Liquid Absorption Research Articles

Anisotropic Shape‐Memory Cryogel with Oriented Macroporous Channel for Hemorrhage Control and Tissue Generation

AbstractInjectable shape‐memory materials represent a promising solution for managing severe bleeding from deep, inaccessible wounds. However, many existing expandable hemostats consist of randomly porous networks and often exhibit inadequate liquid absorption, non‐degradability, and potential cytotoxicity, which limits their effectiveness in hemostasis and wound repair. To overcome these challenges, this study introduces an anisotropic hemostatic cryogel, SALC, featuring oriented macroporous channels made from biocompatible polymers (poly(ethylene glycol), gelatin, and lignin) through a simple one‐step cryo‐structuration process. This structural alignment provides the cryogel with low water flow resistance, efficient fluid transport, and rapid shape recovery. SALC demonstrates superior liquid adsorption and retention, in vitro tamponade sealing, and pro‐coagulant properties compared to commercial gelatin sponges and XSTAT, along with favorable biocompatibility and biodegradability. The hemostatic efficacy of SALC surpasses clinically used counterparts in rat models of liver perforation and femoral artery transection. Remarkably, SALC achieves effective hemostasis in porcine models of severe hepatic, femoral artery, and cardiac injuries. Additionally, this anisotropic cryogel supports liver tissue regeneration by promoting cell migration and angiogenesis while mitigating inflammatory responses. The cryogel is also lightweight and easy to carry and implement. Overall, SALC shows promising clinical applications for treating severe hemorrhages and improving wound healing.

Analysis on the Impact of Industrial Agents on 3D-printed Polymeric Materials in Soft Robotics

The study investigates the effects of aggressive factors environments commonly found in industrial environments on the elastomeric material TPU 95 A, which is integrated into a multitude of soft robotics applications. Specimens made of TPU 95 A were subjected to aggressive liquid media - cooling oil, distilled water, and ultraviolet radiation (UV-C) to evaluate changes in their mechanical and elastic properties following uniaxial tensile tests. The research, carried out using additive manufacturing technology, highlights the importance of monitoring how the external factors impact elastic and mechanical characteristics of TPU 95 A material. The results obtained after the experimental tests proves to us that the aggressive media analyzed had a greater or lesser influence on the material. By uniaxial tensile tests, it was found that the liquid absorption had a very important impact on the tensile strength of the material. For example, at 1.02% absorption in distilled water, the maximum value of the ultimate strain decreased by 0.257 mm/mm, and at 3.06% absorption in cooling oil, the maximum value of the strain decreased by 0.672 mm/mm.

Effect of Tetrapropylammonium Chloride Quaternary Ammonium Salt on Characterization, Cytotoxicity, and Antibacterial Properties of PLA/PEG Electrospun Mat.

In this study, poly(lactic acid) (PLA)-tetrapropylammonium chloride (TCL)-poly(ethylene glycol) (PEG) nonwoven networks were produced using PLA, PEG with different concentrations (3, 5, 7, and 9 wt%), and TCL. PEG is included as a plasticizer in PLA polymer, which has high biocompatibility but a brittle structure. The importance of this study is to investigate the effect of TCL salt on the characterization of PLA-PEG nanofibers. For this research, the cytotoxicity test system responsible for the fibroblast cell line (L929) was evaluated with the liquid absorption capacity (LAC) and drying time tests for its use in wound dressings. The addition of TCL salt reduced bead formation in PLA-PEG nanofibers and increased the homogeneity of fiber dispersion. The smoothest and most homogeneous nonwoven networks were obtained as PLA-5TCL-PEG. It was also reported that this nonwoven network exhibited liquid absorption behavior with a maximum increase of 150% compared to the PLA-PEG nonwoven network and had the highest Young's modulus value of 12.97 MPa. In addition to these tests, evaluations were made with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), drying time test, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and mechanical tests. In addition, high cell viability was observed in L292 mouse fibroblast cells at the end of the 24th hour, again with the effect of TCL salt. In addition, antibacterial activity was tested against gram-negative E. coli and gram-positive S. aureus bacteria, and it was observed that there was no antibacterial activity. Since PLA-TCL-PEG nonwoven webs have a maximum cell viability of 133.27%, they are recommended as a potential dermal wound dressing.

Imidazolium-based and pyridinium-based ionic liquids for methyl chloroacetate absorption

Imidazolium-based and pyridinium-based ionic liquids for methyl chloroacetate absorption

Deep eutectic effect enhanced proton transfer for highly efficient CO2 capture with a novel nonaqueous ionic liquid absorbent

Deep eutectic effect enhanced proton transfer for highly efficient CO2 capture with a novel nonaqueous ionic liquid absorbent

Polyanionic Electrolyte Ionization Desalination Empowers Continuous Solar Evaporation Performance.

Solar evaporation contributes to sustainable and environmentally friendly production of fresh water from seawater and wastewater. However, poor salt resistance and high degree of corrosion of traditional evaporators in brine make their implementation in real applications scarce. To overcome such deficiency, a polyanionic electrolyte functionalization strategy empowering excellent uniform desalination performance over extended periods of time is exploited. This 3D superhydrophilic graphene oxide solar evaporator design ensures stable water supply by the enhanced self-driving liquid capillarity and absorption at the evaporation interface as well as efficient vapor diffusion. Meanwhile, the polyanionic electrolyte functionalization implemented via layer-by-layer static deposition of polystyrene sodium sulfonate effectively regulates/minimizes the flux of salt ions by exploiting the Donnan equilibrium effect, which eventually hinders local salt crystallization during long-term operation. Stable evaporation rates in line with the literature of up to 1.68kg m-2 h-1 are achieved for up to 10 days in brine (15‰ salinity) and for up to 3 days in seawater from Hangzhou Bay in the East China Sea (9‰ salinity); while, maintaining evaporation efficiencies of ≈90%. This work demonstrates the excellent benefits of polyanionic electrolyte functionalization as salt resistance strategy for the development of high-performance solar powered seawater desalination technology and others.

Carbon-Nanotube-Based Superhydrophobic Magnetic Nanomaterial as Absorbent for Rapid and Efficient Oil/Water Separation.

In this work, the simple fabrication of a new superhydrophobic magnetic sponge based on CNTs, NiFe2O4 nanoparticles, and PDMS was investigated. CNTs were synthesized by chemical vapor deposition (CVD) on a nickel ferrite catalyst supported on aluminum oxide (NiFe2O4/Al2O3). The synthesis of nickel ferrite (NiFe) was accomplished using the sol-gel method, yielding magnetic nanoparticles (43 Am2kg-1, coercivity of 93 Oe, 21-29 nm). A new superhydrophobic magnetic PU/CNT/NiFe2O4/PDMS sponge was fabricated using a polyurethane (PU) sponge, CNTs, NiFe2O4 nanoparticles, and polydimethylsiloxane (PDMS) through the immersion coating method. The new PU/CNT/NiFe2O4/PDMS sponge exhibits excellent superhydrophobic/oleophilic/mechanical properties and water repellency (water absorption rate of 0.4%) while having good absorption of oil, olive oil, and organic liquids of different densities (absorption capacity of 21.38 to 44.83 g/g), excellent separation efficiency (up to 99.81%), the ability to be reused for removing oil and organic solvents for more than 10 cycles, and easy control and separation from water using a magnet. The new PU/CNT/NiFe2O4/PDMS sponge is a promising candidate as a reusable sorbent for collecting oil and organic pollutants and can also be used as a hydrophobic filter due to its excellent mechanical properties.

Advancing Offshore Wind Turbine modeling: developing an integrated tool for structural control

This paper presents the modeling of a 22 MW OWT (IEA Wind 22-Megawatt Offshore Reference Wind Turbine), intended for integration into a new MATLAB-based user-friendly interface. Users can select from turbines ranging from 5 to 22 MW, inputting relevant data on wind and maritime conditions, and other relevant data. Significantly advancing prior research utilizing a 5 MW NREL OWT, this study encompasses hydrodynamic and aerodynamic modeling of a flexible tower to assess response peaks at the OWT hub, evaluated via Power Spectral Density analysis. The routine models the tower, incorporating a rotational spectrum to account for blade rotation effects. The developed tool may include the incorporation of vibration absorbers for structural control, such as pendulum, inertial, or liquid column absorbers, among others.

Zr-MOF/MXene composite for enhanced photothermal catalytic CO2 reduction in atmospheric and industrial flue gas streams

In this study, a novel composite was engineered by integrating Zr-MOF (NH2-UIO-66) with MXene layers through electrostatic self-assembly. Under simulated sunlight and at 80 °C, this composite material achieved nearly complete conversion of low-concentration atmospheric CO2 to CO and CH4 without additional sacrificial agents or alkaline absorption liquids, marking one of the few reports demonstrating near-complete reduction of low-concentration CO2 directly from the air. For high-concentration CO2 in industrial flue gas, the composite utilized residual heat at 80 °C without additional energy input, exhibiting excellent CO2 reduction efficiency with CO and CH4 production rates of 127 μmol·g-1·h-1 and 330 μmol·g-1·h-1, respectively, resulting in a total production rate 4.76 times higher than that in the air. Compared to most reports on thermocatalytic CO2 reduction (>300 °C), this material shows significant advantages below 100 °C. The performance improvement is attributed to the introduction of Zr-MOF, which provides additional active sites and reduces activation energy. Additionally, the localized surface plasmon resonance (LSPR) effect of MXene facilitates the migration of thermal charge carriers to Zr4+ sites within the MOF. Density Functional Theory (DFT) calculations validate these findings. Overall, Zr-MOF/MXene composite holds potential for reducing CO2 in air and industrial settings, advancing energy conversion and environmental management.

Micro-Nanofiber Three-Dimensional Antibacterial Sponge with Wetting/Pore Dual Gradient for Rapid Liquid Infiltration and Uniform Retention in Diapers.

The core layer of disposable diapers typically contains a blend of superabsorbent polymer (SAP) and pulp, resulting in slow liquid absorption, layer separation, reverse osmosis, and potential skin issues owing to the addition of antibacterial agents to the surface layer. Therefore, a core layer with rapid liquid absorption, uniform retention, and antibacterial properties must be developed to improve wearer comfort. In this study, a three-dimensional network porous structure for the core layer of a disposable diaper was prepared by solution blow spinning (SBS). This structure comprised a superabsorbent fiber (SAF) and hydrolyzed polyacrylonitrile (HPAN) micro/nanofibers with a dual gradient in wetting/pore size. Progressively increasing the SAF content in each layer to incrementally increase wettability and controlling fiber diameter, a gradient pore structure with sizes of approximately 30 μm-16 μm-7 μm was formed. This design exhibited rapid infiltration capability, reducing the third liquid infiltration time by 13 s compared to those of commercial core layers while reducing reverse osmosis by 1.4 g, and the liquid absorption and retention rates are 47.7 times and 46.1 times, respectively, which is 1.6 times higher than those of commercial diapers. In addition, incorporating a natural antibacterial agent, ε-poly-l-lysine hydrochloride (ε-PLH), into the core layer resulted in an antibacterial rate exceeding 99.99% without direct contact with the skin; water transport capacity tests confirmed faster liquid infiltration speed, uniform absorption, and no fault formation.

CONTROL MODEL OF THE NATURAL GAS PURIFICATION PROCESS

The equipment used in the processes of cleaning and drying natural gas for transportation and consumption and the methods applied for drying gas were comparatively analyzed, it was noted that the absorption method is more widespread among these methods due to its simplicity and efficiency, it was shown that drying gas should be carried out immediately after its cleaning from mechanical and other impurities so that during the transportation and use of gas, there are no blockages in pipelines, malfunctions in measuring devices and other gas equipment. Drying gas prevents the formation of hydrates in pipes due to condensation during transportation and increases the heat-generating capacity of gas by burning it well. The characteristics of the liquid absorbent used to dry gas in the absorption process - the absorbent, being regenerated and returned to the gas drying process were investigated, and the parameters and quality indicators affecting the technological process were determined for optimal control of the gas drying technological process at normal temperature and pressure for that process, as well as the output parameters of the gas drying unit. It was noted that although the pneumatic control system is considered morally obsolete, some elements and devices of this system, in particular, pneumatic actuators, are distinguished by their reliability in mining and field conditions. Therefore, it is advisable to use them in modern control systems with controllers. For this purpose, the structure of the general control system of the process, the information model of the control object was built, the input and output parameters, the limiting conditions for reflecting the exciting and controlling effects in the structure of the mathematical model were determined, and the limit ranges containing the minimum and maximum values of each parameter were determined. The control problem can also be formulated and solved as a problem of stabilizing productivity or another parameter. An optimal control model of the gas drying process was built, and the optimization criterion was selected. In the problem of optimizing the technological process of gas drying, the maximum productivity of the plant was adopted as the main criterion, and the humidity of the gas was adopted as the limiting condition. Several recommendations are given for solving this problem. Keywords: gas drying, absorbent, control system, optimal control, model.

Liquid CO2-Capture Technologies: A Review.

Escalating global carbon dioxide (CO2) emissions have significantly exacerbated the climate impact, necessitating imperative advancements in CO2-capture technology. Liquid absorbents have received considerable attention in carbon capture for engineering applications, due to their high flexibility, reliability, and recyclability. Nonetheless, the existing technologies of liquid CO2 capture suffer from various issues that cannot be ignored, such as corrosion, elevated costs, and pronounced secondary pollution. More efforts are required to realize process optimization and novel absorbent innovation. This review presents nanofluids and other novel liquid absorbents such as ionic liquids, amino acids, and phase-change absorbents. The preparation, mechanisms of action, and influencing factors of nanofluid absorbents are discussed in detail to provide researchers with a comprehensive understanding of their potential applications. Further, the challenges (including energy loss, environmental and human health, barriers to application and capture performance, etc.) encountered by these innovative absorbents and techniques are also commented on. This facilitates side-by-side comparisons by researchers.

Theory of Gas Purification by Liquid Absorber in Small Rotating Channels with Application to the Patented Rotational Absorber Device

A new design for absorbing vapour-phase impurities from gases is presented. It consists of small channels packed in a rotating vertical cylinder. Gas flows through the channels adjacent to a thin film of absorber liquid. The liquid film is pressed to the radially outward side of each channel by the centrifugal force and flows downwards by gravity. Formulae are presented which describe the concentration distributions of gaseous impurities subject to absorption in gas and liquid. Results include expressions for laminar and turbulent diffusion coefficients to be used in mass balance equations. The role of rotation is quantified including the effect on wavy motion and enhanced diffusion in the liquid layer. Application in design is indicated for the case of separation of the greenhouse gas CO2 from flue gases of fossil fuel combustion processes. At other equal dimensions, the height of the Rotational Absorber Device is calculated to be 25 times shorter than the enormous heights of conventional tray and packed columns.

Ultra-Fast, Unidirectional Water Absorption on Wood Ear.

Materials exhibiting rapid, unidirectional liquid absorption are desirable for comfort textiles and wound dressings. Implementing chemical or structural gradient along the vertical axis of substrates is an effective way to achieve such properties. Liquid's lateral spreading across the substrate affects area occurring vertical imbibition. However, the influence of lateral spreading on liquid's overall absorption remains unexplored. Findings on ultra-fast, unidirectional water absorption on the abhymenium of wood ear fungi are presented, featuring dense micro-sized hairs atop a porous sublayer containing smaller micro-/nano-pores. These hairs facilitate lateral spreading, and the gradient-sized structures from the surface hairs to the internal pores enhance capillary force, promoting efficient vertical imbibition. The synergistic wicking mechanism in both directions shortens absorption time of a 1-µL droplet by two orders of magnitude compared to a solely porous surface (35 ms vs 5.2 s). An artificial micro-pillar array on a porous substrate also exhibits ultra-fast, unidirectional water absorption. This study advances the understanding of liquid dynamics in porous media and provides a blueprint for engineering materials with superior liquid management.

Fluid Imbibing Super Absorbent Textiles for Comfort Wear Performance

Textile is a basic human need, it not only provides the aesthetic appeal but also imparts necessary sweat absorption and relevant functional effects. The textile material is widely used for various hygiene and comfort wear applications where the absorption as well as leak proof retention of various body fluids is an essential parameter. This effect is achieved when the textile material is treated with suitable super absorbent chemicals. Superabsorbent finishes are polymeric coatings that significantly enhance the liquid absorption capacity of textile substrates. Known as superabsorbent polymers (SAPs), these materials can be natural, synthetic, or hybrid, characterized by their high degree of cross-linking and three-dimensional network structure. Capable of absorbing up to 100,000% of their weight in water, SAPs form stable hydrogels due to their hydrophilic groups. These properties make them suitable for diverse applications, including hygiene products, water purification, horticulture, and pharmaceuticals. In the past few decades, super absorbent polymers and fibres have found a lot of applications, especially in the field of textiles. This report briefly discusses the various application fields of SAP in textiles. With applications in hygiene products, medical textiles, protective apparel, automotive textiles, and geotextiles, the study explores how SAPs are incorporated into textile fibres (SAFs) to improve moisture absorption and management. Lastly, a comprehensive outlook for the future is given, highlighting encouraging prospects in SAP-based textile research and industry.

Chondroitin sulfate sponge scaffold for slow-release Mg2+/Cu2+ in diabetic wound management: Hemostasis, effusion absorption, and healing

The management of diabetic wounds presents significant challenges due to persistent inflammation, microenvironmental disruptions, and impaired angiogenesis. To address these issues, this study developed a multifunctional chondroitin sulfate sponge (CSP@Cu-Mg) with anti-inflammatory properties, hemostatic effects, effusion absorption, and enhanced healing promotion. Through ion crosslinking, MgO and CuO were incorporated into the interpenetrating network structure of chondroitin sulfate and acellular dermal matrix, resulting in a sponge with impressive liquid absorption capacity (3450 %) and porosity (83 %). This sponge enabled sustained release of Mg2+/Cu2+ ions, with approximately 40 % cumulative release over 7 days. This release helped reduce inflammation, promote the proliferation and migration of skin repair-related cells, and stimulate angiogenesis. In vivo studies demonstrated that the CSP@Cu-Mg sponge significantly improved diabetic wound healing by modulating inflammation and accelerating collagen deposition, angiogenesis, and re-epithelialization. This extracellular matrix sponge, which synergistically releases Mg2+/Cu2+, presents a promising strategy for comprehensive diabetic wound management with substantial clinical implications.

Exergy-economic based multi-objective optimization and carbon footprint analysis of solar thermal refrigeration systems

The increasing carbon footprint associated with conventional cooling methods underscores the urgent need for sustainable alternatives. This study investigates the economic and environmental advantages of various solar-thermal cooling systems, with a focus on optimizing their performance across different climate conditions. Employing a multi-objective approach, the research emphasizes exergy-economic indices to optimize selected cycles. The analysis covers multiple refrigeration technologies, including liquid absorption, solid adsorption, and solid desiccant cycles. Results indicate that the liquid absorption cycle performs optimally in hot, arid climates, reducing the payback period to approximately 8 years when optimized. In hot and humid regions, the solid desiccant cycle proves most effective due to its superior humidity control, yielding a payback period of 5.3 years. For cold and mountainous areas, the solid adsorption cycle is preferred, with a payback period of 13.5 years, while moderate and humid climates benefit from the solid desiccant cycle for both cooling and humidity regulation. The exergy-economic factors for the solar refrigeration systems across semi-arid, hot and arid, hot and humid, cold and mountainous, and moderate and humid climates are 0.758, 0.602, 0.698, 0.74, and 0.575, respectively.

Semi-active omnidirectional liquid column vibration absorber with rapid frequency adjustment capability

This paper explores the semi-active omnidirectional liquid column vibration absorber, a unique tuned liquid column damper consisting of multiple circularly distributed columns for the control of vibrations in all lateral directions. Each column features actuator-controlled cells that can trap liquid and adjust column cross-sections, facilitating a rapid shift in natural frequency during operation. Unlike previous semi-active tuned liquid column dampers, this design can modulate its natural frequency without altering the total liquid mass and eliminate the need for overpressure or additional springs. Validation is conducted on a full-scale omnidirectional prototype. However, the trapped liquid mass plays a crucial role in determining the damper’s optimal tuning parameters and affects the resulting restoring force, emphasizing its significance in the design process. This research introduces a comprehensive mathematical model of the absorber, accompanied by a control algorithm, and proposes a corresponding design approach. Moreover, a shape function informed by experimental damping is developed to address complexities arising from geometry and cell arrangements. The focus of the study is the lateral vibration control of high-rise civil engineering structures. Numerical and experimental analyses demonstrate the superior adaptability of the absorber to fluctuating structural properties, marking a significant improvement over its passive counterpart in various loading scenarios.

Highly efficient CO2 capture by a non-aqueous amine-based absorbent of 3 aminopropanol/polyethylene glycol 200: Experimental and computational simulation

In the present work, a novel non-aqueous 3-aminopropanol/polyethylene glycol 200 (3AP/PEG200) absorbent for efficient carbon dioxide (CO2) capture was designed using environment-benign and non-toxic polyethylene glycol 200 (PEG200) as an alternative to water. The mechanism, physical, thermodynamic, and kinetic properties of absorption process was investigated through a combination of experimental and multi-scale computational simulation approaches including molecular dynamics (MD) simulation and quantum chemical (QC) calculations. It was found that the addition of PEG200 not only enhanced the thermal stability of the absorbent, but also did not significantly increase the viscosity. In addition, kinetic studies revealed that the absorption process conforms to a pseudo-first-order equation, with the activation energy (Ea) value of 20.40 kJ/mol, significantly lower than that of the benchmark 30 % monoethanolamine (MEA) aqueous solution used in industrial CO2 capture. Furthermore, the enthalpy change (ΔH) and entropy change (ΔS) values were found to be more negative than those of other liquid absorption systems, indicating that the 3AP/PEG200 absorbent is favorable for CO2 absorption even at low partial pressures. Most importantly, the absorption system exhibited good regeneration capability, as demonstrated by five absorption–desorption cycle experiments. In conclusion, the non-aqueous 3AP/PEG200 absorbent exhibits low viscosity, high thermal stability, enhanced absorption capacity, and excellent cyclic performance, positioning it as a promising candidate for CO2 absorption in industrial applications.

Physicochemically modified polymer-based fluidic gates with tunable wetting properties for intelligent liquid manipulations

The creation of a selective flow path and the regulation of a flow rate are of critical importance for polymer-based devices that manipulate liquid at the microscale. The formation of a 3D interconnected network of voids (i.e., physical volumetric modification) and the addition of a nonionic surfactant, Silwet L-77, (i.e., chemical volumetric modification) are expected to affect the wetting properties of polymers, thereby achieving selective gating effect in the polymer-based devices as an appropriate technology. Here, a set of polydimethylsiloxane (PDMS)-based fluidic gates (F-gates) were developed to enable selectivity for liquids and flow-rate control of the liquids by tuning the wetting properties of PDMS with the physicochemical volumetric modifications. For water and oil with different surface tensions (STs), the effects of the physical and chemical volumetric modifications on the fluidic gating of PDMS were quantitatively characterized in terms of contact angle, mass flow rate, and liquid absorption speed. The applicability of PDMS-based F-gates to the selective separation of oil and water even from oil-in-water emulsion was demonstrated by fabricating Janus PDMS-based F-gates. Our physicochemical volumetric modifications were also extensively analyzed to examine whether they satisfy the technological, economic, and ecological requirements of appropriate technology. This is the first effort to tailor the wetting properties of PDMS through physicochemical volumetric modifications, thus configuring a set of PDMS-based F-gates that act both as a separator for liquids of different STs and as a switch for fluid flows.