Cross-linking Method Research Articles

Structure and thermal properties of acrylic copolymer gels: effect of composition and cross-linking method

Two approaches to the synthesis of hydrogels based on polyacrylamide (pAAm) with copolymers were compared in the paper—traditional chemical cross-linking and physical cross-linking with montmorillonite (MMT). The main aim of the work was to find an adequate replacement of the chemical toxic cross-linking agent MBAAm (N,N'-methylene-bis-acrylamide) by using non-toxic—natural clay MMT for synthesis of pAAm gels, which are planned to be used as soil conditioners. A series of hydrogels based on acrylic monomers (acrylamide (AAm), acrylonitrile (AN), acrylic acid (AA)) physically cross–linked by MMT and chemically cross-linked were synthesized. For the synthesized gels, the influence of the synthesis method on the formation of the structure and the mechanism of thermal destruction in the presence of air was analyzed using a set of physicochemical methods: FTIR, XRD, SEM, DSC and TG/DTG. According to FTIR and XRD data, pAAm-MMT and pAAm-AN-MMT samples formed an intercalated/exfoliated structure, whereas pAAm-AA-MMT had an intercalated structure. The endothermic reaction of decomposition of xerogels based on acrylic polymers with and without MMT was observed using DSC and derivative thermogravimetry analyses, coupled with measurement of FTIR spectra of volatile products of thermolysis. All studied composites were relatively thermoresistant, which had three distinct regions of phase transitions and their thermal decomposition occurred at a temperature range 310–465 °C.Graphical

Fabrication of a reusable Ti3C2Tx MXene/ZnO@zinc alginate hydrogel for highly efficient and selective phosphate removal

Nano-Zinc oxide (ZnO) shows great potential for phosphate adsorption, but its tendencies to aggregate and lack of selectivity significantly impact adsorption efficiency. The synthesis of Ti3C2Tx MXene/ZnO complexes efficiently disperses ZnO, thereby enhancing selectivity, while encountering challenges in recovery. In this study, Ti3C2Tx MXene/ZnO-embedded zinc crosslinked alginate hydrogel beads (MXZA) were synthesized by solution-phase and ionic cross-linking methods as a highly efficient, selective, and reusable phosphate adsorbent. MXZA exhibited a maximum adsorption capacity of up to 86.67 mg/g of phosphate, and showed excellent adsorption selectivity in complex solutions (e.g., Cl-, NO3–, and SO42-). In short, the MXZA gel adsorbent has a wide application perspective in the effective and selective removal of phosphate from wastewater.

Empowering PLA Bioplastics: Elevating applications horizon through groundbreaking Eco-Innovative Fibrillation, chain Extension, and crosslinking techniques

This comprehensive study introduces pioneering techniques in the toughening of polylactic acid (PLA) by incorporating thermoplastic polyurethane (TPU) nanofibrils, leveraging two distinct crosslinking methods to significantly enhance the material’s mechanical performance. Method 1 employs a silane/moisture crosslinking process, whereas Method 2 utilizes a tailored diisocyanate crosslinking approach, offering a more environmentally sustainable alternative. Molecular structural analysis was performed extensively by using X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1H NMR), gel permeation chromatography (GPC), rheological assessments, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). Method 2 not only preserves TPU nanofibrils but also elevates the mechanical properties of PLA-TPU composites beyond the capabilities of Method 1. Notably, by leveraging the simultaneous crosslinking of TPU and chain extension of PLA with the tailored diisocyanate approach, we enhance PLA’s mechanical properties and energy absorption capabilities. These advancements are achieved without a high rubber content, which typically compromises strength/stiffness, thermomechanical stability, crystallization, and transparency of PLA. The resulting composites prepared via Method 2 display remarkable increases in tensile toughness, ranging from 30-60 MPa, and impact strength, achieving a span of 60–140 J/m. This is primarily due to the occurrence of a brittle-to-ductile transition (BDT) at only 3 wt% nanofibril TPU content while maintaining a high PLA modulus of 3 GPa. This critical balance between chain-extending and crosslinking reactions ensures the maintenance of PLA’s inherent strength/stiffness, crystallization, and optical clarity. The research presented here marks a significant shift in the development of tougher, more thermally stable, transparent, and sustainable polymer blends and composites. Method 2, with its tailored fiber size reduction (90–280 nm), and environmental consciousness, broadens the horizon of PLA’s applications.

Dual-Temperature/pH-Sensitive Hydrogels with Excellent Strength and Toughness Crosslinked Using Three Crosslinking Methods.

Hydrogels are widely used as excellent drug carriers in the field of biomedicine. However, their application in medicine is limited by their poor mechanical properties and softness. To improve the mechanical properties of hydrogels, a novel triple-network amphiphilic hydrogel with three overlapping crosslinking methods using a one-pot free-radical polymerization was synthesized in this study. Temperature-sensitive and pH-sensitive monomers were incorporated into the hydrogel to confer stimulus responsiveness, making the hydrogel stimuli-responsive. The successful synthesis of the hydrogel was confirmed using techniques, such as proton nuclear magnetic resonance spectroscopy (1H NMR), Fourier-transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). In order to compare and analyze the properties of physically crosslinked hydrogels, physically-chemically double-crosslinked hydrogels, and physically-chemically clicked triple-crosslinked hydrogels, various tests were conducted on the gels' morphology, swelling behavior, thermal stability, mechanical properties, and drug loading capacity. The results indicate that the triple-crosslinked hydrogel maintains low swelling, high mechanical strength, and good thermal stability while not significantly compromising its drug delivery capability.

Immobilization of novel bifunctional polymer with amide and amidoxime groups in biochar-chitosan composite gels for enhancing uranium(VI) uptake

This work synthesized poly ethanolamine amidoxime modified winter melon and chitosan-derived biochar (PEA-CTS@WBC) using chemical crosslinking method for uranium(VI) removal. The factors influencing uranium(VI) adsorption by PEA-CTS@WBC, including pH, adsorbent dosage, time, temperature, and initial U(VI) concentration were explored. The material’s performance was characterized, and the underlying mechanism of U(VI) removal was analyzed using various techniques. The characterization results indicated that the PEA-CTS@WBC took on a membrane shape with numerous pores and wrinkles distributed on the surface, providing more active sites that can effectively promote the complexation and adsorption of U(VI). The results demonstrated that PEA-CTS@WBC effectively removed U(VI), achieving a maximum adsorption capacity of 485.89 mg/g at the pH of 5.0. The process suggested a dominant role for chemical adsorption. The Freundlich isotherm model demonstrated a high degree of alignment with the observed adsorption behavior, indicating a predominantly multilayer adsorption process. Thermodynamic studies indicated that adsorption was a spontaneous endothermic process. The XPS analysis demonstrated that the adsorption process was primarily due to the formation of stable complexes with NH3+-C(O), N–C, C–N, C=C, O–H and C=O. This research showed that the introduction of amide and amidoxime groups significantly improved the adsorption effect of biochar-chitosan gels on U(VI). PEA-CTS@WBC had a high selective adsorption characteristics and good reusability for U(VI) in aqueous solutions. PEA-CTS@WBC was an economical, efficient and stable composite material. These findings provided a theoretical basis for the treatment of wastewater contaminated with U(VI).

Fibrin-like calcium release 3D gelatin fiber hemostatic scaffold for interventional surgery

Hemostasis plays a critical role in wound treatment and surgical operations. Blood coagulation can be facilitated by both physical coagulation, involving fibrin and platelets, and chemical coagulation, promoted by calcium ion release. In this study, we fabricated a 3D gelatin fiber and calcium-releasing gelatin sponge (GFGS) to promote the hemostatic process at the wound site. Fibrin-like gelatin fibers electrospun on an ethanol bath were able to form 2–5 µm fibers that maintained a 3D structure and did not dissolve in water. These fibers, which were not densely packed, created a porous space that could entangle with red blood cells, thereby expanding the binding sites. The uncrosslinked gelatin sponge undergoes dissolution upon contact with blood, facilitating blood infiltration and the localized release of calcium ions to enhance the coagulation process. The GFGS demonstrated excellent biocompatibility and hemostatic effects, reducing blood loss by five times compared to regular gauze in a 3 mm diameter wound. By modifying the collector of the electrospinning device and the crosslinking methods, we were able to create a scaffold where gelatin fibers do not adhere to each other and maintain a 3D structure. Additionally, by crosslinking the gelatin to release calcium ions, we were able to enhance the hemostatic effect. This is expected to rapidly prevent and treat wounds occurring after interventional surgeries.

Hydrogels loaded with MSC‐derived small extracellular vesicles: A novel cell‐free tissue engineering system for diabetic wound management

AbstractWith the aging and obesity era, the increasing incidence of diabetes and diabetic complications, especially the non‐healing wounds, imposes a serious economic burden on both patients and society. The complex microenvironments, including hyperglycemia, bacterial infection, ischemia, and nerve damage, lead to the prolonged inflammation and proliferation phase of diabetic wounds. Mesenchymal stem cell‐derived small extracellular vesicles (MSC‐sEVs), which contain a rich variety of therapeutic molecules, have been chased for decades because of their potential roles in cellular communication, tissue regeneration, and drug delivery. As powerful tools for the controlled‐sustained release of sEVs, biocompatible hydrogels have been applied in a wide range of biomedical applications. Herein, we first summarize the pathological features of diabetic wounds, such as angiopathy, neuropathy, and immune cell dysfunction. Then, we discuss the biological properties, therapeutic performance, and stability of pure MSC‐sEVs. After that, we discuss the components, application patterns, and responsiveness of hydrogels. Next, we discuss the loading avenues of MSC‐sEVs into hydrogel, the release behaviors of sEVs from hydrogels, and the influence of the crosslinking method on the hydrogel‐sEV composites. Finally, we provide an overview of the current applications of hydrogels loaded with MSC‐sEVs as a novel cell‐free tissue engineering system in managing diabetic wounds and propose the critical unsolved issues. This review is expected to provide meaningful guidance for developing a novel cell‐free tissue engineering system for diabetic wound management.

An Alternative Approach to Plastic Recycling: Fabrication and Characterization of rPET/CA Nanofiber Carriers to Enhance Porcine Pancreatic Lipase Stability Properties.

In response to the increasing demand for sustainable technologies, this study presents a novel approach to plastic recycling. In this study, a method was presented to produce nanofiber carriers by electrospinning using recycled poly(ethylene terephthalate) (rPET) obtained from wastewater bottles and cellulose acetate (CA). These carriers serve as a platform for immobilized porcine pancreatic lipase (PPL), aiming to enhance its stability. The production parameters for the rPET/CA nanofibers were found to be an rPET concentration of 15% (v/v), a CA concentration of 6% (v/v), an electrical voltage of 13 kV, a needle-collector distance of 18 cm, and an injection speed of 0.1 mL/h. The nanofiber structure and morphology were assessed by using attenuated total reflectance-infrared Fourier transform infrared (ATR-FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) analyses. Then, PPL was immobilized onto the nanofibers through adsorption and cross-linking methods. The optimum temperature for free PPL was determined to be 30 °C, and the optimum temperature for PPL immobilized on rPET/CA was determined to be 40 °C. It was observed that, especially under acidic conditions, after the immobilization process, PPL immobilized rPET/CA nanofibers became more resistant to pH changes than free PLL. Furthermore, the immobilized PPL exhibited improved pH stability, reusability, and thermal stability compared to its free counterpart. This innovative approach not only contributes to plastic waste reduction but also opens new avenues for enzyme immobilization with potential applications in biocatalysis and wastewater treatment.

Superwetting PVA/cellulose aerogel with asymmetric structure for oil/water separation and solar-driven seawater desalination

Extracting clean water from oily wastewater and seawater is one of the effective strategies to alleviate the freshwater crisis. However, achieving both high separation efficiency and excellent salt resistance remain challenges for materials. Herein, a novel methyltrichlorosilane-modified polyvinyl alcohol/cellulose aerogel (MPCA) was prepared by freeze drying, chemical cross-linking, and chemical vapor deposition (CVD) methods. The superwetting MPCA presented an asymmetric structure, in which the small dense pores at the top surface facilitated the efficient separation of water-in-oil (W/O) emulsions and the large pores on the bottom surface were beneficial for brine exchange. The as-prepared superwetting aerogel was suitable for the separation of various W/O emulsions with excellent separation flux (631.9–2368.7 L·m−2·h−1) and outstanding separation efficiency (99.5 %). In addition, MPCA achieved a high evaporation efficiency of 1.39 kg·m−2·h−1 and a satisfactory energy conversion efficiency of 89.7 %. Moreover, the unique asymmetric structure endowed the evaporator excellent salt resistance and could self-dissolve the accumulated salt in 20 min. The as-prepared MPCA could achieve efficient W/O emulsion separation as well as produce freshwater in seawater, providing a new strategy for oily waste seawater purification.

Development of cross-linked glucose oxidase integrated Cu-nanoflower electrode for reusable and stable glucose sensing

The demand for glucose-sensing devices has increased along with the increasing diabetic population. Here, we aimed to construct a system with a glucose oxidase (GOx)-integrated Cu-nanoflower (Cu-NF) as the underlying electrode. This novel system was successfully developed by creating a cross-linked GOx within a Cu-NF matrix, forming a c-GOx@Cu-NF-coated film on a carbon screen-printed electrode (CSPE). A comparison of the stabilities of the cross-linking methods demonstrated enhanced durability, with an activity level of >88 % maintained after approximately 35 days of storage in room temperature buffer. Regarding the ability of the c-GOx@Cu-NF modified CSPE to detect glucose via electrochemical methods, the redox potential gap (ΔE) and peak current increased in the presence of GOx. In comparison to that of glucose, the sensitivity of c-GOx@Cu-NF was approximately 8 times greater than that of GOx@Cu-NF, with a detection limit of 0.649 μM and a linear range of 5–500 μM. It sustained an average relative activity of 80 % over 20 days. After 10 cycles of repeated use, the activity remained above 75 %. In terms of evaluating the electrode's specificity for glucose, the detection rate for individual similar substances was approximately 1 %. The introduction of a crosslinking strategy to Cu-NF, leading to enhanced mechanical stability and conductivity, improved the detection capability. Furthermore, this approach led to increased long-term storage stability and reusability, allowing for specific glucose detection. To our knowledge, this report represents the first demonstration of a c-GOx@Cu-NF system for integrating electrochemical biosensing devices into digital healthcare pathways, offering enhanced sensing accuracy and mechanical stability.

Polyethyleneimine and chitosan incorporated winter melon-derived biochar composite gels for highly selective capture of uranium(VI)

This work synthesized polyethyleneimine and chitosan modified winter melon-derived biochar (PEI-CTS@WBC) using chemical crosslinking method for uranium(VI) removal. The factors influencing uranium(VI) adsorption by PEI-CTS@WBC, including pH, adsorbent dosage, time, temperature, and initial U(VI) concentration were explored. The material's performance was characterized, and the underlying mechanism of U(VI) removal was analyzed using various techniques. Compared with other reported adsorbents, the maximum adsorption capacity of PEI-CTS@WBC for U(VI) was 411.44 mg g−1, which was higher than most existing adsorbents. The dynamics studies showed that adsorption was more in line with the second-order kinetic model, indicating that chemical adsorption was the main process. The Kd and SU value of U(VI) by PEI-CTS@WBC could reach 11194.44 mL g−1 and 76.47 % respectively, which exhibited a high selective adsorption characteristics for U(VI) in aqueous solutions. The XPS analysis demonstrated that the adsorption process was primarily due to the formation of stable complexes with N-H, N-C, C-O and O-H. This research showed that the introduction of polyethyleneimine and chitosan greatly improved the adsorption effect of WBC on U(VI). PEI-CTS@WBC had high selective adsorption characteristics and good reusability for U(VI) in aqueous solutions. PEI-CTS@WBC was an economical, efficient and stable composite material. These findings provided a theoretical basis for the treatment of wastewater contaminated with U(VI).

Adsorption and estimation of As (III) from wastewater using cross linked Chitosan-STPP nanoparticles with voltammetric analysis computrace, isotherms, and kinetic study

Chitosan (CS) is a naturally occurring polycationic linear amino polysaccharide produced commonly through the deacetylation of chitin. This study describes the synthesis of Chitosan (CS) modified with sodium tripolyphosphate (STPP) using an efficient coated Cross-linked method. The study investigated the efficacy of chitosan-tripolyphosphate (CS-STPP) nanoparticles for the efficient adsorption of As (III) ions from a wastewater solution. The effect of initial Arsenic (III) ion concentration, solution pH, and temperature on adsorption efficiency was thoroughly investigated. The highest adsorption capacity of CS-STPP nano adsorbents for As (III) was found to be 39.8 mg/g and 39.6 mg/g, respectively, at pH 5.5, and a temperature of 30 °C. The FESEM, SEM, HRTEM, XRD, FTIR, DLS, and TGA results indicated that the adsorption process of As (III) was chemically dominating. As (III) Determine with the anodic linear sweep voltammetry 797 VA Computrace (Metrohm). The Langmuir parameters of 40.9 mg/g and 1000 L/mg were found for maximum adsorption capacity, which indicated monolayer adsorption on a homogeneous site, Freundlich isotherm is applicable for multilayer adsorption onto heterogeneous sites. The thermodynamic study showed that the adsorption of As (III) by CS-STPP was spontaneous, feasible, and exothermic at temperatures ranging from 30 °C to 50 °C. The kinetic model indicated that the adsorption processes persist well to the pseudo-second-order kinetics model. The reaction is suitable for a pseudo-second-order model, it indicates an inclination for chemisorption. Adsorption-desorption processes are determined efficiency of bio adsorbent by several physicochemical cycles. All results indicate that the prepared CS-STPP nanoparticles might be considered a cost-effective adsorbent for removing As (III) from wastewater.

Soft Actuators and Actuation: Design, Synthesis, and Applications.

Soft actuators are one of the most promising technological advancements with potential solutions to diverse fields' day-to-day challenges. Soft actuators derived from hydrogel materials possess unique features such as flexibility, responsiveness to stimuli, and intricate deformations, making them ideal for soft robotics, artificial muscles, and biomedical applications. This review provides an overview of material composition and design techniques for hydrogel actuators, exploring 3D printing, photopolymerization, cross-linking, and microfabrication methods for improved actuation. It examines applications of hydrogel actuators in biomedical, soft robotics, bioinspired systems, microfluidics, lab-on-a-chip devices, and environmental, and energy systems. Finally, it discusses challenges, opportunities, advancements, and regulatory aspects related to hydrogel actuators.

Vinyl-based in-situ crosslinked polybenzimidazoles for anion exchange membranes water electrolysis

In the present work, a series of crosslinked polybenzimidazole (PBI) anion exchange membranes (AEMs) were prepared via the vinyl-based in-situ crosslinking method. The crosslinked AEMs (PcPBI-x-C) had simultaneously improved dimensional stability, mechanical properties and chemical stability compared to the pre-crosslinked AEM (PcPBI). The effect of different crosslinker structures including rigid benzene ring, flexible alkanes and flexible alkanes containing hydrophilic imidazolium on the performance of AEMs was systematically investigated. As results, the swelling ratio of the PcPBI-Vbc-C membrane containing rigid benzene ring crosslinked structure was reduced by 49.8 % (from 22.1 % to 11.1 %), the tensile strength of PcPBI-Im-C membrane containing flexible hydrophilic imidazolium crosslinked structure increased by 33.5 % (from 48.1 MPa to 64.2 MPa) and the elongation at break by 115.2 % (from 28.9 % to 62.2 %). PcPBI-x-C crosslinked AEMs had conductivities of 87.6–98.7 mS/cm at 80 °C, their conductivity retentions were 72.5–82.4 % after immersion in 2 M KOH solution for 2400 h. Furthermore, the anion exchange membrane water electrolysis (AEMWE) with PcPBI-Im-C as AEM could be stably operated for 100 h at the current density of 200 mA/cm2, indicating that PBI AEMs containing flexible hydrophilic imidazolium crosslinked structure possess great potential for application in AEMWE.

Eco-Friendly Production of Polyvinyl Alcohol/Carboxymethyl Cellulose Wound Healing Dressing Containing Sericin.

Wound dressing production represents an important segment in the biomedical healthcare field, but finding a simple and eco-friendly method that combines a natural compound and a biocompatible dressing production for biomedical application is still a challenge. Therefore, the aim of this study is to develop wound healing dressings that are environmentally friendly, low cost, and easily produced, using natural agents and a physical crosslinking technique. Hydrogel wound healing dressings were prepared from polyvinyl alcohol/carboxymethyl cellulose and sericin using the freeze-thawing method as a crosslinking method. The morphological characterization was carried out by scanning electron microscopy (SEM), whereas the mechanical analysis was carried out by dynamic mechanical analysis (DMA) to test the tensile strength and compression properties. Then, the healing property of the wound dressing material was tested by in vitro and ex vivo tests. The results show a three-dimensional microporous structure with no cytotoxicity, excellent stretchability with compressive properties similar to those of human skin, and excellent healing properties. The proposed hydrogel dressing was tested in vitro with HaCaT keratinocytes and ex vivo with epidermal tissues, demonstrating an effective advantage on wound healing acceleration. Accordingly, this study was successful in developing wound healing dressings using natural agents and a simple and green crosslinking method.

Preparation and Rheological Properties of the PVA/CMC/Gel Composite for Mining.

A composite gel material with an interpenetrating network structure was formed using the chemical cross-linking method. The viscosity, yield stress, and thixotropy of a poly(vinyl alcohol)/carboxymethyl cellulose/gelatin (PVA/CMC/Gel) composite gel slurry with different ratios were tested using a viscometer, and the interaction between the surface of the gelling agent and the cross-linking agent was analyzed by calculating the frontline orbital energy of a single polymer material molecule. The seepage diffusion characteristics of the composite gel in a goaf were then studied through a numerical simulation. The results indicate that the PVA/CMC/Gel composite gel exhibits shear thinning behavior following the power law model and behaves as a pseudoplastic fluid. The optimal ratio for the composite gel at 30 °C is determined as follows: 30 wt % for the gelling agent (PVA/(Gel + CMC) = 20:10), 4 wt % for the cross-linking agent, 3.09 wt % for the carbide slag, 7.5 wt % for the alcohol amine solution, and 0.5% sodium dodecyl sulfonate + 0.1% alkyl glycoside for the foaming agent. Gel exhibits the lowest energy band gap (0.096 eV), indicating strong reaction activity and strong reaction with the cross-linking agent (sodium tetraborate). PVA has the largest energy band gap (0.238 eV), strong molecular stability, and weak reaction with the cross-linking agent (sodium tetraborate). When the dip angle of the goaf is 4° and the injection time is 40 min, the composite gel tends to diffuse more easily along the dip. The investigation into the rheological properties of the PVA/CMC/Gel composite gel holds significant importance in the design of coal mine pipeline transportation and understanding diffusion flow in goaf.

Preparation and Characterization of Silica-Coated Sodium Alginate Hydrogel Beads and the Delivery of Curcumin

In this study, to address the defects of sodium alginate (SA), such as its susceptibility to disintegration, silica was coated on the outer layer of sodium alginate hydrogel beads in order to improve its swelling and slow-release properties. Tetraethyl orthosilicate (TEOS) was used as the hydrolyzed precursor, and the solution of silica precursor was prepared by sol-gel reaction under acidic conditions. Then SA–silica hydrogel beads prepared by ionic crosslinking method were immersed into the SiO2 precursor solution to prepare SA–silica hydrogel beads. The chemical structure and morphology of the hydrogel beads were characterized by XRD, FTIR, and SEM, and the results showed that the surface of SA–silica beads was successfully encapsulated with the outer layer of SiO2, and the surface was smooth and dense. The swelling experiments showed that the swelling performance effectively decreased with the increase of TEOS molar concentration, and the maximum swelling ratio of the hydrogel beads decreased from 41.07 to 14.3, and the time to reach the maximum swelling ratio was prolonged from 4 h to 8 h. The sustained-release experiments showed that the SA–silica hydrogel beads possessed a good pH sensitivity, and the time of sustained-release was significantly prolonged in vitro. Hemolysis and cytotoxicity experiments showed that the SA-silica hydrogel beads were biocompatible when the TEOS molar concentration was lower than 0.375 M. The SA–silica-2 hydrogel beads had good biocompatibility, swelling properties, and slow-release properties at the same time.

Adsorptive features of cyclohexane carboxylic naphthenic acid on a novel cross-linked polymer developed from spent coffee grounds.

Naphthenic acids (NA) are organic compounds commonly found in crude oil and produced water, known for their recalcitrance and toxicity. This study introduces a new adsorbent, a polymer derived from spent coffee grounds (SCGs), through a straightforward cross-linking method for removing cyclohexane carboxylic acid as representative NA. The adsorption kinetics followed a pseudo-second-order model for the data (0.007gmin-1mg-1), while the equilibrium data fitted the Sips model ( = 140.55mgg-1). The process's thermodynamics indicated that the target NA's adsorption was spontaneous and exothermic. The localized sterical and energetic aspects were investigated through statistical physical modeling, which corroborated that the adsorption occurred indeed in monolayer, as suggested by the Sips model, but revealed the contribution of two energies per site ( ). The number of molecules adsorbed per site ) was highly influenced by the temperature as decreased with increasing temperature and increased. These results were experimentally demonstrated within the pH range between 4 and 6, where both C6H11COO-(aq.) and C6H11COOH(aq.) species coexisted and were adsorbed by different energy sites. The polymer produced was naturally porous and amorphous, with a low surface area of 20 to 30 m2g-1 that presented more energetically accessible sites than other adsorbents with much higher surface areas. Thus, this study shows that the relation between surface area and high adsorption efficiency depends on the compatibility between the energetic states of the receptor sites, the speciation of the adsorbate molecules, and the temperature range studied.

Adhesive Antibacterial Moisturizing Nanostructured Skin Patch for Sustainable Development of Atopic Dermatitis Treatment in Humans.

Atopic dermatitis (AD) is a chronic inflammatory skin disease with a complex etiology that lacks effective treatment. The therapeutic goals include alleviating symptoms, such as moisturizing and applying antibacterial and anti-inflammatory medications. Hence, there is an urgent need to develop a patch that effectively alleviates most of the AD symptoms. In this study, we employed a "green" cross-linking approach of poly(vinyl alcohol) (PVA) using glycerol, and we combined it with polyacrylonitrile (PAN) to fabricate core-shell (CS) nanofibers through electrospinning. Our designed structure offers multiple benefits as the core ensures controlled drug release and increases the strength of the patch, while the shell provides skin moisturization and exudate absorption. The efficient PVA cross-linking method facilitates the inclusion of sensitive molecules such as fermented oils. In vitro studies demonstrate the patches' exceptional biocompatibility and efficacy in minimizing cell ingrowth into the CS structure containing argan oil, a property highly desirable for easy removal of the patch. Histological examinations conducted on an ex vivo model showed the nonirritant properties of developed patches. Furthermore, the eradication of Staphylococcus aureus bacteria confirms the potential use of CS nanofibers loaded with argan oil or norfloxacin, separately, as an antibacterial patch for infected AD wounds. In vivo patch application studies on patients, including one with AD, demonstrated ideal patches' moisturizing effect. This innovative approach shows significant promise in enhancing life quality for AD sufferers by improving skin hydration and avoiding infections.

Diffusion‐induced phase separation 3D printed scaffolds for dynamic tissue repair

AbstractMany hydrogen‐bonded cross‐linked hydrogels possess unique properties, but their limited processability hinders their potential applications. By incorporating a hydrogen bond dissociator (HBD) into these hydrogels, we developed injectable 3D printing inks termed diffusion‐induced phase separation (DIPS) 3D printing inks. Upon extrusion into water and subsequent diffusion of HBD, these ink cure rapidly. The DIPS‐printed scaffold retained most of the original hydrogel properties due to the regeneration of hydrogen bonds. Additionally, the reversible nature of hydrogen bonds provides DIPS 3D‐printed scaffolds with exceptional recycling and reprinting capabilities, resulting in a reduction in the waste of valuable raw ink materials or additives. Postprocessing introduces new crosslinking methods that modulate the mechanical properties and degradation characteristics of DIPS scaffolds over a broad range. Based on its suitable mechanical properties and bioactivity, we successfully repaired and functionally reconstructed a complex defect in penile erectile tissue using the DIPS scaffold in a rabbit model. In summary, this approach is relevant for various hydrogen‐bonded cross‐linked hydrogels that offer mild printing conditions and enable the incorporation of bioactive agents. They can be used as scaffolds for dynamic tissue reconstruction, wearable devices, or soft robots.