Cross-linked Polymer Research Articles

Immobilization of carbonic anhydrase on modified PES membranes for artificial lungs.

The introduction of carbonic anhydrase (CA) onto an extracorporeal membrane oxygenation (ECMO) membrane can improve the permeability of carbon dioxide (CO2). However, existing CA-grafting methods have limitations, and the hemocompatibility of current substrate membranes of commercial ECMO is not satisfactory. In this study, a 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC)/N-hydroxy succinimide (NHS) activation method is adopted to graft CA with CO2-catalyzed conversion activity onto a polyethersulfone (PES) membrane, which is prepared by a phase inversion technique after in situ crosslinking polymerization of 1-vinyl-2-pyrrolidone (VP) and acrylic acid (AA) in PES solution. The characterization results reveal that CA has been grafted onto the modified PES membrane successfully and exhibits catalytic activity. The kinetic parameters of esterase activity verify that the grafted amount of active CA increases with an increase in the concentration of the CA incubation solution. The CA-grafted membrane (CA-M) can accelerate the conversion of bicarbonate to CO2 in water and blood, which demonstrates the special catalytic activity towards bicarbonate of CA. Finally, blood compatibility tests prove that the CA-M does not lead to hemolysis, shows suppressed protein adsorption and increased coagulation time, and is suitable for application in ECMO. This work demonstrates a green and efficient method for preparing bioactive materials and has practical guiding significance for subsequent pulmonary membrane research and ECMO applications.

Covalent Organic Framework Impregnated with Silver and Copper Nanoparticles: An Advanced Approach for Catalytic Degradation of Organic Pollutants in Wastewater.

In this study, we introduce an economically viable and scalable process for developing a novel covalent organic framework (COF), which is a cross-linked polymer. The resulting material, TzTFB-COF, is successfully functionalized with silver and copper nanoparticles, which show high adequacy in the degradation of nitroaromatic compounds (NACs). For the synthesis of TzTFB-COF, s-tetrazine diamine (Tz) and 1,3,5-triformylbenzene (TFB) are chosen as building blocks, which exhibit a high density of nitrogen-containing sites. TzTFB-COF shows good chemical and thermal stability (>300 °C). For functionalization of TzTFB-COF with silver and copper nanoparticles, a solution infiltration technique is used. The composite materials, i.e., Ag@TzTFB-COF and Cu@TzTFB-COF, have been characterized using various spectroscopic and analytical techniques, which show high activity, high selectivity, and excellent chemical and thermal stability up to 350 °C. The silver and copper contents of Ag@TzTFB-COF and Cu@TzTFB-COF are determined to be 9.6 and 12.4 wt % by inductively coupled plasma optical emission spectrometer (ICP-OES). The catalytic efficiency of the synthesized Ag@TzTFB-COF and Cu@TzTFB-COF materials is assessed in the context of catalyzing the hydrogenation of NACs. Experimental results reveal a remarkable catalytic performance when conducted in an aqueous medium, and notably, the materials demonstrate substantial potential for reusability across multiple catalytic cycles. The determined parameters for the catalytic hydrogenation reaction, i.e., the rate constants and Gibbs free energies, are found to be 0.0185 s-1 and 9.878 kJ/mol for Ag@TzTFB-COF and 0.0219 s-1 and 9.615 kJ/mol for Cu@TzTFB-COF. Thus, the catalytic reaction exhibits characteristics of endothermic, endergonic, and nonspontaneous nature.

A Fully Amorphous, Dynamic Cross-Linked Polymer Electrolyte for Lithium-Sulfur Batteries Operating at Subzero-Temperatures.

Solid-state lithium-sulfur batteries have shown prospects as safe, high-energy electrochemical storage technology for powering regional electrified transportation. Owing to limited ion mobility in crystalline polymer electrolytes, the battery is incapable of operating at subzero temperature. Addition of liquid plasticizer into the polymer electrolyte improves the Li-ion conductivity yet sacrifices the mechanical strength and interfacial stability with both electrodes. In this work, we showed that by introducing a spherical hyperbranched solid polymer plasticizer into a Li+ -conductive linear polymer matrix, an integrated dynamic cross-linked polymer network was built to maintain fully amorphous in a wide temperature range down to subzero. A quasi-solid polymer electrolyte with a solid mass content >90 % was prepared from the cross-linked polymer network, and demonstrated fast Li+ conduction at a low temperature, high mechanical strength, and stable interfacial chemistry. As a result, solid-state lithium-sulfur batteries employing the new electrolyte delivered high reversible capacity and long cycle life at 25 °C, 0 °C and -10 °C to serve energy storage at complex environmental conditions.

Studying the Interaction of Viteral Substitutes with the Surface of Acrylic Intraocular Lenses

Purpose of the study: In vitro to study the degree of adhesion of vitreous substitutes, such as silicone oil of various viscosities and perfluorodecalin (PFOS), to hydrophobic acrylic polymer IOLs and evaluate the interaction of vitreous substitutes with the model MIOL-Soft-23 in the clinic. Material and methods. IOLs of the model MIOL-Soft-23 were taken for the experiment. MIOL-Soft-23 are included in the RPR-20 set. IOL of the model MIOL-Soft-23 is made by photopolymerization from a biocompatible spatially cross-linked hydrophobic acrylic polymer based on oligomers and monomers of the methacrylic series with filters in the ultraviolet region of the spectrum from 19 to 23 D. For the experiment, silicone oils of different viscosities were taken: RS-OIL 2000 (Alchimia), SIL-5000-S (DORC), Oxane 5700 (Bausch & Lomb), PFOS (perfluorodecalin) Dk-line (Bausch & Lomb). Also, saline sodium chloride 0.9 % (Solofarm) was used. Results. Revealed a decrease in the degree of silicone adhesion to the surface of acrylic hydrophobic IOLs as the temperature rises, not less than 1.5 %. The absence of dependence of the degree of adhesion on the degree of viscosity of silicone oil was confirmed, which corresponds to the literature data. For the first time, the average percentage of adhesion of perfluorodecalin to the IOL surface data were obtained, in particular, the MIOL-Soft-23 model. The range of values ranged from 0.7 to 7.2 %. The average coverage percentage is 1.9 ± 1.3 % (exposure at 37 ± 1 °C for up to 14 days) and 3.4 ± 1.5 % (exposure at room temperature for up to 14 days). This confirms the need for careful intraoperative monitoring of the completeness of removal of PFOS droplets from the IOL surface. Conclusion. The presence of the risk of adhesion of residual drops of silicone oil and PFOS to the surface of the IOL necessitates careful intraoperative control of the completeness of the removal of vitreous body substitutes, as well as further search for the best ways to eliminate this complication. The conducted complex of studies makes it possible to recommend the use of IOL model MIOL-Soft-23 in complicated cases of vitreal surgery.

Redundant microtubule crosslinkers prevent meiotic spindle bending to ensure diploid offspring in C. elegans.

Oocyte meiotic spindles mediate the expulsion of ¾ of the genome into polar bodies to generate diploid zygotes in nearly all animal species. Failures in this process result in aneuploid or polyploid offspring that are typically inviable. Accurate meiotic chromosome segregation and polar body extrusion require the spindle to elongate while maintaining its structural integrity. Previous studies have implicated three hypothetical activities during this process, including microtubule crosslinking, microtubule sliding and microtubule polymerization. However, how these activities regulate spindle rigidity and elongation as well as the exact proteins involved in the activities remain unclear. We discovered that C. elegans meiotic anaphase spindle integrity is maintained through redundant microtubule crosslinking activities of the Kinesin-5 family motor BMK-1, the microtubule bundling protein SPD-1/PRC1, and the Kinesin-4 family motor, KLP-19. Using time-lapse imaging, we found that single depletion of KLP-19KIF4A, SPD-1PRC1 or BMK-1Eg5 had minimal effects on anaphase B spindle elongation velocity. In contrast, double depletion of SPD-1PRC1 and BMK-1Eg5 or double depletion of KLP-19KIF4A and BMK-1Eg5 resulted in spindles that elongated faster, bent in a myosin-dependent manner, and had a high rate of polar body extrusion errors. Bending spindles frequently extruded both sets of segregating chromosomes into two separate polar bodies. Normal anaphase B velocity was observed after double depletion of KLP-19KIF4A and SPD-1PRC1. These results suggest that KLP-19KIF4A and SPD-1PRC1 act in different pathways, each redundant with a separate BMK-1Eg5 pathway in regulating meiotic spindle elongation. Depletion of ZYG-8, a doublecortin-related microtubule binding protein, led to slower anaphase B spindle elongation. We found that ZYG-8DCLK1 acts by excluding SPD-1PRC1 from the spindle. Thus, three mechanistically distinct microtubule regulation modules, two based on crosslinking, and one based on exclusion of crosslinkers, power the mechanism that drives spindle elongation and structural integrity during anaphase B of C.elegans female meiosis.

High-k dual crosslinkable polymer nanocomposite dielectrics based on P(MMA-co-HEMA)/BaTiO3 for film capacitors

High-k dual crosslinkable polymer nanocomposite dielectrics based on P(MMA-co-HEMA)/BaTiO3 for film capacitors

Nanogel: Types, Methods of Preparation, Limitation, Evaluation and Application – A Systematic Review

Nanogels combine the characteristics of nanomaterials with hydrogels. To meet the expanding demands from various areas, a sizable number of nanogels have been designed and manufactured using the emulsion solvent diffusion nano precipitated method, emulsion evaporation of the solvent method, reverse micellar method and modified diffusion emulsification method. Thermosensitive nanogel, pH-sensitive nanogel, ultrasound-sensitive magnetic response, response to multiple stimuli, chain transfer polymerization, photo-induced crosslinking polymerization and modifications for active targeting are the types of nanogels based on response towards stimuli and polysaccharide, chitosan, pullulan, hyaluronic acid, alginate, cyclodextrin, gum acacia, protein are used to prepare nanogel. Nanogels have considerable potential and novelty within the biomedical sector due to their uniformity, adjustable dimensions, little toxicity, resilience in the presence of serum, and capacity for responsive behavior with a comparatively high drug encapsulation capacity. Nanogels have considerable potential in bioactive substance delivery, organ targeting, and chemotherapy. The article highlighted the preparation, types, evaluation and applicability of nanogel as a targeted delivery system.

Firefighting Gel Polymer Electrolyte for Non-Flammable Li-Ion Batteries Based on Extremely Low Amount of a Cross-Linkable Polymer

Safety issues of lithium-ion batteries(LIBs) have caught a priority of concerns as the electric vehicle(EV) market expands dramatically and requires higher energy densities. To be free from a variety of unpredictable situations and environments triggering such a safety issue, materials that provide a mechanism to control the factors causing fire and explosion are required to be involved in LIB cells.In this work, we present a gel polymer electrolyte(GPE) characterized by nonflammability and fire-extinguishing capability by radical scavenging(Rs). This GPE was realized within battery cells by in situ crosslinking a small amount of a cross-linkable fluoro-functionalized cyanoethyl polyvinyl alcohol(F7) in conventional carbonate electrolytes having LiPF6. The cyanoethyl functional groups(-CN) is responsible for gelation by cross-linking while the fluorine-containing moiety terminated radical chain reactions triggering thermal runaway by Rs. The strong interaction between the polymer and solvent molecules restricted solvent volatility. The tiny solid content at 2 wt. % in GPE guaranteed a liquid-level ionic conductivity at 9 mS/cm, disallowing battery performances to be sacrificed. Formation of the LiF-dominant solid-electrolyte-interphase(SEI) layer on anodes was encouraged by the fluoro-moiety of F7.In previous research of our group, PVA-CN was used as cross-linkable polymer for enhancement of mechanical property with additional metal-chelating functional group. Hydroxy group of PVA-CN is useful to modify the functional group by DCC coupling mechanism. Herein, as same as previous modification, the Heptafluorobutyric acid(HFB) was used for non-flammability and battery performance. F7 was expected to not only increase thermal stability but also scavenge the radicals. In addition, LiF-rich SEI layers would be made by fluorine groups.First, GPE increase its thermal stability by strong interaction between cross-linked polymer matrix and organic solvents. The binding energy of ethylene carbonate (EC) and hydrogen of cyanoethyl side chain was 0.4 eV which is stronger compared with general hydrogen bond(0.2 eV). Therefore, the flammable gas generation was suppressed by strong interaction between solvents and polymer matrix.In addition, the flash point demonstrated the strong interaction in GPE. The flash point of GPE which contained different polymer contents was decreased as the ratio of polymer content was increased. The composition of the atmosphere in the devices changed into more flammable because of the higher ratio of EMC gas in the atmosphere within enough time to equilibrate. In other words, EC forms a greater number of strong interactions with the polymer matrix while the polymer contents increased. The SET test of 2 wt.% PVA-CN-based GPE(G2)(3.36 s/g) and 5 wt.% PVA-CN-based GPE(G5)(0 s/g) proved that higher contents of PVA-CN in GPE ensure the non-flammability.Second, to overcome the poor electrochemical ability of G5, Rs functionalized F7 was used instead of PVA-CN. Unlike G2, only with 2 wt. % of F7 guaranteed the 0 s/g of SET. Non-flammability of 2 wt.% F7-based GPE(FG2) is due to the fluorine moiety scavenge the O• or H•. In the nail penetration test, only the FG2 was not exploded and maintained charged voltage while the nail penetrates the whole pouch cell vertically because of its elasticity.The Rs capability was demonstrated by cyclic voltammetry(CV) with 2,2’-azobisisobutyronitrile(AIBN) and alpha-tocopherol(α-TOH). After α-TOH react with AIBN radicals at the 70 ℃, the oxidation current decreased because of consumption of α-TOH. The Rs capability was calculated by ratio of current retention of α-TOH oxidation current with a same amount of among scavenger additives. The Rs capability of F7 was 214%.Lastly, our findings suggest sufficient non-flammability without battery performances degradation. The capacity retention of FG2 was higher than LE at the 300th Cycles. This is because the fluorine moiety contributed to make LiF-rich SEI layers. The rigid SEI layers and GPE suppressed volume expansion of graphite. Also, the capacity fade was not observed in FG2 with higher current density. The reason for great rate capability is higher lithium-ion conductivity which is a multiplication of ionic conductivity and lithium-ion transference number(tLi+). FG2has 4.82 of lithium-ion conductivity, while 3.63 in LE. Therefore, the mass transfer resistance was not large on the electrode surface due to the higher lithium-ion mobility in FG2.In this work, the non-flammability and battery performance were successfully demonstrated by thermal stability and Rs capability without any battery performances degradation. The thermal stability was enhanced by strong intermolecular forces between polymer chain and polar organic solvents. The radical chain reaction was terminated by fluorine moiety of GPEs matrix. The capacity retention of FG2 was outstanding compared with LE. Therefore, due to the FG2, the battery will be able to ensure non-flammability without degradation of performance. Figure 1

Constructing Stable Solid Electrolyte Interphase Using Gel Polymer Electrolytes for Anode-Free Lithium Metal Batteries with Enhanced Cycle Life

Anode-free lithium metal batteries (AFLMBs) have recently emerged as next-generation batteries due to high energy density, reduced cost, and simplified manufacturing process due to the absence of reactive metallic lithium. However, developing high-performance AFLMBs faces several challenges for practical applications, such as low coulombic efficiency and poor cyclability, due to the dendrite growth of lithium and side reactions of lithium with liquid electrolytes. To develop the AFLMBs with long cycle life, it is necessary to attain high coulombic efficiency since there is no excessive lithium to compensate for irreversible Li inventory losses in the AFLMB. Three-dimensional cross-linked gel polymer electrolyte (GPE) can be a good candidate for stabilizing the lithium metal by encapsulating organic solvents in the polymer matrix, leading to reduction of the parasitic reactions between lithium metal and liquid electrolyte, which results in high coulombic efficiency of AFLMBs. In this work, we prepared a cross-linked GPE using a multi-functional cross-linking agent to realize high coulombic efficiency and long cycle life of AFLMBs with LiNixCoyAl1-x-yO2(NCA) cathode (areal capacity of 4.76 mAh cm-2). Moreover, the GPE capable of coordinating with lithium ions could construct stable solid electrolyte interphase by regulating lithium ion solvation structures. Cycling performance was investigated in the voltage range of 3.6 – 4.3 V at 0.5 C rate. The Cu/GPE/NCA cell exhibited a capacity retention of 80% after 150 cycles, which was higher than that of AFLMB with liquid electrolyte. Electrochemical characterization and spectrometry were performed to investigate how the GPE could improve the cycling performance of AFLMBs.

Nonflammable Gel Polymer Electrolyte for Lithium-Ion Batteries with Enhanced Safety and High-Temperature Performance

Lithium-ion batteries (LIBs) have become dominant power sources for various applications such as mobile electronics, electric vehicles and energy storage systems. However, liquid electrolytes currently used in LIBs have critical drawbacks such as flammability and leakage problem. In this regard, various electrolyte systems have been developed to enhance the battery safety while maintaining cycling performance. Among them, the chemically cross-linked gel polymer electrolytes (GPEs) can enhance the thermal safety of LIBs by effectively encapsulating organic solvents in the polymer matrix. However, they usually contain large amounts of organic solvents to achieve high ionic conductivity, making GPE be still flammable. To solve these problems, we designed and synthesized a novel phosphorus-based cross-linking agent with excellent flame retardancy. GPE was prepared by in-situ thermal curing of gel precursor containing liquid electrolyte and phosphorus-based cross-linking agent. The obtained GPE exhibited high ionic conductivity and nonflammability. The GPE was applied to lithium-ion cells composed of graphite anode and LiNi0.6Co0.2Mn0.2O2 cathode. Our results revealed that the lithium-ion cell employing GPE exhibited enhanced safety and improved high-temperature cycling performance compared to the cell with the liquid electrolyte.

Quasi-Solid-State All-V2O5 Battery.

Solid-state symmetrical battery represents a promising paradigm for future battery technology. However, its development is hindered by the deficiency of high-performance bipolar electrodes and compatible solid electrolytes. Herein, a quasi-solid-state all-V2O5 battery constructed by a binder-free carbon fabric-V2O5 nanowires@graphene (CVOG) bipolar electrode and a softly cross-linked polyethylene oxide-based solid polymer electrolyte (SPE) is reported. The synergetic effect of nano-structuring of V2O5, hierarchical conductive network, and graphene wrapping endows the CVOG electrode with boosted reaction kinetics and suppressed vanadium dissolution. The cathodic and anodic reactions of CVOG are decoupled by electrochemical analysis, conceiving the feasibility of constructing all-V2O5 full battery. In manifesting the solid-state all-V2O5 battery, the robust and elastic SPE exhibits high ionic conductivity, tight/self-adaptable electrolyte-electrode contact, and a low charge-transfer barrier. The resultant solid-state full battery exhibits a high reversible capacity of 158mAhg-1 at 0.1C, good capacity retention of over 61% from 0.1C to 2C, and remarkable cycling stability of 77% capacity retention after 1000 cycles at 1C, which surpass other solid-state symmetrical batteries. Hence, this work provides a practice of high-performance solid-state batteries with symmetrical configuration and is constructive for next-generation battery technology.

(Invited) All-Solid-State Na- and K-Ion Batteries with Dry Polymer Electrolytes

The development of sodium-ion and potassium-ion batteries has gained increasing attention as a sustainable and cost-effective alternative to lithium-ion batteries, due to the abundance of their constituent elements.[1]-[3] All-solid-state batteries offer high safety advantages in high-temperature conditions, as their solid composition reduces the risk of leakage or ignition of the organic electrolyte. As large-scale and stationary batteries for energy storage applications require safety and durability in wide-temperature operations, all-solid-state sodium-ion and potassium-ion batteries can provide a potential solution.This study presents the fabrication of all-solid-state sodium batteries, using dry polymer electrolytes, optimized for stable operation at 60 °C.[4] A composite electrode with uniformly dispersed conductive carbon and binder polymer is essential to achieve a stable charge-discharge reaction in all-solid-state cell, due to the absence of the liquid electrolyte penetrated in the electrode pores. The use of a polymer electrolyte as a binder polymer provides an effective ionic conduction path inside the electrode, which allows stable charge-discharge reaction even at the thick composite electrodes. The fabricated all-solid-state Na // P2-Na2/3[Ni1/3Mn2/3]O2 cell exhibits superior cycle performance at 60 °C, compared to the liquid electrolyte. Furthermore, coating P2-Na2/3[Ni1/3Mn2/3]O2 with Al-oxide enhances the capacity retention of the P2-Na2/3[Ni1/3Mn2/3]O2 // hard carbon full cell, with a mean discharge voltage of 3.11 V and energy density of 148 Wh (kg of active material)−1. To the best of our knowledge, this is the highest value ever reported for full-cell operation of an all-solid-state sodium-ion battery using a dry-polymer electrolyte.The study also reports the fabrication of all-solid-state potassium batteries, where the effects of K metal pretreatment on the K metal/solid polymer electrolyte interface were investigated.[5] The use of K metal chunk, pretreated with the electrolytes containing potassium bis(fluorosulfonyl)amide (KFSA), effectively suppressed polarization and interfacial resistance during continuous K metal stripping-deposition reactions in the cross-linked polymer electrolyte, poly[ethylene oxide-co-2-(2-methoxyethoxy)ethyl glycidyl ether-co-allyl glycidyl ether] (P(EO/MEEGE/AGE)). The addition of 1,3,2-dioxathiolane 2,2-dioxide (DTD) to the pretreatment solution further decreased polarization and interfacial resistance, due to the formation of a stable passivation layer on K metal by FSA− ions and DTD. The efficient operation of the potassium iron hexacyanoferrate positive electrode and graphite negative electrode in P(EO/MEEGE/AGE), with the K metal counter electrode, was achieved by effectively suppressing interfacial resistance through pretreatment. Stable K metal counter electrode for all-solid-state potassium cell was also beneficial to design full cell of all-solid-state potassium-ion cell, enabling us to fabricate the first 3 V-class all-solid-state K-ion battery operated at room temperature.

Peptide Gel Electrolytes for Stabilized Zn Metal Anodes.

The rechargeable aqueous Zn ion battery (AZIB) is considered a promising candidate for future energy storage applications due to its intrinsic safety features and low cost. However, Zn dendrites and side reactions (e.g., corrosion, hydrogen evolution reaction, and inactive side product (Zn hydroxide sulfate) formation) at the Zn metal anode have been serious obstacles to realizing a satisfactory AZIB performance. The application of gel electrolytes is a common strategy for suppressing these problems, but the normally used highly cross-linked polymer matrix (e.g., polyacrylamide (PAM)) brings additional difficulties for battery assembly and recycling. Herein, we have developed a gel electrolyte for Zn metal anode stabilization, where a peptide matrix, a highly biocompatible material, is used for gel construction. Various experiments and simulations elucidate the sulfate anion-assisted self-assembly gel formation and its effect in stabilizing Zn metal anodes. Unlike polymer gel electrolytes, the peptide gel electrolyte can reversibly transform between gel and liquid states, thus facilitating the gel-involved battery assembly and recycling. Furthermore, the peptide gel electrolyte provides fast Zn ion diffusion (comparable to conventional liquid electrolyte) while suppressing side reactions and dendrite growth, thus achieving highly stable Zn metal anodes as validated in various cell configurations. We believe that our concept of gel electrolyte design will inspire more future directions for Zn metal anode protection based on gel electrolyte design.

Preparation of Preformed Submicron Crosslinked Polymer Coils for Conformance Control in Low-Permeability Reservoirs.

With the increasing development of low-permeability reservoirs, the significance of conformance control treatment has risen considerably. To address the conflict between injectability and plugging performance, as well as to enhance the deep migration capacity of conformance control agents, preformed submicron crosslinked polymer coils (SCPCs) have been manufactured using aqueous solution dispersion polymerization. Fourier transform infrared and scanning electron microscopy were employed to examine the chemical structure and micromorphology, while particle size distribution, zeta potential, rheological, and filtration properties were analyzed. The effectiveness of conformance control was confirmed through the parallel core displacement. The effective particle size of SCPCs was at a submicron level (500~800 nm). SCPCs exhibit a transitional threshold concentration between gel and sol states (0.25 wt%~0.5 wt%). SCPCs can efficiently block the 1.2 μm microporous filter membrane. The filtration time is up to 67.8 min. SCPCs can improve the water absorption rate of lower permeability cores from 21.21% to 57.89% with a permeability difference of 5. Therefore, SCPCs have good injectability, plugging performance, and deep migration capacity and can be used for conformance control in low-permeability reservoirs.

Herbal nanogels: Revolutionizing skin cancer therapy through nanotechnology and natural remedies

The escalating global incidence of skin cancer demands innovative therapeutic approaches that balance efficacy and reduced side effects. The convergence of nanotechnology and medicinal research has unveiled herbal nanogels as promising candidates for advancing skin cancer therapy. Skin cancer, comprising diverse malignancies, necessitates novel strategies to enhance treatment outcomes. Nanogels, intricate networks of cross-linked polymers at the nanoscale, have emerged as versatile vehicles for targeted drug delivery. Their ability to encapsulate a range of therapeutic agents and respond to stimuli offers a platform to revolutionize treatment paradigms. The taxonomy of nanogels encompasses physical cross-linked gels, liposome-modified nanogels, micellar nanogels, hybrid nanogels, and chemically cross-linked nanogels, each holding distinctive characteristics suitable for specific applications. The synthesis of nanogels is a precise craft involving techniques like photolithography, micro-moulding, and emulsion methods, enabling control over particle size, morphology, and drug-loading capacity. Stimuli-responsive nanogels present a dynamic facet of this field, exhibiting potential for targeted drug delivery. Noteworthy examples include LHRH-targeted nanogels and nanogels responsive to the intricate microenvironment of bacterial-accumulated tumors. One of the most intriguing developments lies in the fusion of herbal medicine and nanotechnology, paving the way for herbal nanogels. By incorporating bioactive plant-derived compounds into nanogel matrices, these constructs offer a holistic therapeutic approach. The convergence of nanotechnology and herbal medicine in the form of herbal nanogels presents a promising avenue for elevating skin cancer therapy. Through precise drug delivery mechanisms and responsiveness to complex microenvironments, nanogels exhibit a potential to reshape treatment norms. This comprehensive review provides an in-depth roadmap of the evolving landscape of herbal nanogels, illuminating their potential as effective, targeted, and minimally invasive tools for combating skin cancer.

Probing the Solubility of Imine-Based Covalent Adaptable Networks.

Covalent adaptable networks (CANs) are polymer materials that are covalently cross-linked via dynamic covalent bonds. The cross-linked polymer network is generally expected to be insoluble, as is seen for traditional thermosets. However, in recent years, it has become apparent that-under certain conditions-both dissociative and associative CANs can be dissolved in a good solvent. For some applications (e.g., those that require long-term (chemical) stability), the solubility of CANs can be problematic. However, many forget that (selective) solubility of CANs can also be applied advantageously, for example, in recycling or modification of the materials. In this work, we provide results and insights related to the tunable solubility of imine-based CANs. We observed that selected CANs could be fully dissolved in a good solvent without observing dissociation of imines. Only in an acidic environment (partial) dissociation of imines was observed, which could be reverted to the associated state by addition of a base. By adjusting the network composition, we were able to either facilitate or hamper solubility as well as control the size of the dissolved particles. DLS showed that the size of dissolved polymer particles decreased at lower concentrations. Similarly, decreasing cross-linking density resulted in smaller particles. Last, we showed that we could use the solubility of the CANs as a means for chemical recycling and postpolymerization modification. The combination of our studies with existing literature provides a better understanding of the solubility of CANs and their applications as recyclable thermosets.

Anion-Exchange Electrospun Mixed-Matrix Polymer Fibers of Colesevelam for Water Treatment.

Novel anion-exchange electrospun fiber membranes of polycaprolactone doped with the cationic, cross-linked colesevelam polymer are reported. The weight fraction of cross-linked cationic colesevelam polymer, as the active phase within the PCL matrix, can readily be controlled in the synthesis of the mixed-matrix fibers (Cole@PCL), enabling optimization of the ion-exchange properties of the resulted membranes. This approach enabled adaptation of anion-exchange resins to a permeable, flexible membrane form, which is a significant advancement toward futuristic water treatment applications, demonstrated herein for the removal of trace contaminants, including nitrates and phosphates, as well as anionic dyes. The Cole@PCL membranes demonstrated the dependence of contaminant uptake on the weight percentage of colesevelam in the mixed-matrix membrane. An optimal 10 wt % of colesevelam was identified, demonstrating a staggering ion removal capacity of 155.8 mg/g for nitrate, 177.6 mg/g for phosphate, and 70 mg/g for Methyl Orange.

IMPROVED SORPTION OF PRASEODYMIUM IONS FROM NITRATE SOLUTIONS BY ACTIVATED ION EXCHANGERS

In this research, we investigated the praseodymium ions sorption by the ion exchangers KU-2-8 (H+form) and AV-17-8 (OH-form) as an interpolymer system called "KU-2-8:AV-17-8" (X:Y) with the molar ratio of ionic groups X:Y (6:0, 5:1, 4:2, 3:3, 2:4, 1:5, and 0:6) in praseodymium nitrate solution. To be clear, two cross-linked polymers having active functional groups that are in the same solution but not in direct contact form an interpolymer system. The purposeof our research to demonstrate how activating ion exchangers as functional polymers by remote contact in an aqueous medium enhances the sorption of a variety of valuable metals and their compounds from industrial waste solutions, including praseodymium. Objects.Ion exchangers that are mutually activated in an aqueous medium undergo conformational and electrochemical changes that lead to a shift in their state from neutral to highly ionized and an increase in their sorption activity toward target metal ions. Results.The experimental findings showed that the sorption activity of the interpolymer system KU-2-8:AV-17-8 (5:1) increased significantly when compared to praseodymium ions (43 %), but the sorption activity of the raw KU-2-8 (6:0) and raw AV-17-8 (0:6) had the same values of 25 % and 5 %, respectively. Conclusion. This research sheds light on a novel and promising approach to improve the efficiency of ion exchangers, opening possibilities for the effective recovery and removal of valuable metals from complex solutions. Additionally, it holds practical implications for sustainable waste management and resource recycling, contributing to the advancement of environmental protection and resource conservation in various industrial sectors. Further investigations and optimization of the interpolymer system could yield substantial benefits for greener and more resource-efficient future sorption technologies.

Combined effect of acetoacetoxy - Amine interparticle crosslinking and different TG polymer phases to obtain high performance waterborne wood coatings

Two strategies to overcome the film formation dilemma of waterborne binders are combined to produce hard coatings at low temperature without the need of high amounts of coalescing agents, namely crosslinking during film formation and the mixture of soft and hard polymer phases. The crosslinking chemistry used is the one between acetoacetoxy functionalized latexes and amine functionalized ones. Crosslinked and non-crosslinked binder films are investigated by DMTA analysis to study the crosslinking degree and the degree of interdiffusion between polymeric phases in each case. TEM and AFM analysis are also used to support the results obtained by DMTA. The prepared binders are then incorporated in a pigmented coating formulation and tested for wood coating applications such as hardness development, blocking resistance, water resistance and wet adhesion. The relative effect of crosslinking and the presence of different TG phases are investigated by making a comparative study with non-crosslinked paints.

Synthesis and characterization of modified PVC waste with different diamines for Hg(II) removal

PVC waste, after removing contamination (P1), was cross-linked with 1,3-diaminopropane, hexamethylenediamine and 1,4-diaminonaphthalene (P2, P3 and P4). The cross-linked PVC was characterized by FTIR, SEM and CHN elemental analysis. The influence of the type of crosslinking agent on the thermal properties and swelling of PVC was also investigated. P3 was characterized by the highest water absorption, and P4 had the best thermal stability. All cross-linked polymers showed good effectiveness in removing Hg(II) ions, especially PVC modified with hexamethylenediamine.