properties, it is possible to determine the chemical composition and crystal structures of the zeolites. The adsorption isotherm was described by two-and three-had mathematical equations of the TVSM (the theory of volumetric saturation of microgroups) from the beginning to saturation. An analysis of the obtained results proved that NH4ZSM-5 and NZSM-5, which are used as catalysts, can be used as zeolites.

Effect of oxygen functional groups on competitive adsorption of benzene and water on carbon materials: Density functional theory study

It is important to study the effect of oxygen-containing functional groups on the competitive adsorption mechanism of benzene and water on the surface of carbon materials, and to directional modification of activated carbon to improve its selective adsorption of benzene in air. In this study, the adsorption characteristics of benzene and water on original and linked ester, carboxyl, hydroxyl, carbon materials linked by ether groups were calculated by quantum chemical simulation based on density functional theory. The types and proportions of weak interactions in the adsorption process were calculated by energy decomposition analysis, and the adsorption mechanism of carbon materials for water and benzene was described. The influence and contribution of oxygen-containing functional groups on the adsorption of benzene and water were further analyzed by van der Waals potential and electrostatic potential, respectively, so as to determine the difference in the adsorption effect of different types of oxygen-containing functional groups on the two molecules. It was found that the carboxyl group has a great influence on the hydrophilicity of carbon materials, and the electrostatic potential distribution before and after linking the carboxyl group changed significantly. Therefore, they can attract each other with water through hydrogen bonds and occupy the surface adsorption sites of carbon materials, thereby inhibiting the adsorption of benzene on carbon materials. On the contrary, due to its hydrophobic properties, the ether group will free up adsorption space for the adsorption of benzene on the surface of the carbon material, which is beneficial to the adsorption of benzene. The adsorption experiments were carried out, and the results were consistent with the simulation. This study provides an idea for preparing efficient carbonaceous adsorbent of benzene and reducing benzene pollution in industry.

Performance evaluation of silicoaluminophosphate with SFO topology for water-sorption-driven heating and cooling systems

Low-grade thermal-driven water-based sorption chillers and heat pumps are promising strategies to realize the near-zero-carbon target. However, developing excellent-performance water-sorption materials driven by ultralow-temperature thermal energy is still a key issue. In this study, silicoaluminophosphate with SFO topology (SAPO-SFO) synthesized by hydrothermal method is proposed as a more-effective adsorbent for water-based sorption applications. SAPO-SFO exhibits large micropore volume of 0.22–0.28 ml g−1, high water uptake of 0.24–0.28 g g−1 at P/P0 = 0.2, low regeneration temperature, and excellent hydrothermal stability. Importantly, the water-based sorption applications employing SAPO-SFO with 7 wt% Si achieve extremely high coefficients of performance of 0.86 for cooling and 1.76 for heating at low-driven temperatures of 64 °C and 82 °C, respectively. Furthermore, the mechanism of water adsorption for SAPO-SFO is revealed as that large purely siliceous regions and defects induced by uneven silicon insertion result in low enthalpy of adsorption. These results make SAPO-SFO a potential high-performance and ultralow-temperature thermal driven porous material for water-based sorption applications.

The new multistage water adsorption model of Longmaxi Formation shale considering the spatial configuration relationship between organic matter and clay minerals

The water adsorption by shale significantly affects shale gas content and its seepage capacity. However, the mechanism of water adsorption by shale is still unclear due to its strong heterogeneity and complicated pore structure. The relationship between the adsorbed water content at different relative humidities (RHs) and shale compositions, as well as shale pore structure and the spatial configuration relationship between organic matter (OM) and clay minerals, was investigated to clarify the controlling factors and mechanisms of water adsorption by Longmaxi Formation shale from the Southern Sichuan Basin in China. Consequently, the water adsorption process could be generally divided into three different stages from 0%RH to 99%RH. Furthermore, the Johnston's clay mineral interlayer pore structure model (JCM), the Freundlich model (FM) and the Dubinin–Astakhov model (DAM) were tested to fit the three water adsorption stages from low RH to high RH, respectively. The fitting results of the JCM and FM at lower RHs were far from good, while the fitting results of DAM at higher RHs were acceptable. Accordingly, two revised models (LRHM and MRHM) considering the spatial configuration relationship between OM and clay minerals were proposed for the two stages with lower RHs, and performed better fitting results indicating the pronounced effect of the spatial configuration relationship between OM and clay minerals on the water adsorption process of Longmaxi Formation shale. The outcomes of this study will contribute to clarifying the water distribution characteristics in the pore network of shale samples with variable water contents.

A modified Guggenheim-Anderson-Boer model for analyzing water sorption in coal

The presence of water can alter the mechanical properties of coal, which may not only cause roof falls during the coal mining process but also affect the hydraulic fracturing of coalbed methane (CBM) reservoirs. The nature of water adsorption properties in unconventional reservoir rocks has been the subject of several recent papers. However, the adsorption properties and adsorption mechanism of water in coal have not been thoroughly investigated. In this study, we carried out water vapor sorption experiments on four coal samples of different maturities. We found no linear relationship between maturity and water adsorption capacity. Furthermore, we proposed that the water adsorption mechanism in coal can be divided into two types: attached to oxygen functional groups and pore filling, which occur in hydrophilic pores and hydrophobic pores, respectively. Based on the above hypothesis, a modified Guggenheim-Anderson-Boer model was proposed to interpret water adsorption isotherms. It was concluded that the differences in the water adsorption characteristics of different coals under high humidity conditions were caused by the pore volume and the proportion of hydrophilic pores. We further analyzed the influence mechanism of water adsorption on methane adsorption under high relative humidity conditions. We found that the influence of water adsorption on methane adsorption in coal can be attributed to the water adsorption amount and proportion of hydrophilic pores.

Grand canonical Monte Carlo simulation study on the effect of crystallinity and structural disorder on water sorption in geopolymers

A comparative study on water sorption by different components of the binder phase formed in geopolymerization was performed using the Grand Canonical Monte Carlo (GCMC) simulation method. Water sorption isotherms for crystalline, defective and amorphous model structures with Na+ exchangeable cations at temperatures of 298 K were obtained. The isosteric heats of adsorption of water in each structure were calculated. In addition, the distribution pattern of H2O molecules in the researched frameworks and the preferred sorption sites were also investigated. The GCMC results showed that the structural changes in the host framework significantly affect water sorption properties, leading to changes in water sorption capacity and nature of interactions with guest water molecules. The GCMC simulation results have provided useful information on the behavior of water confined in geopolymeric binder phase, which is difficult to observe experimentally, contributing to a better understanding of the mechanism of water adsorption in geopolymer-zeolite hybrid materials.

QCM Measurements of RH with Nanostructured Carbon-Based Materials: Part 1—Theory and Model

In this series of two papers, the humidity sensing of a carbon nanotube’s (CNTs) network-based material is studied through quartz crystal microbalance (QCM) sensors. To this aim, quartzes functionalized with different amounts of sensing material were realized, exposed to different humidity levels, and characterized. In this first paper, the theoretical framework is presented, whereas the second one presents the experimental study. This paper discusses at first the water adsorption and desorption on single-wall carbon nanotube (SWCNT) networks, and subsequently deeply investigates the behavior of QCM-based measurements. Numerical simulations based on the equivalent electrical model of the quartz were used for predicting the vibrational behavior of functionalized QCMs when exposed to different humidity levels, accounting for the effect of the different water adsorption mechanisms: chemisorption, physisorption, and capillary condensation.

Insights into the adsorption mechanism of water at different coverage rates on talc (Mg3Si4O10(OH)2) (0 0 1) basal surface: A first-principles study

Study on the interaction between water and mineral surface is significant for the understanding of the subsequent interfacial reactions during the flotation. In this work, the adsorption of water at different coverage rates on talc (001) basal surface was creatively researched by first-principles calculations. We found the single water adsorption on talc (001) basal surface was majorly through the H-bond between surface Os and water Hw and H-bond between surface Hs and water Ow with the adsorption energy ranges from −24.26 kJ/mol to −3.8 kJ/mol, and the bonding mechanism of H-bond was attributed to the orbital hybridization of H atom and O atom. Furthermore, we found more H-bonds were formed on talc surface with the increasing water coverage rates, and the average adsorption energy of water was gradually decreased. Thus, the adsorption of water on talc (001) basal surface was enhanced with the increasing water coverage rates, and the talc surface became more stable after water adsorption. Moreover, charge transfers from water to the talc surfaces occurred, and the work function of talc surfaces gradually decreased when the coverage rates of water were low while increased when the coverage rates of water were higher.

A new dynamic imbibition model for penny-shaped blind pores in shale gas well

Penny-shaped blind pores are common in shale, these pores with the original gas occurrence, including free gas and adsorbed gas, are seriously affected by a large amount of imbibed fracturing fluid. The competitive gas–water adsorption mechanism and the equations of gas-water phase pressures were analyzed statistically to detail the changes in gas–water distribution during imbibition. Based on the Lucas–Washburn equation, a new dynamic imbibition model is established for penny-shaped blind pores in shale gas reservoirs, which first considers the resistance of desorption of adsorbed gas and free gas and the factors of pore shape and fractal characteristics. The experimental validation, dimensionless-type curve, and common features of the new model regarding water imbibition are analyzed in detail. The results indicated that the proposed model is suitable for accurately predicting the imbibition in blind pores, and the dimensionless-type curve can simplify the calculation process for imbibition predictions. Factor analysis showed that penny-shaped pore width and length are two important factors for imbibition, the smaller width and the longer length, the more imbibition. Meanwhile, the increase of gas-water interfacial tension and displacement pressure is conducive to imbibition, the increase of initial gas pressure and desorption of adsorbed gas is obstructive to imbibition. The research is not only applicable in shale gas reservoir but also useful for geological hydrogen storage, carbon dioxide storage and geothermal development.