Swelling Effect Research Articles

Pore network modelling of CO2-shale interaction for carbon storage: Swelling effect and fracture permeability

Pore network modelling of CO2-shale interaction for carbon storage: Swelling effect and fracture permeability

Enhanced water‐induced shape memory and swelling characteristics of graphene oxide‐cellulose nanofiber reinforced polyvinyl alcohol nanocomposites

AbstractAn efficient water‐induced shape memory polymer (SMP) has been developed by incorporating graphene oxide (GO) and cellulose nanofibers (CNF) into polyvinyl alcohol (PVA) matrix. The resulting PVA/GO‐CNF hybrid nanocomposite films at 1 wt% exhibit synergistic effect with superior water‐induced shape memory performance, with 100% shape recovery within 37 sec. Moreover, these hybrid nanocomposite films at 1 wt% demonstrate superior mechanical strength of 77.9 MPa and an improved glass transition temperature (Tg) of 61.4°C in dry conditions. The synergetic effect of GO and CNF in PVA overcomes the limitations of other PVA‐based SMPs in terms of mechanical properties, dimensional stability, and resistance to excessive swelling. Exposure to water significantly reduces Tg to 24.2°C, as confirmed by DSC analysis, which is attributed to the decrease in hydrogen bonding between PVA and 1 wt% GO‐CNF caused by the swelling and plasticizing effect of water. Consequently, the shape recovery of the PVA/1 wt% GO‐CNF occurs with a switching temperature activation due to the polymer chains' released strain energy. These findings suggest that these hybrid films hold the potential for expanding the applications of SMPs in biomedical and moisture‐responsive application such as soft robotics and smart textiles, where water serves as the primary stimulus.Highlights PVA/1 wt% GO‐CNF hybrid film demonstrates 100% shape recovery in 37 sec. Water immersed PVA/1 wt% GO‐CNF nanocomposites show a reduction in Tg to 24.2°C. PVA/1 wt% GO‐CNF nanocomposite shows superior mechanical strength in dry conditions. Shape memory behavior is due to reduction in hydrogen bonding and plasticizing effect.

Quasi-vertically asymmetric channels of graphene oxide membrane for ultrafast ion sieving

The high performance of two-dimensional (2D) channel membranes is generally achieved by preparing ultrathin or forming short channels with less tortuous transport through self-assembly of small flakes, demonstrating potential for highly efficient water desalination and purification, gas and ion separation, and organic solvent waste treatment. Here, we report the construction of vertical channels in graphene oxide (GO) membrane based on a substrate template with asymmetric pores. The membranes achieved water permeance of 2647 L m−2 h−1 bar−1 while still maintaining an ultrahigh rejection rate of 99.9% for heavy metal ions, which is superior to the state-of-the-art 2D membranes reported. Furthermore, the membranes exhibited excellent stability during long-term filtration experiments for at least 48 h, as well as resistance to ultrasonic treatment for over 100 minutes. The vertical channels possess very short pathway for almost direct water transport and a highly effective channel area, meanwhile the asymmetric porous template enhances the packing of the inserted GO nanosheets to avoid the swelling effect of membrane. Our work provides a simple way to fabricate vertical channels of 2D nanofiltration membranes with high water purification performance.

Optical time-lapse microscopy for rapid assessment of microbial quality in hygroscopic food samples.

In the food industry, time-to-result is crucial for faster release of products, minimising recalls, mitigation of microbial contamination problems and, ultimately, food safety. Carrageenan is isolated from red seaweed (Rhodophyta) and applied in various foods and beverages as a gelling, thickening, texturing, or stabilising agent due to its hygroscopic properties. Currently, the standard industry plate count method entails a one-hundred-fold dilution of the sample before mixing with molten agar for assessing the level of microbial contamination in carrageenan samples prior to business-to-business shipment. However, even at this dilution, carrageenan swells, forms clumps, clogs pipettes, and leaves thick gel structures, bubbles, and debris in agar plates causing microbial enumeration to be challenging and subject to human error. Here, we report, for the first time, the application of mini agar plates monitored by the automated time-lapse microscopy IntuGrow solution to assess the microbiological quality in the challenging food ingredient. Without dilution of the food sample, the carrageenan powder is scattered between two layers of Plate Count Agar to enumerate bacteria within 12-20h, while enumeration by traditional plate counts requires 72h. A DELAY algorithm for optical time-lapse microscopy was developed and added to IntuGrow analysis software to suppress the effects of swelling and enhance detection of the presence of growing microbial colonies by normalising the background using previous images. Time-lapse microscopy image-based monitoring made it possible to obtain results from carrageenan samples that could not be obtained by traditional plate counts due to swarming bacteria. Comparison between the two methods showed a nearly perfect Demings slope of 0.96, while an observed bias of -0.33 log CFU/g indicated that IntuGrow counts were lower than traditional plate counts. This is likely due to carrageenan artefacts being counted as colonies in the latter plates. The ability of IntuGrow to enumerate bacteria in challenging food ingredients such as carrageenan implies that the technology should be easy to apply for easy-to-dilute samples or non-hydrocolloid powders. Further testing in an industrial setting by different operators should be used to validate the reproducibility of the method.

Tough and Fast‐Responding Fe3+‐Coordinated Poly (Acrylic Acid ‐N‐Isopropyl Acrylamide) Shape Memory Hydrogels

AbstractHydrogels with programmable shape memory hold great promise for applications in soft robots, smart medical devices, etc., but the preparation of tough and fast‐responding shape memory hydrogels remains challenging. In this work, Poly (acrylic acid ‐N‐isopropyl acrylamide) (3:1)‐Fe3+ (P(AA‐NIPAM)(3:1)‐Fe3+) hydrogels are obtained by monomer copolymerization and ionic coordination, which exhibited tough mechanical properties with a maximum tensile strength of 2.48 ± 0.08 MPa and a maximum elongation of 338.5 ± 19.6%. The hydrogel also demonstrated a good shape memory effect, with the hydrogel curled into a spiral shape recovering to 71.1% ± 5.9% in 30 s under the swelling effect of water, and the convoluted structure recovering to 95% in 4 s. The shape memory hydrogels prepared based on this method will provide an important reference value for the development of higher performance shape memory hydrogels.

Swelling effect of microneedle in the skin drug delivery using Stephan condition: analytical and numerical study

Swelling effect of microneedle in the skin drug delivery using Stephan condition: analytical and numerical study

Evaluating clinical meaningfulness of anti-β-amyloid therapies amidst amyloid-related imaging abnormalities concern in Alzheimer's disease.

Alzheimer's disease is the most prevalent form of dementia in the elderly, which is clinically characterized by a gradual and progressive deterioration of cognitive functions. The central and early role of β-amyloid in the pathogenesis of Alzheimer's disease is supported by a plethora of studies including genetic analyses, biomarker research and genome-wide association studies in both familial (early-onset) and sporadic (late-onset) forms of Alzheimer's. Monoclonal antibodies directed against β-amyloid demonstrate slowing of the clinical deterioration of patients with early Alzheimer's disease. Aducanumab, lecanemab and donanemab clinical trials showed slowing of Alzheimer's disease progression on composite scores by 25-40% based on the measure used. Anti-β-amyloid antibodies can cause side effects of bleeding and swelling in the brain, called amyloid-related imaging abnormalities. Amyloid-related imaging abnormalities typically occur early in treatment and are often asymptomatic, and though in rare cases, they can lead to serious or life-threatening events. The aim of this review is to evaluate the clinical meaningfulness of anti-β-amyloid therapies amidst amyloid-related imaging abnormalities concern in Alzheimer's disease.

Physical and Mechanical Properties of Fly Ash-Bottom Ash Geopolymer Mixtures on Expansive Clay Soil Stabilization as a Subgrade Material

Abstract The presence of expansive clay causes roads to undergo damage such as wavy, cracked, and even potholes. This type of soil shows that the soil is prone to swelling and shrinking. A base soil handling method against the effects of swelling and shrinking is chemical soil stabilization such as mixing the soil with lime, cement or additional materials. In this study, the stabilization method used was the fly ash and bottom ash geopolymerization reaction. Fly ash and bottom ash is an effective alternative to replace cement. Fly ash and bottom ash with addition of alkali activators of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) can serve as a binder similar to cement. This study aimed to improve the physical property and mechanical property tests of the soil such as bearing capacity and swelling potential as a requirement for subgrade. All physical property test results revealed that using fly ash-bottom ash geopolymer paste can improve qualities such as specific gravity, Atterberg limit, and grain size to improve expansive clay soil. Likewise, the mechanical property test results showed that the subgrade stabilized with fly ash-bottom ash geopolymer can increase its strength to surpass the requirements for road subgrades.

Contact Force Increases During Radiofrequency Ablation: A Novel Catheter Assessment of Myocardial Response to Thermal Injury.

Contact force (CF) changes after onset of radiofrequency (RF) delivery are not well understood and often ascribed to catheter instability. This study sought to characterize CF changes during RF-based pulmonary vein (PV) isolation. Catheter-tip parameters including CF for all RF sessions were extracted from a novel catheter-mapping system from 6 patients undergoing PV isolation. Of a total 416 RF sessions, 241 demonstrated progressive increases in CF during RF delivery (group 1). Zero to 5 seconds of RF delivery demonstrated the greatest increase in CF, with no differences between right and left PV sites (2.2 ± 2.2 vs 1.9 ± 2.3 g, P=0.26). Subsequent 5-second intervals demonstrated greater increases for right vs left PV sites (eg, 1.2 ± 1.3 vs 0.5 ± 0.3 g, P=0.01 for 20 to 25 seconds). CF increment was greater for posterior vs anterior PV sites (3.4 ± 3.1 vs 1.4 ± 1.4 g, P< 0.001), but similar for roof and floor sites. Higher power and greater impedance drops were associated with greater CF increases. Perpendicular contact had greater CF increases, followed by diagonal and parallel contact. The remaining 175 of 416 sessions demonstrated at least 1 CF decrement, typically occurring after 15 seconds of RF (group 2). This was observed least frequently at inferior PV sites. Except for minor differences in power, there were no differences in CF, tip excursion, and impedance drop between groups. Progressive CF increase during RF ablation is a distinct phenomenon that likely reflects the "push-back" effect of local myocardial swelling against the catheter tip. This may explain certain catheter-tip behaviors such as tip displacement and instability during ablation.

Self-Assembled Hydrogel Based on (Bio)polyelectrolyte Complex of Chitosan-Gelatin: Effect of Composition on Physicochemical Properties.

Taking into account the trends in the field of green chemistry and the desire to use natural materials in biomedical applications, (bio)polyelectrolyte complexes ((bio)PECs) based on a mixture of chitosan and gelatin seem to be relevant systems. Using the approach of self-assembly from the dispersion of the coacervate phase of a (bio)PEC at different ratios of ionized functional groups of chitosan and gelatin (z), hydrogels with increased resistance to mechanical deformations and resorption in liquid media were obtained in this work in comparison to a hydrogel from gelatin. It was found that at z ≥ 1 a four-fold increase in the elastic modulus of the hydrogel occurred in comparison to a hydrogel based on gelatin. It was shown that hydrogels at z ≈ 1 had an increased sorption capacity and water sorption rate, as well as increased resistance to the in vitro model environment of phosphate-buffered saline (PBS) solution containing lysozyme at 37 °C. It was also shown that in PBS and simulated gastric fluid (SGF) solutions, the effect of the polyelectrolyte swelling of the hydrogels was significantly suppressed; however, at z ≥ 1, the (bio)PEC hydrogels had increased stability compared to the samples at z < 1 and based on gelatin.

Analysis of the compound effect of mine water on coal spontaneous combustion and its application in coal fire prevention

The research on mine fire control has confirmed that the probability of CSC (Coal Spontaneous Combustion) after mine water treatment is higher than raw coal (RC). However, the current research on the effect of mine water on CSC is sketchy, which is not close to real water environment of the mine, and there is a lack of in-depth and systematic discussion on the compound effect of the characteristic components of mine water on the process of CSC. According to the actual mine environment, this paper prepared samples soaked by different types of mine water under different conditions, then the compound effect of mine water on CSC is studied by means of thermogravimetric, infrared and gas analysis. The results show that the characteristic temperature point T1 of coal samples after mine water treatment increases significantly, with a maximum increase of 11 °C, while T2-T4 decreases to different degrees, with a maximum decrease of 13 °C. The maximum apparent activation energy decreased by 32 %, which decreased by 40.6KJ/mol. The release of CO and CO2 is 1–2 times that of raw coal. The content of organic functional groups is 1.1–1.8 times higher than that of raw coal. The changes of these parameters are enhanced with the increase of acidity of mine water, which indicates that mine water can promote the spontaneous combustion activity of coal. The promoting effect mainly comes from the swelling effect of water, and the inhibiting effect is mainly related to the inorganic salts in mine water, but the inorganic salts contained in the mine water are not enough to reach the concentration that can inhibit CSC, so the overall performance of mine water is to promote the CSC. This study is conducive to understanding the influence mechanism of actual mine water environment on CSC, and provides a theoretical support for control of CSC and comprehensive utilization of mine water.

Diffusion Mechanism of Waste Crumb Rubber Composite Modified Asphalt Based on Molecular Dynamics Simulation

Waste crumb rubber composite modified asphalt (CRCMA), composed of base asphalt, waste rubber powder, and several additives (softener, activator, and cross-linking agent), has been shown to effectively improve asphalt properties. The interactions between the components in CRCMA are complex, involving molecular diffusion that significantly impacts its performance. The diffusion behavior in asphalt molecules will affect various properties of asphalt and the reasons for the different properties of asphalt can be explained by studying its diffusion mechanism. Therefore, understanding the diffusion mechanism of CRCMA is essential. The molecular dynamics simulation was employed to analyze the factors influencing the diffusion mechanism, using the diffusion coefficient as a key indicator of molecular mobility. The findings showed that the diffusion coefficient of the asphalt system decreased over time but increased with temperature. The rubber composition type also had a significant impact on diffusion, with butadiene rubber (BR) showing the highest coefficient, followed by natural rubber (NR), crumb rubber (CR), and styrene-butadiene rubber (SBR). The diffusion coefficient was the lowest and the diffusion rate was slowest after adding softeners. The diffusion coefficient increased slightly with the addition of CR, and the diffusion rate was slightly accelerated but not significantly. The diffusion coefficient increased rapidly with adding activator and the diffusion rate increased significantly. With the addition of cross-linking agent, the diffusion coefficient began to decrease and the diffusion rate became slower. The CRCMA microscopic performance tests indicated that the swelling effect of CR limits diffusion, while activators promote degradation and desulfurization of CR due to the large molecule structure getting smaller, enhancing diffusion. The S=O bond in the asphalt system was regenerated and re-crosslinked to create a mesh after adding the cross-linking agent. The small molecule structure was transformed into large one. The molecular diffusion was restricted partly and thus the diffusion rate was slowed down.

Numerical modeling and simulation for microneedles drug delivery: A novel comprehensive swelling-obstruction-mechanics model

Hydrogel microneedles have attracted significant attention in drug delivery due to their non-invasiveness and efficient administration. However, a thorough understanding of the drug transport mechanism is essential to achieve controlled drug delivery and geometry optimization of microneedles. In this study, a new swelling-obstruction-mechanics model is presented to describe the swelling and drug release behavior of hydrogel microneedles. The model integrates the swelling kinetics, the obstruction scaling of drug molecules, and the mechanical properties of hydrogel and skin and reveals the effects of swelling of the microneedle matrix and drug molecules on drug release. Subsequently, numerical simulations were conducted using the model, which enabled the optimization of hydrogel microneedle design parameters by adjusting the input variables. The results show that the geometric parameters of microneedles, especially the cross-sectional shape, have a significant effect on the drug release performance. Nevertheless, the parameters affect each other and need to be considered in the selection of a variety of factors. Additionally, penetration depth significantly affects drug release efficiency, highlighting the need for auxiliary application devices. In summary, the model advances both theoretical understanding and practical design of hydrogel microneedles, identifying key factors in drug release and optimizing their efficiency and reliability for clinical applications.

Chemically Bonded Graphene Oxide/Covalent Organic Framework Nanosheets as Robust Membranes for Fast Desalination.

Graphene oxide (GO) is widely used to prepare 2D laminar separation membranes because of its single atomic thickness and good processability. However, due to the tortuous transport path and excessive swelling effect, it is difficult to improve permeability, salt rejection, and stability of GO membranes simultaneously. Herein, we chemically laminated GO with covalent organic framework nanosheets (CONs) to fabricate membranes for fast and stable desalination. GO and CONs are first vacuum-filtrated and then heated, obtaining chemically bonded GO/CON (c-GO/CON) laminar membranes. CONs provide additional short transport pathways through intrinsic in-plane pores and stabilize interlayer channels by forming chemically cross-linked networks with GO. As a result, rapid transmembrane water permeation and improved desalination performances are achieved. Moreover, the prepared c-GO/CON membranes show excellent stabilities in filtration processes with complex environments, such as acidic and basic conditions, elevated pressures, concentrated salinities, and long-term operations. This study provides a new idea for the preparation of high-performance graphene-based nanofiltration membranes.

Experimental and numerical investigation of dynamic characteristics and safe mooring criteria of moored outfitting ships under swell conditions

Outfitting ships are characterized by a small draft and a large wind area. As a kind of unpowered ship, when subjected to strong lateral loads, excessive sway motion could cause cable breakage, resulting in potential ship damage or casualties. In this paper, physical and numerical model experiments have been carried out to investigate the effects of swells on moored outfitting ships. The data is analyzed in time and frequency domains to discover the relationship between swells, mooring patterns, ship motions and mooring forces. Subsequently, a numerical model is developed in AQWA, and in conjunction with the physical model experiments, safe mooring criteria for outfitting ships under swell are proposed. Results show that both reducing the sea severity and increasing the number of cables is effective in reducing the risk of cable breakage. The horizontal and heave motions of outfitting ships are controlled by swell period, while the roll and pitch motions are mainly controlled by own parameters. For the cables at different locations, the bow/stern line, breast line and spring line are mainly controlled by sway/yaw motions, sway motion and surge motion, respectively. Additionally, the safe mooring criteria could be widely applied to outfitting quays to ensure the safe operation.

Experimental and molecular simulation of carbon dioxide solubility in hexadecane at varying pressures and temperatures

CO2-EOR can make underground storage efforts possible, addressing both energy demands and climate issues. This study establishes an in-situ method to measure the degree of CO2 solubility in hexadecane in a wide range of P-T conditions. CO2 and hexadecane with known volumes were mixed in silica capillaries and examined by Raman spectroscopy after reaching an equilibrium at certain P-T condition to establish a relationship between mole fraction of CO2 in hexadecane and ratio of Raman peak area. Results showed that solubility of CO2 decreases with increasing temperature and increases with pressure. Complementing the experimental data, hybrid grand canonical Monte Carlo/molecular dynamics (GCMC/MD) simulations were performed to study the swelling effect of CO2/hexadecane system and the diffusion of CO2 within hexadecane. Simulation results were validated against Raman spectroscopy and previously published CO2 solubility data, as well as a genetic algorithm-based (GA) predictive model, all matching with high accuracy and conforming each other. Based on molecular simulation results, the necessity of accounting for volumetric changes in solubility calculations to enhance the accuracy of predictive models in similar systems was revealed. Additionally, in contrast to temperature, the effect of pressure on the diffusion coefficient remains relatively minimal. Ultimately, this study provides solutions for in-situ probing techniques to determine the solubility of various fluids in a wide range of P-T conditions, processes supporting CO2-EOR and carbon storage operations underground.

The effect of clay swelling on crack generation in red stratum soft rock during water-induced disintegration: a matrix-based discrete element simulation study

The effect of clay swelling on crack generation in red stratum soft rock during water-induced disintegration: a matrix-based discrete element simulation study

Swelling Behavior of Acrylate-Based Photoresist Polymers Containing Cycloaliphatic Groups of Various Sizes.

Photoresist polymers containing cycloaliphatic acrylic monomers have been synthesized for use in the microcircuits of semiconductors. Although cycloaliphatic acrylic monomers exhibit a high etch resistance and excellent thermal properties, their large size increases the distance between the main chains of the resulting polymers. This increased distance facilitates the penetration of a developer between the main chains, which leads to swelling and thus pattern collapse, distortion, and delamination, thereby complicating the fabrication of microcircuits. To solve this problem, various large developers were used in previous studies to reduce the swelling effect. However, these developers could not easily dissolve the unexposed regions of the resist. To overcome this issue, we designed photoresist polymers with smaller functional groups to decrease the degree of swelling. Specifically, ArF photoresist polymers were synthesized from monomers with various sizes of functional groups. We confirmed that the polymer synthesized using cyclohexyl methacrylate (CHMA), which had the smallest functional group, exhibited the shortest distance between the main chains. Consequently, this polymer showed the least swelling, with a swelling ratio of 109%. In contrast, the polymers synthesized using isobornyl acrylate (IBOA) and dicyclopentanyl methacrylate (TCDMA), which have large functional groups, exhibited greater distances between the main chains, resulting in swelling ratios of 114% and 112%, respectively. The polymer with a swelling ratio of 109% showed excellent patterning properties, while those with swelling ratios of 114% and 112% were delaminated by the developer. Our work introduces a novel approach to help reduce the swelling effect and achieve high-quality patterns in negative photoresists.

The mechanism of pore pressure and adsorption swelling effect on permeability during geological storage of carbon dioxide in coal seams

Unmineable coal seams serve as ideal sites for CO2 geological sequestration, with permeability being a critical indicator for evaluating the storage capacity of coal seams. After CO2 injection, coal seam permeability undergoes continuous changes. Higher injection pressure enhances CO2 flow capacity in the coal seam and improves the injectivity; However, it also induces significant adsorption swelling deformation in the coal, leading to a decline in coal permeability. Using the non-adsorptive gas He as a reference, isothermal-non-isobaric injection experiments were conducted to measure the strain characteristics of the coal at various distances from the injection port. Based on the experiments, a model for the evolution of pore pressure in the coal was developed, changes of apparent permeability during the injection process were calculated, and the mechanisms by which pore pressure and adsorption swelling affect permeability were elucidated. The results indicate that, within the experimental pressure range, the compression deformation of coal pore surfaces caused by pore pressure accounts for less than 3 % of the total coal deformation. However, the increase in permeability resulting from pore surface compression exceeds the reduction in permeability induced by adsorption swelling. The farther from the injection point, the lower the pore pressure and the smaller the apparent permeability of the coal. With the injection pressure increasing, the loss of pore pressure along the gas flow direction also increases. The apparent permeability of the coal is determined by the combined effects of pore pressure and adsorption swelling during CO2 injection. In the initial injection stage, pore pressure results in elastic compression deformation of the coal matrix, leading to a rapid increase in apparent permeability. Permeability gradually reduces due to adsorption swelling. Higher injection pressure results in greater elastic compression deformation of the coal pore surfaces, which increases pore aperture and permeability.

Anti‐Swelling 3D Nanohydrogel for Efficient Osmotic Energy Conversion

AbstractOsmotic energy conversion based on reverse electrodialysis (RED) technology has attracted intense attention. As the key component, the ion‐selective membranes should meet the basic requirements of high power density, high mechanical strength, and easy preparation. Polyelectrolyte hydrogel materials are good candidates, due to their high charge density. However, the severe swelling effect decreases the ion selectivity and mechanical strength. To solve this problem, an anti‐swelling 3D nanohydrogel is demonstrated, which is in situ polymerized in the nanoporous polyimide (PI) membrane, exhibiting ultrahigh power density in osmotic energy conversion. Because of the nano‐confinement of the PI matrix, the swelling ratio of the nanohydrogel decreases to 37.5% from 593.2% of the bulk hydrogel. Meanwhile, the hybrid membrane exhibits excellent mechanical strength (≈89.5 MPa). Under a 500‐fold concentration gradient, the nanohydrogel generates a power density of up to 48.5 W m−2, one order of magnitude higher than that of the bulk hydrogel. The anti‐swelling 3D nanohydrogel introduces a new concept in designing separation membranes for osmotic energy conversion.