Hydrogel-coated Mesh Research Articles

Hydrogel Coated Mesh with Controlled Flux for Oil/Water Separation.

Superwetting surfaces are often applied in oil/water separation. Hydrogels have been widely prepared as superhydrophilic/underwater superoleophobic materials for oil/water separation since they are naturally hydrophilic. Hydrogels usually need to be combined with porous substrates such as stainless steel mesh (SSM) due to their poor mechanical properties. However, it is usually inevitable that the pores of the substrate are clogged during the actual preparation process, leading to a significant decrease in the flux, which limits its effective application. In this study, acrylic acid (AA), chitosan (CS) and modified silica were utilized to form a layer of dual-network PAA/CS@SiO2 hydrogel by photopolymerization on SSM, followed by a simple and novel ultrasonic-assisted pore-making method to generate numerous pores in situ on the surface of the hydrogel-coated mesh, which led to an increase in water flux from 0 to 70,000 L m-2 h-1 without decreasing the separation efficiency. After 100 separations of a mixture of n-hexane and water, the flux was still higher than 50,000 L m-2 h-1 with a separation efficiency above 99%, which is superior to most of hydrogel-coated meshes reported so far. Moreover, the prepared PAA/CS@SiO2 hydrogel-coated mesh also has good environmental stability, low swelling, and self-cleaning properties. We believe that the strategy of this study will provide a simple new perspective when hydrogels block the substrate pores, resulting in low water flux.

Antibacterial Nano-Architected CS/PVA/s-triazine Hydrogel-Coated Mesh for Oil/Water Emulsion Separation

Antibacterial Nano-Architected CS/PVA/s-triazine Hydrogel-Coated Mesh for Oil/Water Emulsion Separation

Superhydrophilic and Underwater Superoleophobic Copper Mesh Coated with Bamboo Cellulose Hydrogel for Efficient Oil/Water Separation.

Super-wetting interface materials have shown great potential for applications in oil-water separation. Hydrogel-based materials, in particular, have been extensively studied for separating water from oily wastewater due to their unique hydrophilicity and excellent anti-oil effect. In this study, a superhydrophilic and underwater superoleophobic bamboo cellulose hydrogel-coated mesh was fabricated using a feasible and eco-friendly dip-coating method. The process involved dissolving bamboo cellulose in a green alkaline/urea aqueous solvent system, followed by regeneration in ethanol solvent, without the addition of surface modifiers. The resulting membrane exhibited excellent special wettability, with superhydrophilicity and underwater superoleophobicity, enabling oil-water separation through a gravity-driven "water-removing" mode. The super-wetting composite membrane demonstrated a high separation efficiency of higher than 98% and a permeate flux of up to 9168 L·m-2·h-1 for numerous oil/water mixtures. It also maintained a separation efficiency of >95% even after 10 cycles of separation, indicating its long-term stability. This study presents a green, simple, cost-effective, and environmentally friendly approach for fabricating superhydrophilic surfaces to achieve oil-water separation. It also highlights the potential of bamboo-based materials in the field of oil-water separation.

Anisotropic elastic behavior of a hydrogel-coated electrospun polyurethane: Suitability for heart valve leaflets

Although xenograft biomaterials have been used for decades in replacement heart valves, they continue to face multiple limitations, including limited durability, mineralization, and restricted design space due to their biological origins. These issues necessitate the need for novel replacement heart valve biomaterials that are durable, non-thrombogenic, and compatible with transcatheter aortic valve replacement devices. In this study, we explored the suitability of an electrospun poly(carbonate urethane) (ES-PCU) mesh coated with a poly(ethylene glycol) diacrylate (PEGDA) hydrogel as a synthetic biomaterial for replacement heart valve leaflets. In this material design, the mesh provides the mechanical support, while the hydrogel provides the required surface hemocompatibility. We conducted a comprehensive study to characterize the structural and mechanical properties of the uncoated mesh as well as the hydrogel-coated mesh (composite biomaterial) over the estimated operational range. We found that the composite biomaterial was functionally robust with reproducible stress–strain behavior within and beyond the functional ranges for replacement heart valves, and was able to withstand the rigors of mechanical evaluation without any observable damage. In addition, the composite biomaterial displayed a wide range of mechanical anisotropic responses, which were governed by fiber orientation of the mesh, which in turn, was controlled with the fabrication process. Finally, we developed a novel constitutive modeling approach to predict the mechanical behavior of the composite biomaterial under in-plane extension and shear deformation modes. This model identified the existence of fiber–fiber mechanical interactions in the mesh that have not previously been reported. Interestingly, there was no evidence of fiber–hydrogel mechanical interactions. This important finding suggests that the hydrogel coating can be optimized for hemocompatibility independent of the structural mechanical responses required by the leaflet. This initial study indicated that the composite biomaterial has mechanical properties well-suited for replacement heart valve applications and that the electrospun mesh microarchitecture and hydrogel biological properties can be optimized independently. It also reveals that the structural mechanisms contributing to the mechanical response are more complicated than what was previously established and paves the pathway for more detailed future studies.

Surface Modification of Polypropylene Mesh with a Porcine Cholecystic Extracellular Matrix Hydrogel for Mitigating Host Tissue Reaction.

Polypropylene (PP) meshes are widely used for repairing skeletal muscle defects like abdominal hernia despite the chances of undesirable pro-inflammatory tissue reactions that demand revision surgeries in about 45% of cases. Attempts have been made to address the problem by modifying the mesh surface and architecture. These procedures have yielded only incremental improvements in the management of overall postoperative complications, and the search for a clinically viable therapeutic strategy continues. This study deployed a tissue engineering approach for mitigating PP-induced adverse tissue reaction by dip-coating the mesh with a hydrogel formulation of the porcine cholecystic extracellular matrix (CECM). The biomaterial properties of the CECM hydrogel-coated PP (C-PP) meshes were studied and their biocompatibility was evaluated by in vitro and in vivo tests based on ISO standards. Further, the nature of tissue reactions induced by the hydrogel-coated mesh and a commercial PP hernia repair graft was compared in a rat model of partial-thickness abdominal wall defect. Histomorphologically, in comparison with the PP graft-induced tissue reaction, C-PP caused a favorable graft-acceptance response characterized by reduced numbers of pro-inflammatory M1 macrophages and cytotoxic lymphocytes. Remarkably, the differential inflammatory response of the C-PP graft-assisted healing was associated with a fibrotic reaction predominated by deposition of type I collagen rather than type III collagen, as desired during skeletal muscle repair. It was concluded that the CECM hydrogel is a potential biomaterial for surface modification of polymeric biomedical devices.

Facile fabrication of super-hydrophilic cellulose hydrogel-coated mesh using deep eutectic solvent for efficient gravity-driven oil/water separation

The development of sustainable, low-cost, green and efficient oil–water separation materials is an attractive and challenging work. Oil/water separation process has been achieved by a variety of materials with special wettability, but most materials require complex instruments or involve toxic and corrosive chemicals, which might lead to some potential economic and environmental issues. Our work proposed here is a novel super-hydrophilic, underwater super-oleophobic cellulose hydrogel-coated mesh (CHCM) which produced by deep eutectic solvent, aimed for efficient gravity-driven oil/water separation. Based on this pre-wet CHCM, the separation efficiency of various oil–water mixtures was above 98.0%, and the results also showed that CHCM has good recyclability and durability, even after 20 cycles, the separation efficiency also maintained at 98.5%. Impressively, the prepared CHCM also exhibited good salt resistance; it can separate a high efficiency pump oil mixture from a saturated aqueous NaCl solution. Through XPS analysis of CHCM, the oil–water separation mechanism is due to the large number of super-hydrophilic groups on its surface. This simple, green, and efficient method overcomes an important barrier to the safe separation of oil–water mixtures and provides insights into the design of advanced materials for practical oil–water separation.

A facile route for the fabrication of a superhydrophilic and underwater superoleophobic phosphorylated PVA-coated mesh for both oil/water immiscible mixture and emulsion separation

Special wettable materials have been shown to be promising for use in oil-water separation and, in particular, hydrogel-based materials have been studied for water separation from oil-water mixtures due to their high hydrophilicity. Here, a superhydrophilic and underwater superoleophobic phosphorylated PVA (PPVA) hydrogel-coated stainless-steel mesh with underwater oil repellency was prepared using a simple and facile route that introduced metal ions for PVA crosslinking. The PPVA hydrogel-coated mesh can not only separate immiscible oil-water mixtures but also separate surfactant-stabilized oil-in-water emulsions with a high separation efficiency (>99.2%). In addition, due to its multiple crosslinked networks, the resultant PPVA hydrogel-coated mesh exhibited good chemical stability and wear resistance and can tolerate high acid, alkali, salty and organic solvents.

Polyanionic Hydrogels as Reservoirs for Polycationic Antibiotic Substitutes Providing Prolonged Antibacterial Activity.

Implantation of biomedical devices is often followed by bacterial infections that may seriously affect implant functionalities and lead to their failure. In the context of bacterial resistance to antibiotics, which is a growing problem worldwide, new strategies that are able to overcome these problems are needed. In this work, we introduce a new formulation of hyaluronic acid (HA)-based antimicrobial material: HA hydrogels loaded with polyarginine (PAR), a polycationic antibiotic substitute. The loading is possible through electrostatic interactions between negatively charged HA and positively charged PAR. Such hydrogels absorb high quantities of PAR, which are then gradually released from the hydrogel. This original system provides a long-lasting antibacterial effect on an in vitro model of repetitive infection, thus demonstrating a strong potential to fight multiple rounds of infections that are resistant to antibiotic treatment. In addition, HA-PAR hydrogels could be deposited onto/into medical devices such as wound dressings and mesh prostheses used in clinical applications. Finally, we performed first in vivo tests of hydrogel-coated mesh materials to verify their biocompatibility in a rat model, which show no difference between control HA hydrogel and PAR-loaded hydrogel in terms of inflammation.

Durable, cost-effective and superhydrophilic chitosan-alginate hydrogel-coated mesh for efficient oil/water separation

Hydrogels with low-adhesive superoleophobicity are ideal candidates for modifying filtration substrates to achieve efficient and antifouling oil/water separation. However, there are still some unfavorable factors hindering their practical application, including expensive raw materials, complex fabrication process, poor stability and durability. In this work, a durable, cost-effective and superhydrophilic chitosan-alginate (CS-ALG) hydrogel coated mesh was developed by a facile, two-step dip-coating method for efficient oil/water separation in hypersaline environments. By integrating polysaccharide-based superhydrophobic surfaces and the hierarchical micro-/nanostructures, the as-fabricated CS-ALG hydrogel coated mesh exhibits excellent underwater superoleophobicity and anti-oil-fouling performance. Benefiting from that, the mesh could separate various oil/water mixtures with high separation efficiency (> 99%). It is worth mentioning that the double-cross-linked CS-ALG hydrogel based on sequential electrostatic interaction and ionic cross-linking shows excellent durability in hypersaline environments. All these attractive advantages make the hydrogel-coated mesh a promising candidate for oily wastewater treatment and oil spill cleanup.

Corrosive environments tolerant, ductile and self-healing hydrogel for highly efficient oil/water separation

Constructing high-performance materials that combine high separation efficiency, corrosive environments tolerance and self-healing ability are highly attractive for the next generation oil/water separation materials, but it is still a grand challenge. Here, we report a supramolecular hydrogel network of acrylamide and acrylic acid copolymers (P (AM-co-AA)) and chitosan (CS), sequentially cross-linked by amino-functionalized silica (APTES-SiO2) nanoparticles. The as-prepared APTES-SiO2/P (AM-co-AA)/CS composite hydrogels demonstrate outstanding ductility up to 1360% elongation, and good self-healing ability, combined with excellent under-water superoleophobicity with an oil contact angle above 164°. Most importantly, the underwater superoleophobic properties can be well maintained in various extremely harsh environments, such as acid, alkali and salt solution, providing great potential for oil/water separation in these corrosive environments. Indeed, the hydrogel-coated mesh displays oil/water selectivity above 98.7% at higher water flux.

Reusable, salt-tolerant and superhydrophilic cellulose hydrogel-coated mesh for efficient gravity-driven oil/water separation

Oil/water separation has been realized by various materials with special wettability, but most of them require complex instrumentation or involve toxic orcorrosive chemicals which may cause potential high cost and environmental concerns. In this work, a superhydrophilic and underwater superoleophobic cellulose hydrogel-coated mesh was fabricated through a simple and green process with the raw materials being low in cost and environmentally benign. The resulting mesh could separate different oil/water mixtures with a separation efficiency higher than 98.9% and a permeate flux up to 12,885 L m−2 h−1 solely driven by gravity. Importantly, this mesh still maintained a separation efficiency >98.2% even after 60 cycles of separation, suggesting its excellent stability for a long term application. Impressively, the mesh also exhibited great anti-salt properties. It was capable to separate saturated NaCl aqueous solutions from their oil (hexane) mixtures with a high separation efficiency. And even immersed in saturated NaCl for 12 h or subjected to sonication treatment, the mesh did not show any worsening in separation properties. These distinct advantages together with the high potential for scale-up production make the mesh very promising toward cost-effective oil/water separation in real-world practice.

Bioinspired Hydrogel-Coated Mesh with Superhydrophilicity and Underwater Superoleophobicity for Efficient and Ultrafast Oil/Water Separation in Harsh Environments

Microstructured calcium alginate (Ca-Alg) hydrogel exhibiting superhydrophilicity and underwater superoleophobicity is prepared for high speed and highly efficient oil/water separation. The fabricated mesh works in highly acidic or basic, salty, and high-temperature environments because of the stability of Ca-Alg. Moreover, nonwoven fabric used as a template for Ca-Alg is capable of separation of an oil-in-water emulsion.

A Novel Superhydrophilic and Underwater Superoleophobic Hydrogel‐Coated Mesh for Oil/Water Separation

A novel superhydrophilic and underwater superoleophobic polyacrylamide (PAM) hydrogel-coated mesh is successfully fabricated in an oil/water/solid three-phase system. Compared to traditional oleophilic materials, the as-prepared hydrogel-coated meshes can selectively separate water from oil/water mixtures with the advantages of high efficiency, resistance to oil fouling, and easy recyclability.