Excellent Water Absorption Research Articles

Research on Crack Sealing Performance of Polymer Microsphere/Hydrogel Composite System

Owing to their excellent water-absorption and swelling properties, polymer microspheres have been extensively applied as deep profile control agents in oilfields. These microspheres effectively seal large pore-throat channels in reservoirs, optimizing the water-absorption profile. In this study, a composite system was developed, comprising polymer microspheres and polyacrylamide polymers, with the inclusion of a cross-linking agent. The system leverages the synergistic effects of polymer microspheres and other plugging techniques to efficiently seal fractured reservoirs. Results indicate that the composite system exhibits strong blocking and scour resistance due to enhanced network integrity, higher viscosity, and improved elastic strength. Additionally, the composite system demonstrates a notable self-repairing capability, maintaining a high sealing efficiency even after a waterflood breakthrough.

Preparation and performance comparison of low‐dielectric epoxy resins cured by naphthalene‐ and phenyl‐based active esters

AbstractThe poor dielectric properties of epoxy resins limit their application in microelectronics, and active ester curing agent is an effective means to enhance the dielectric properties of epoxy resins. However, the phenyl active ester curing resins nowadays have the problem of low mechanical properties. In this work, a novel naphthalene‐based active ester‐cured resveratrol epoxy resin system (REP/NDA) was prepared for the first time. Compared with the phenyl‐active ester‐cured epoxy resin (REP/PDA), the naphthyl‐active ester prepared epoxy resin has obvious advantages in mechanical properties. The experimental results indicated a tensile strength measurement for REP/NDA at 91.9 MPa, the tensile strength of REP/PDA was 65.3 MPa, and the tensile strength of REP/NDA was 141% of that of REP/PDA. The prepared REP/NDA epoxy resin exhibits favorable dielectric properties, evidenced by a dielectric constant of 3.02 at 10 MHz and a dielectric loss of 0.0042, very good thermal stability (T5% of 379°C), excellent water absorption (only 0.49% for 7 days from 2 to 8°C) and good dimensional stability (coefficient of thermal expansion below Tg of 77 ppm). The first synthesis of naphthalene‐based active ester curing agent offers a reference for creating new low dielectric epoxy resin materials that work out exceptionally.

Adsorption behavior and mechanism of lead by starch/tobermorite composite hydrogel.

Tobermorite (TOB) is a synthetic inorganic mineral material with a montmorillonite-like layered structure that removes heavy metals from water, and its incorporation into starch-based hydrogels can optimize the stability and adsorption properties of the hydrogels; it can also significantly reduce the storage pressure of fly ash (FA) and reduce environmental pollution. This study utilized starch/tobemolite/acrylic acid (LR/TOB/AA) as the raw material, successfully synthesizing a starch-tobemolite composite hydrogel (LR-TOB/AA) using aqueous solution polymerization. The hydrogel exhibits excellent water absorption and retention capabilities, as well as a significant adsorption effect on Pb(II). The influence of adsorption duration, starting concentration, temperature, and hydrogel incorporation on Pb(II) adsorption was examined by intermittent adsorption experiments. The maximal adsorption capacity of Pb(II) was 900.25 mg/g, surpassing the majority of reported hydrogel adsorbents, as determined by Langmuir isothermal adsorption model fitting. Following five adsorption-desorption cycles, the hydrogel's adsorption of Pb(II) persisted above 90 %.

Enhancement and mechanism of mechanical properties and functionalities of polyacrylamide/polyacrylic acid hydrogels by 1D and 2D nanocarbon

Highly flexible hydrogels are widely used in fields such as agriculture, drug delivery, and tissue engineering. However, the simultaneous integration of excellent mechanical properties, swelling properties, and high electrical conductivity into a hydrogel is still a great challenge. This work introduces 1D tubular multi-walled carbon nanotubes (MWCNTs) and 2D layered graphene oxide (GO) into polyacrylamide/poly-acrylic acid (PAM/PAA) hydrogels. The high specific surface area and oxygen-containing groups of GO contribute to excellent mechanical properties and water absorption of the PAM/PAA hydrogels, but the conductivity is poorly affected due to the presence of defects on GO surface. However, MWCNTs with large aspect ratios benefit to form continuous conductive paths in PAM/PAA hydrogels which further improves conductivity of the hydrogels. MWCNTs are entangled with PAM/PAA molecular chains to form a dense three-dimensional (3D) network structure, and this special structure improves the water absorption of PAM/PAA hydrogels by 3.7 g g−1. What’s more, the MWCNTs/PAM/PAA hydrogel not only provides excellent mechanical properties (compressive strength up to 2.7 MPa), but also has high conductivity (2.3 S m−1). In particular, a strain sensor based on MWCNTs/PAM/PAA hydrogel exhibits exceptional sensitivity (gauge factor = 3.9 at 230–300 % strain) with a rapid response (200 ms) over a wide strain range (50 ∼ 200 %) which enables the ability to precisely and reliably monitor human motion. Therefore, the work provides a new insight into the design of multifunctional hydrogels with application on anatomical water plugging, electronic skin, and biosensors.

α-Amylase and polydopamine@polypyrrole-based hydrogel microneedles promote wound healing by eliminating bacterial infection

In this paper, we designed a novel “Freeze-thaw” type hydrogel microneedle (PP-CDLut-AMY MN). The “Freeze-thaw” cycle endows the MN excellent water absorption, with a dissolution rate of up to 486 %. The addition of polydopamine@polypyrrole (PP) enabled the MN to have a stable temperature increase to approximately 50 °C under near-infrared light irradiation, which exhibited killing rates of 99 % and 98 % against free S. aureus and E. coli, respectively. Natural macromolecule α-Amylase (AMY) was used as a bacterial biofilm disintegrator, and the destruction rate of S. aureus biofilm reached 83.2 %. Meanwhile, the incorporation of Hydroxypropyl-β-cyclodextrin @Luteolin (CDLut) provided the MN with good antioxidant properties, which could scavenge 73.35 % of DPPH free radicals. In vivo experiments have shown that the MN can effectively promote the healing of wounds infected by S. aureus biofilm and that the stable and gentle photothermal effect did not cause unnecessary damage to the surrounding tissues. We believe that this novel hydrogel MN has great potential to combat bacterial biofilms associated with wound infections.

Optimization of mechanical properties of small diameter artificial blood vessels based on alginate/chitosan/gelatin

Due to the rise in cardiovascular disease and the problem of autologous transplant limitation, the emergence of 3D bioprinted blood vessels using natural polymer materials as ink is becoming increasingly important in the field of small-diameter artificial blood vessels (φ ≤ 6 mm). In this paper, gelatin was firstly adopted to explore alginate/chitosan composite hydrogel properties and solve the current issues of poor mechanical performance and suboptimal printability of small-diameter blood vessels, which indicated that the modification caused a 17.7 % increase in compressive strength and a 63.2 % enhancement in tensile properties. The material microstructure evaluation showed that the samples with gelatin(4 %) presented the excellent water absorption rate(>90 %) significantly increasing their porosities. A self-developed 3D bioprinter was utilized to clarify the controllable mechanism of small-diameter artificial blood vessel, which has superior performance and excellent printability. This study provides a new reference solution to the current challenges in the bio-ink performance and printability of small-diameter artificial blood vessels.

Ultrasonic spraying quercetin chitosan nonwovens with antibacterial and deodorizing properties for sanitary napkin

With economic and social development, there is a growing focus on menstrual hygiene, and traditional sanitary napkins are no longer sufficient to meet women's needs. In this study, quercetin (QC) was efficiently and uniformly ultrasonic sprayed on thermally bonded chitosan nonwovens (CS) to prepare a multifunctional surface layer of sanitary napkins (QCX@CS). CS sprayed with 3 layers of QC (QC3@CS) exhibits excellent mechanical properties and high antibacterial rates against Escherichia coli (99.51 %) and Staphylococcus aureus (99.87 %), respectively. Besides, QC3@CS demonstrates strong free radical scavenging abilities, which have great potential to reduce the effects of reactive oxygen species on immune and metabolic functions during menstruation. QC3@CS demonstrates strong deodorizing abilities, with rates of 87.22 % for acetic acid and 90.88 % for ammonia, which could effectively eliminate the unpleasant odor associated with menstruation. Moreover, QC3@CS ensures excellent water absorption, anti-return properties, and cytocompatibility. This study may provide valuable insights into developing functional sanitary napkin materials based on natural extracts.

Endogenous electric field coupling Mxene sponge for diabetic wound management: haemostatic, antibacterial, and healing

Improper management of diabetic wound effusion and disruption of the endogenous electric field can lead to passive healing of damaged tissue, affecting the process of tissue cascade repair. This study developed an extracellular matrix sponge scaffold (K1P6@Mxene) by incorporating Mxene into an acellular dermal stroma-hydroxypropyl chitosan interpenetrating network structure. This scaffold is designed to couple with the endogenous electric field and promote precise tissue remodelling in diabetic wounds. The fibrous structure of the sponge closely resembles that of a natural extracellular matrix, providing a conducive microenvironment for cells to adhere grow, and exchange oxygen. Additionally, the inclusion of Mxene enhances antibacterial activity(98.89%) and electrical conductivity within the scaffold. Simultaneously, K1P6@Mxene exhibits excellent water absorption (39 times) and porosity (91%). It actively interacts with the endogenous electric field to guide cell migration and growth on the wound surface upon absorbing wound exudate. In in vivo experiments, the K1P6@Mxene sponge reduced the inflammatory response in diabetic wounds, increased collagen deposition and arrangement, promoted microvascular regeneration, Facilitate expedited re-epithelialization of wounds, minimize scar formation, and accelerate the healing process of diabetic wounds by 7 days. Therefore, this extracellular matrix sponge scaffold, combined with an endogenous electric field, presents an appealing approach for the comprehensive repair of diabetic wounds.

Preparation and characterization of starch carbamate modified natural sodium alginate composite hydrogel blend formulation and its application for slow-release fertilizer

The exploration of environmentally friendly slow-release fertilizer (SRF) based on natural bio-polymers is of great importance in the development of modern agriculture and horticulture. Herein, a novel starch carbamate (SC) modified sodium alginate (SA) hydrogel (SC/SAH) was prepared utilizing as-synthesized SC and natural SA through the cationic ions crosslinking method and ultimately the corresponding slow-release fertilizer (SC/SAH-SRF) was successfully developed by immersing the dried SC/SAH matrix into saturated urea solution. Due to the low gelation temperature and high viscosity of the synthesized SC, the formed SC/SAH exhibits significantly enhanced properties including excellent water absorbency up to 8.02 g/g with considerable repeatability, abundant pore structure and high hydrophilicity compared with the neat SAH and natural starch based hydrogel (NS/SAH). Accordingly, the SC/SAH leads to higher urea loading amount ∼ 1.28 g/g. Importantly, the resultant SC/SAH-SRF also shows superior slow-release performance, yielding a cumulative urea release of only 61.6 % within 10 h and almost completely release >16 h in water, what's more, only 58.5 % of the urea releases within 25 days and exceeding 50 days for complete release in soil column assays. The slow-release of urea from SC/SAH-SRF well complies for the first-order kinetics and accomplishes via a non-Fickian diffusion process. Moreover, the pot experiment demonstrates that the SC/SAH-SRF has higher growth promotion role for the maize seedlings than those of others. Consequently, this work provides a novel strategy for preparing environmentally friendly SRF by blending modified starch and hydrogel.

A shape memory cationized chitosan sponge loaded with thrombin for high-effective hemostasis and antibacterial activity

This study presents a thrombin-loaded cationized chitosan (TCCS) sponge with highly effective hemostatic and antibacterial activity. The TCCS sponge, prepared using a multistep method, features a porous structure, favorable mechanical properties, excellent water absorption ability, and shape recovery triggered by water or blood. The TCCS sponge exhibited strong antibacterial activity against Methicillin-resistant Staphylococcus aureus and Escherichia coli. Additionally, it demonstrated enhanced procoagulant and hemostatic efficacy in rat tail amputation and rat liver perforation wound models compared to commercial hemostats. Furthermore, the sponge exhibited favorable biocompatibility and biosafety. These findings suggest that the TCCS sponge has substantial potential for practical applications in managing severe hemorrhages and bacterial infections.

Gelatin/Dopamine/Zinc-Doped Ceria/Curcumin nanocomposite hydrogels for repair of chronic refractory wounds

Chronic wound healing is a common clinical challenge, characterized by bacterial infection, protracted inflammatory response, oxidative stress, and insufficient neovascularization. Nanozymes have emerged as a promising solution for treating skin wounds due to their antioxidant, antibacterial, and angiogenic properties. In recent years, combining nanozymes with hydrogels to jointly promote wound healing has attracted increasing research interest. However, most of the current nanocomposite hydrogels are still not effective in simultaneously controlling inflammatory, oxidative stress and bacterial invasion in wound healing. Improving the therapeutic functional diversity and efficacy of nanocomposite hydrogels remains a problem that needs to be addressed. In this study, we prepared nanocomposite hydrogels (GelMD-Cur@ZHMCe) by combining methylacrylated gelatin modified with dopamine (GelMD) with Zinc-doped hollow mesoporous cerium oxide nanoparticles loaded with curcumin (Cur@ZHMCe). The resulting hydrogels exhibited excellent water absorption, adhesion, and biocompatibility. In vitro and in vivo studies have demonstrated that GelMD-Cur@ZHMCe has excellent antioxidant, antibacterial, anti-inflammatory and vasculature-promoting properties, which enable it to rapidly promote wound repair. The wound healing rate of the rat total skin defect infection model treated with GelMD-Cur@ZHMCe reached 98.5±4.9 % after 14 days of treatment. It was demonstrated that this multifunctional nanocomposite hydrogel provides a promising therapeutic strategy for skin repair.

A 3D-printed acinar-mimetic silk fibroin-collagen-astragalus polysaccharide scaffold for tissue reconstruction and functional repair of damaged parotid glands

Salivary glands are the principal organs responsible for secreting saliva in the oral cavity. Tumors, trauma, inflammation, and other factors can cause functional or structural damage to the glands, leading to reduced saliva secretion. In this study, we innovatively prepared a acinar-mimetic silk fibroin-collagen-astragalus polysaccharide (SCA) scaffold using low-temperature three-dimensional (3D) printing and freeze-drying techniques. We evaluated the material properties and cell compatibility of the scaffold in vitro and implanted it into the damaged parotid glands (PG) of rats to assess its efficacy in tissue reconstruction and functional repair. The results demonstrated that the SCA scaffold featured a porous structure resembling natural acini, providing an environment conducive to cell growth and orderly aggregation. It exhibited excellent porosity, water absorption, mechanical properties, and biocompatibility, fulfilling the requirements for tissue engineering scaffolds. In vitro, the scaffold facilitated adhesion, proliferation, orderly polarization, and spherical aggregation of PG cells. In vivo, the SCA scaffold effectively recruited GECs locally, forming gland-like acinar structures that matured gradually, promoting the regeneration of damaged PGs. The SCA scaffold developed in this study supports tissue reconstruction and functional repair of damaged PGs, making it a promising implant material for salivary gland regeneration.

Stepwise co-assembled biomimetic hydrogel with antibacterial, angiogenesis, and tissue regeneration acceleration for diabetic wound healing

Bacterial infections and inadequate tissue regeneration capacity are prevalent issues in diabetic wounds, impeding the healing process. To solve these problems, a biomimetic hydrogel combined with bacterial cellulose (BC), recombinant human collagen type III (RHC), and ε-poly-L-Lysine (EPL) is fabricated by stepwise co-assembly technology. Owing to the RHC and EPL modifications of BC, the biomimetic hydrogel exhibited antibacterial effects and promoted fibroblast proliferation and angiogenesis, which accelerated the healing of diabetic wounds. Biomimetic hydrogels exhibit good mechanical properties and excellent water absorption, that can protect wounds and provide a moist environment. In addition, in vitro studies have shown that the hydrogels exhibit excellent antibacterial activity and biocompatibility. In vivo studies on diabetic wound healing have shown that biomimetic hydrogels can promote angiogenesis, accelerate collagen deposition, and re-epithelialize wound sites to promote wound healing. This study provides a new and promising strategy for the treatment of diabetic wounds.

Green Synthesis of Polyurethane Sponge-Grafted Calcium Alginate with Carbon Ink Aerogel with High Water Vapor Harvesting Capacity for Solar-Driven All-Weather Atmospheric Water Harvesting.

Atmospheric water harvesting (AWH) technology is a new strategy for alleviating freshwater scarcity. Adsorbent materials with high hygroscopicity and high photothermal conversion efficiency are the key to AWH technology. Hence, in this study, a simple and large-scale preparation for a hygroscopic compound of polyurethane (PU) sponge-grafted calcium alginate (CA) with carbon ink (SCAC) was developed. The PU sponge in the SCAC aerogel acts as a substrate, CA as a moisture adsorber, and carbon ink as a light adsorber. The SCAC aerogel exhibits excellent water absorption of 0.555-1.40 g·g-1 within a wide range of relative humidity (40-80%) at 25 °C. The SCAC aerogel could release adsorbed water driven by solar energy, and more than 92.17% of the adsorbed water could be rapidly released over a wide solar intensity range of 1.0-2.0 sun. In an outdoor experiment, 57.517 g of SCAC was able to collect 32.8 g of clean water in 6 h, and the water quality meets the drinking water standards set by the World Health Organization. This study suggests a new approach to design promising AWH materials and infers the potential practical application of SCAC aerogel-based adsorbents.

A novel biological antibacterial polyvinyl alcohol/polyionic liquid hydrogel for wound dressing.

The release of antibiotics or anions by traditional bacteriostatic agents led to the development of bacterial drug resistance and environmental pollution. Ionic liquids (ILs) have become important choices for antibacterial agents because of their excellent physical, chemical and biological properties. In this paper, the bioactivities of 1-vinyl-3-butylimidazolium chloride ([VBIM]Cl, IL) and poly (1-vinyl-3-butylimidazolium chloride) (P[VBIM]Cl, PIL) were evaluated, and the potential antibacterial material was used to synthesize hydrogels. Using the colony formation assay and the Oxford cup method, antibacterial effect of IL and PIL were tested. Cell-Counting-Kit-8 (CCK-8) experiments were used to study the IC50 (half maximal inhibitory concentration) values of IL and showed 1.47mg/mL, 0.35mg/mL and 0.33mg/mL at 24 h, 48 h and 72 h, respectively. The IC50 value of PIL were 12.15μg/mL, 12.06μg/mL and 11.76μg/mL at 24 h, 48 h and 72 h, respectively. The PIL is further crosslinked with polyvinyl alcohol (PVA) to form a novel hydrogel through freeze-thaw cycles. The newly fabricated hydrogel exhibited a high water content, excellent water absorption properties and outstanding mechanical performance. Using the colony formation assay and the inhibition zone assay, the hydrogels exhibited favorable antibacterial effects (against E.coli and S.aureus) such that nearly 100% of the bacteria were killed in liquid medium while cultivating with H4 (synthesized by 0.5g PIL and 1g PVA). In addition, the cytotoxicity of PIL was significantly reduced through hydrogen bond crosslinking. H4 showed the highest antibacterial activity and a good biocompatibility. The results indicated that the PVA&PIL hydrogels had great potential for wound dressing.

Investigation on the Tea Polyphenol/Swelling Gels to Inhibit Coal Spontaneous Combustion: An Experimental Study

ABSTRACT Developing new fire-fighting material is most significant for effective prevention and control of coal spontaneous combustion. To enhance the flame-retardant performance of the gel, the tea polyphenol/swelling gels are developed using a water-soluble polymerization method. Thermogravimetric analysis, programmed temperature experiments, and Fourier-transform infrared spectroscopy are used to reveal the structural characteristics, microscopic morphology, and thermal stability of the gel. Experimental testing the tea polyphenol/swelling gels’ water absorption, water retention, and reusability as well as their inhibitory effect on coal spontaneous combustion. The results showed that the prepared tea polyphenol/swelling gels exhibited a porous three-dimensional network structure, with a maximum swelling ratio of 607.2 g/g and a salt absorption rate of 121.4 g/g. After the testing coal sample is treating by the tea polyphenol/swelling gels, its CO production rate is sharply decreased, but the corresponding ignition point temperature and flame-retardant rate are significantly increased. The activation energy in the first stage is increased by 32.2 kJ·mol−1, in the second stage by 4.0 kJ·mol−1, and in the third stage by 23.2 kJ·mol−1. Additionally, the active functional groups such as hydroxyl and methyl in the coal are also reduced by the treatment of tea polyphenol/swelling gels. Correlation analysis indicate that the inhibition effect of coal spontaneous combustion can be achieved by reducing -OH, CH3/CH2 groups, while the increasing of C = C, C- O, C- H functional groups in the coal. Moreover, the tea polyphenol/swelling gels performing the characteristics of excellent water absorption, inhibiting coal spontaneous combustion by absorbing heat, covering the coal microstructure, and inhibiting the oxidative activity of coal molecules. This study can provide theoretical guidance for the application of swelling gels in inhibiting coal spontaneous combustion.

Coal gasification slag for preparation of environmentally friendly superabsorbent composites with rapid water absorption and salt tolerance

It is crucial to design the novel low-cost and salt-tolerant superabsorbent for safeguarding food security and achieving sustainable agriculture. Herein, the porous superabsorbent composites with excellent salt tolerance were fabricated by redox-initiated grafting polymerization using water-based Pickering foam template co-stabilized with solid waste of coal gasification slag and plant particles Sapindus mukorossi pericarp. The stabilization mechanism of Pickering foams, swelling performance and salt-resistance of porous superabsorbent composites were studied in detail. Due to the abundant porous structure and the presence of coal gasification slag, the obtained superabsorbent composites exhibited rapid swelling rate and excellent water absorption capability, and the maximum water absorption in distilled water and 0.9 wt% NaCl solution reached 910 g/g and 126 g/g after 30 min, respectively. As 1.5 wt% the optimal superabsorbent composites was added into the saline-alkali soil, the growth of cabbages was significantly improved, and the plant height and chlorophyll content increased by 45.0% and 12.5%, respectively. This work served as a significant reference for preparing novel environmentally friendly water-saving materials for arid saline-alkali soil improvement.

All-in-one hydrogel patches with sprayed bFGF-loaded GelMA microspheres for infected wound healing studies

The current wound healing process faces numerous challenges such as bacterial infection, inflammation and oxidative stress. However, wound dressings used to promote wound healing, are not well suited to meet the clinical needs. Hyaluronic acid (HA) not only has excellent water absorption and good biocompatibility but facilitates cell function and tissue regeneration. Dopamine, on the other hand, increases the overall viscosity of the hydrogel and possesses antioxidant property. Furthermore, chitosan exhibits outstanding performance in antimicrobial, anti-inflammatory and antioxidant activities. Basic fibroblast growth factor (bFGF) is conducive to cell proliferation and migration, vascular regeneration and wound healing. Hence, we designed an all-in-one hydrogel patch containing dopamine and chitosan framed by hyaluronic acid (HDC) with sprayed gelatin methacryloyl (GelMA) microspheres loaded with bFGF (HDC-bFGF). The hydrogel patch exhibits excellent adhesive, anti-inflammatory, antioxidant and antibacterial properties. In vitro experiments, the HDC-bFGF hydrogel patch not only showed significant inhibitory effect on RAW cell inflammation and Staphylococcus aureus (S. aureus) growth but also effectively scavenged free radicals, in addition to promoting the migration of 3 T3 cells. In the mice acute infected wound model, the HDC-bFGF hydrogel patch adhered to the wound surface greatly accelerated the healing process via its anti-inflammatory and antioxidant activities, bacterial inhibition and pro-vascularization effects. Therefore, the multifunctional HDC-bFGF hydrogel patch holds great promise for clinical application.

Polyhedral Oligomeric Sesquioxane Cross-Linked Chitosan-Based Multi-Effective Aerogel Preparation and Its Water-Driven Recovery Mechanism.

The use of environmentally friendly and non-toxic biomass-based interfacial solar water evaporators has been widely reported as a method for water purification in recent years. However, the poor stability of the water transport layer made from biomass materials and its susceptibility to deformation when exposed to harsh environments limit its practical application. To address this issue, water-driven recovery aerogel (PCS) was prepared by cross-linking epoxy-based polyhedral oligomeric silsesquioxane (EP-POSS) epoxy groups with chitosan (CS) amino groups. The results demonstrate that PCS exhibits excellent water-driven recovery performance, regaining its original volume within a very short time (1.9 s) after strong compression (ε > 80%). Moreover, PCS has a water absorption rate of 2.67 mm s-1 and exhibits an excellent water absorption capacity of 22.09 g g-1 even after ten cycles of absorption-removal. Furthermore, a photothermal evaporator (PCH) was prepared by loading the top layer with hydrothermally reacted tannins (HAs) and Zn2+ complexes. The results indicate that PCH achieves an impressive evaporation rate of 1.89 kg m-2 h-1 under one sun illumination. Additionally, due to the antimicrobial properties of Zn2+, PCH shows inhibitory effects against Staphylococcus aureus and Escherichia coli, thereby extending the application of solar water evaporators to include antimicrobial purification in natural waters.

An Innovative High-Strength Double-Network Hydrogel for Use as a Drilling Fluid Plugging Agent.

The problem of wellbore leakage is a key challenge in the petroleum industry, limiting drilling progress and increasing drilling costs. Plugging agents play a role in repairing leaks and fractures; however, traditional plugging materials generally have low mechanical strength, poor adaptability to permeable strata, limited water absorption and expansion capabilities, and poor temperature and salt resistance. To address these limitations, a pioneering polyacrylic acid-polyacrylamide (PAA/PAM) double-network hydrogel was synthesized through aqueous solution polymerization in this study. Its strength, water absorption, expansion, temperature resistance, salt resistance, and plugging effectiveness were comprehensively evaluated. The results demonstrate that good mechanical performance is exhibited by the synthesized hydrogel, capable of withstanding a maximum stress of approximately 3.5 MPa at a 90% strain. Excellent water absorption and expansion are observed in the synthesized double-network hydrogel, with a maximum expansion of 6 times within 30 min and 8 times after 2 h. Test results show that the hydrogel had good temperature resistance and salt resistance, maintaining a strength grade E within the experimental range. The simulated evaluation of the plugging experiment indicates that, under conditions of 130 °C and 6 MPa, the leakage rate of the drilling fluid is maintained below 5 mL/min when the double-network hydrogel is utilized. From the above experimental results, it can be illustrated that excellent mechanical properties, impressive water absorption, and expansion capabilities are exhibited by the synthesized double-network hydrogel. Furthermore, the high-temperature resistance and salt resistance of the double-network hydrogel were also demonstrated. Therefore, In comparison to traditional plugging materials, significant promise is held by this newly synthesized double-network hydrogel material as a plugging agent in drilling fluids.