Gel Synthesis Research Articles

Recycling leachate nanofiltration concentrate and preparing a novel and low-cost absorbent dried gel by graft polymerization

Leachate nanofiltration concentrate (LNC), characterized by its complex composition and recalcitrant contaminants, poses a significant environmental challenge. This study explores the synthesis of absorbent gels via free radical polymerization, utilizing LNC as the solvent. Employing urea as the modified material, acrylic acid (AA) as the monomer, N, N′-Methylenebisacrylamide (MBA) as the cross-linking agent, and potassium persulfate (KPS) as the initiator, the resulting gel is stable below 180 °C. It demonstrates an impressive absorbency (Q) exceeding 14.50 g/g with key gel synthesis conditions optimized via response surface methodology (RSM). Subsequent application of the prepared LNC gel in LNC treatment via low-temperature evaporation achieves remarkable pollutant removal, meeting relevant water quality standards. This gel-based LNC treatment method achieves notable reductions in carbon emission and cost to 39.2 kgCO2/kgCOD and 3.4 $/kgCOD, respectively. This study provides a cost-effective and environment-friendly approach for LNC reutilization, and exemplifies the concept of utilizing waste to treat waste, thereby mitigating environmental impact of LNC and advancing gel technology in environmental remediation.

Sol–gel synthesis and characterization of Ni-doping enhanced NixCd0.8−XZn0.2Al0.3Fe1.7O4 nanoparticles with exceptional photocatalytic activity for ciprofloxacin degradation

Sol–gel synthesis and characterization of Ni-doping enhanced NixCd0.8−XZn0.2Al0.3Fe1.7O4 nanoparticles with exceptional photocatalytic activity for ciprofloxacin degradation

Facile sol–gel synthesis process and electrochemical performance of MgNiO2 act as an electrode for supercapacitor

Abstract In this work, MgNiO2 material is prepared by a facile sol–gel method as an electrode material for supercapacitor application. The prepared MgNiO2 material is characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and elemental analysis (EDS). The electronics conductivity is 1.9 × 10−4 S cm−1. The electrochemical performance of the prepared MgNiO2 material was examined in an aqueous electrolyte of 1 M KOH. The electrochemical reaction of the prepared MgNiO2 material shows the EDLC behaviour from the shapes of the CV curves. The prepared MgNiO2 nanomaterial revealed good electrochemical performance with a maximum specific capacitance of 78 F/g at a rate of current density of 0.1 A/g. The above result delivered a simple, low cost and high-performance approach for a supercapacitor application.

Ion‐Mediated Gelation of Thermo‐Responsive Cellulose Nanofibril/Poly(N‐isopropylacrylamide) Hybrid Hydrogels with Tunable De‐Swelling Kinetics

AbstractThe tunability of the lower critical solution temperature (LCST) of poly(N‐isopropylacrylamide) (PNIPAM) to lower or higher temperatures, as well as the ease of modulation of the LCST phase transition kinetics broadens the scope of application of PNIPAM‐based materials in biomedical fields. This work reports a facile approach to formulate a smart, injectable cellulose nanofibril (CNF)/PNIPAM hybrid gel. Hofmeister salts are used to induce ion‐mediated gelation of the nanofibrils and PNIPAM chains, resulting in an interpenetrating network (IPN) structure. From rheological measurements, the hybrid material displays excellent structural integrity at room temperature and tunable thermo‐stiffening around body temperature. De‐swelling kinetics can be modulated by varying the nature and concentration of the Hofmeister ion used. The successful realization of the IPN hybrid gel structure is dependent on the molecular weight of PNIPAM used. Moreover, the hybrid gels show good thermo‐reversibility during thermal cycling, as well as excellent injectability and remarkable self‐healing post‐injection, owing to shear‐thinning and thixotropic characters. Since rheology is a crucial technique in the analysis of soft matter and flow behavior is fundamental for the design and synthesis of application‐specific viscoelastic materials, the work reported herein provides a rheological basis for careful design and synthesis of smart gels.

Fabrication of highly flexible, wearable, free-standing symmetric supercapacitors with high voltage operation enabled by hierarchical graphene/cerium oxide/polypyrrole hybrid films

Flexible, free-standing supercapacitors play a significant role in the development of future wearable energy storage devices. Herein, we successfully fabricated the highly flexible and free-standing graphene/cerium oxide/polypyrrole hybrid films by thermal reduction of graphene oxide (GO) followed by the sol–gel synthesis of CeO2 and then the addition of PPy. By regulating oxygen functional groups in GO, the electronic conductivity and electroactive sites of the hybrid films are significantly controlled, leading to enhanced energy storage capability. Finally, a symmetric flexible supercapacitor (FSC) device was developed using the prepared films as electrodes. Resulting, the integrated symmetric GO-400/CeO2/PPy FSC manifests excellent areal capacitance of 49.0 mF cm−2 at 1 mA cm−2, with a durability of 83.1 % over 10,000 cycles. Specifically, the FSC exhibited capacitance retention of 77.2 % after 10,000 cycles under bending state with exceptional rate ability. Meanwhile, an impressive energy density of 19.69 µW h cm−2 was attained at a power density of 0.85 mW cm−2. Evidently, the synergistic interactions between GO and PPy nanosheets, along with CeO2 favour the rapid electron movement of electrode material for next-generation wearable, portable electronics.

Design and Synthesis of P(AAm-co-NaAMPS)-Alginate-Xanthan Hydrogels and the Study of Their Mechanical and Rheological Properties in Artificial Vascular Graft Applications.

Cardiovascular diseases (CVDs) are the number one cause of mortality among non-communicable diseases worldwide. Expanded polytetrafluoroethylene (ePTFE) is a widely used material for making artificial vascular grafts to treat CVDs; however, its application in small-diameter vascular grafts is limited by the issues of thrombosis formation and intimal hyperplasia. This paper presents a novel approach that integrates a hydrogel layer on the lumen of ePTFE vascular grafts through mechanical interlocking to efficiently facilitate endothelialization and alleviate thrombosis and restenosis problems. This study investigated how various gel synthesis variables, including N,N'-Methylenebisacrylamide (MBAA), sodium alginate, and calcium sulfate (CaSO4), influence the mechanical and rheological properties of P(AAm-co-NaAMPS)-alginate-xanthan hydrogels intended for vascular graft applications. The findings obtained can provide valuable guidance for crafting hydrogels suitable for artificial vascular graft fabrication. The increased sodium alginate content leads to increased equilibrium swelling ratios, greater viscosity in hydrogel precursor solutions, and reduced transparency. Adding more CaSO4 decreases the swelling ratio of a hydrogel system, which offsets the increased swelling ratio caused by alginate. Increased MBAA in the hydrogel system enhances both the shear modulus and Young's modulus while reducing the transparency of the hydrogel system and the pore size of freeze-dried samples. Overall, Hydrogel (6A12M) with 2.58 mg/mL CaSO4 was the optimal candidate for ePTFE-hydrogel vascular graft applications due to its smallest pore size, highest shear storage modulus and Young's modulus, smallest swelling ratio, and a desirable precursor solution viscosity that facilitates fabrication.

Phase transition influenced photocatalytic dye degradation capability of pure and Eu-doped CoMoO4 polymorphic nanostructures

ABSTRACT The efficient degradation of organic dyes via photocatalysis presents a critical environmental challenge, necessitating advancements in catalyst design and performance. This study investigates the potential of pure and Eu doped CoMoO4 polymorphic nanostructures in addressing this challenge. Our primary focus is on enhancing the efficiency and stability of photocatalysts under diverse condition by performing sol–gel synthesis. Characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet–visible (UV-visible) analysis and Raman analysis was employed to elucidate structural and morphological changes. Our results highlight the significant enhancement in photocatalytic activity achieved through phase transitions induced by Eu doping. This enhancement is attributed to the creation defect sites and the establishment of improved charge transfer pathways within the CoMoO4 nanostructures. By shedding light on the role of phase transition in photocatalysis, this study contributes valuable insights for the design of efficient and durable photocatalysts for environmental remediation application.

Synthesis and clinical efficacy of novel jasmine titania tooth whitening gel on color, surface roughness and morphology

ObjectiveTo analyze the beneficial role of novel jasmine titania tooth whitening gel on the color, surface roughness and morphology of human tooth enamel, concerning age. MethodsGreen dentistry incorporating Jasmine flower extract was used to fabricate titania (titanium oxide) nanoparticles whose physicochemical characteristics were evaluated through X-ray diffraction spectroscopy, scanning electron microscopy, dynamic light scattering spectroscopy, atomic force microscopy and energy dispersive X-ray spectroscopy in order to produce a novel jasmine tooth whitening gel. This whitening gel was applied on maxillary central incisors ranging between 20 and 50 years, which were investigated for color change, surface roughness and morphology. ResultsThe titania nanoparticles depicted 100 % pure anatase phase, 30.3 nm size and a spherical shape with no impurities. The color change (whitening) was found to be maximum in tooth enamel from the youngest age group (20 years), but minimum for the oldest age group (50 years) (p = 0.001). No significant change in surface roughness or morphology of tooth enamel belonging to the youngest age group (20 years) (p = 0.111) and middle age group (p > 0.05) was observed, but it was statistically significant in the teeth belonging to the ultra-middle age group (40 years) and the oldest age group (50 years) (p = 0.001). ConclusionNovel jasmine titania tooth whitening gel containing titania (titanium oxide) nanoparticles prepared by jasmine flower extract revealed potent whitening effects in all the age groups without affecting their surface roughness or morphology. Clinical significanceThe latest trends emerging in aesthetic dentistry show the demand for cosmetic procedures, especially tooth whitening, is enhanced. This novel jasmine titania tooth whitening gel was potent enough to whiten the enamel belonging to different age groups without enhancing the surface roughness or adversely affecting the surface morphology.

Thermoresponsive gel containing bilirubin nanoparticles exerts anti-inflammatory effects by inhibiting neutrophil infiltration and augmenting interleukin-10 levels in carrageenan-induced rat paw edema.

Topical corticosteroids treat cutaneous inflammation but have side effects. In earlier studies, bilirubin exhibited anti-inflammatory effect, but its hydrophobicity and poor absorption limit its potential. Synthesis of bilirubin nanoparticles (BNP) and bilirubin nanoparticles gels (BNP gel) to study the anti-inflammatory effect of topical BNP gel against carrageenan-induced rat paw edema in Wistar rats. BNP were synthesized, and BNP gels were prepared by mixing BNP of different concentrations with pluronic F-127 (PF-127). A different group for each formulation was assigned with five rats in each group. After 1 h of carrageenan (1% [w/v]) injection in each group, different gels were applied topically to their respective groups. Paw edema size, percent inflammation, percent edema inhibition, and inhibition time50 were evaluated. Interleukin-10 (IL-10) levels and neutrophil infiltration in rat paw tissue were evaluated by enzyme-linked immunosorbent assay and hematoxylin and eosin, respectively. Synthesized spherical-shaped BNP had negative zeta potential. BNP gels markedly reduced paw edema size and % inflammation as compared to carrageenan and bulk bilirubin gel (Bulk B gel) treated group and significantly increased IL-10 levels and inhibited neutrophil infiltration. BNP gels exhibited a better anti-inflammatory effect than bulk B gel and comparable anti-inflammatory potential with clobetasol.

Sol–gel synthesis and characterization of silica intertwined bismuth-based bioactive glass coalescence possibility towards biological applications

Sol–gel synthesis and characterization of silica intertwined bismuth-based bioactive glass coalescence possibility towards biological applications

Exploring BiFeO3/Fe3O4 nanocomposite for possible application in magnetic hyperthermia

The development of perovskite/spinel nanocomposite BiFeO3/Fe3O4 (BFO/FO) holds particular interest for applications in magnetic hyperthermia therapy (MHT). This work offers a significant avenue for advancing material properties and evaluating the heating efficiency, considering the impact of structure, and magnetic characteristics within the perovskite/spinel system. A sol–gel synthesis process for phase-pure BiFeO3 production was successful, which is subsequently utilized with Fe3O4 to form a nanocomposite (BiFeO3)1−x/(Fe3O4)x. Our findings indicate that increasing the concentration of Fe3O4 in the nanocomposite enhances the saturation magnetization and the specific absorption rate (SAR). Importantly, the addition of BiFeO3 to Fe3O4 further enhances the nanocomposite's heating efficiency. This study underscores the potential of perovskite/spinel nanocomposites in realizing advanced materials with tailored properties and multifaceted functionalities.

A composite gel formed by konjac glucomannan together with Nano-CF obtained by FeCl3-citric acid hydrolysis as a potential fat substitute

This study aims to fabricate composite gels using nano citrus fiber (Nano-CF) derived from the hydrolysis process of citric acid (CA) with FeCl3, with a simultaneous exploration of its potential as an substitute to fats. Investigation of varying FeCl3 concentrations (0.01 to 0.03 mmol/g of CA) revealed a significant enhancement in the water-holding and oil-retention capacity of the Nano-CF. The meticulous synthesis of the composite gels involved integrating nano citrus fibers with konjac glucomannan (KGM) through high-speed shearing, followed by a comprehensive evaluation of its microstructure and physicochemical attributes. Increasing the Nano-CF concentration within the gels led to a synergistic interaction with KGM, resulting in enhanced viscosity, improved thermal stability, and restricted water molecule mobility within the system. The gels initially displayed reduced firmness, resilience, and adhesive characteristics, followed by subsequent improvement. When the ratio of Nano-CF to KGM was 0.5:1, the composite gels exhibited texture parameters, viscosity, and viscoelastic stability comparable to whipped animal cream formulations. These findings provide a new idea for the application of Nano-CF/KGM composite gels in whipped cream.

Comparison of sol–gel and hydrothermal synthesis methods on the physical, and photocatalytic properties of Bi1−xCexFe1−xAlxO3 ferrites

Comparison of sol–gel and hydrothermal synthesis methods on the physical, and photocatalytic properties of Bi1−xCexFe1−xAlxO3 ferrites

Eco-friendly high entropy oxide rock-salt type structure for oxygen evolution reaction obtained by green synthesis

Global energy consumption increases year after year, causing the depletion of non-renewable sources. According to the International Energy Agency (IEA), global demand for electrical energy is expected to increase by 3.3 % in 2024. Therefore, developing new renewable sources is urgent, including new devices for energy storage and conversion, particularly those based on electrochemical reactions. Water splitting is a clean and sustainable technology capable of facing this issue by producing oxygen and hydrogen from water and electricity. However, an issue related to this technology is the slow kinetics of oxygen evolution reaction, making it necessary to develop new electrocatalysts with high electrochemical performance. To meet this requirement, this work deals, for the first time, with a high entropy oxide with a rock-salt structure synthesized by a green sol–gel synthesis using red seaweed (Rhodophyta) as a polymerizing agent. Sol-gel synthesis allows the large-scale production of nanomaterials with high uniformity and dispersion of the involved chemical elements. The literature, which discussed the synthesis of these oxides, reveals that agents harmful to the environment are employed, including sodium hydroxide, acetic acid, hexadecyltrimethylammonium bromide, urea, and ammonium hydroxide. The composition of the high entropy oxide is (Mg0.2Ni0.2Co0.2Cu0.2Zn0.2)O. As electrocatalyst for oxygen evolution reaction, it exhibits a low overpotential (336 mV vs. RHE at 10 mA cm−2), a Tafel slope of 68 mV dec-1, and excellent durability. The electrochemical performance of the high entropy oxide prepared in this work is superior to other electrocatalysts of the same class that were produced using transition metal-based precursors.

Affinity gel synthesis from the p-aminobenzoic acid derivative 4-amino-2-methylbenzoic acid and purification of polyphenol oxidase from various plant sources

The polyphenol oxidase (PPO) enzyme, which causes enzymatic browning, has been repeatedly purified from fruit and vegetables by affinity chromatography. In the present research, Sepharose 4B-l-tyrosine-4-amino-2-methylbenzoic acid, a novel affinity gel for the purification of the PPO enzyme with high efficiency, was synthesized. Additionally, Sepharose 4B-l-tyrosine-p-aminobenzoic acid affinity gel, known in the literature, was also synthesized, and 9.02, 16.57, and 28.13 purification folds were obtained for the PPO enzymes of potato, mushroom, and eggplant by the reference gel. The PPO enzymes of potato, mushroom, and eggplant were purified 41.17, 64.47, and 56.78-fold from the new 4-amino-2-methylbenzoic acid gel. Following their isolation from the new affinity column, the assessment of PPO enzyme purity involved the utilization of SDS-PAGE. According to the results from SDS-PAGE and native PAGE, the molecular weight of each enzyme was 50 kDa. Then, the inhibition effects of naringin, morin hydrate, esculin hydrate, homovanillic acid, vanillic acid, phloridzin dihydrate, and p-coumaric acid phenolic compounds on purified potato, mushroom, and eggplant PPO enzyme were investigated. Among the tested phenolic compounds, morin hydrate was determined to be the most potent inhibitor on the potato (Ki: 0.07 ± 0.03 μM), mushroom (Ki: 0.7 ± 0.3 μM), and eggplant (Ki: 4.8 ± 1.2 μM) PPO enzymes. The studies found that the weakest inhibitor was homovanillic acid for the potato (Ki: 1112 ± 324 μM), mushroom (Ki: 567 ± 81 μM), and eggplant (Ki: 2016.7 ± 805.6 μM) PPO enzymes. Kinetic assays indicated that morin hydrate was a remarkable inhibitor on PPO.

Enhancing dielectric properties of ZnO nanopowders with 2D hBN doping: production, structural, morphological and dielectric characterization

In this study, it was aimed to improve the dielectric properties of ZnO nanoparticles with the addition of hBN, which was not previously available in the literature, and thus to expand their usage areas. Sol–gel synthesis method was used in this study to create pure and hexagonal boron nitride (hBN) doped zinc oxide (ZnO) nanoparticles. Zinc acetate dihydrate Zn(CH3COO)22H2O), sodium hydroxide NaOH, and hexagonal boron nitride (hBN), all from Sigma Aldrich, were used as starting reagents. The reagents were dissolved during the sol–gel synthesis by being heated to 90 °C for 4 h in a magnetic stirrer. FT-IR, XRD, FE-SEM, EDX characterization techniques, and impedance analyzer were used to find functional groups, structural, morphological, and chemical composition, and dielectric properties of the nanoparticles, respectively. The produced un-doped and hBN-doped ZnO particles consist of nano-sized structures. Changes occurred in the intensities and locations of the XRD diffraction peaks and FT-IR peaks with the addition of hBN. Characteristic peaks of both ZnO and hBN were observed in the diffraction peaks of the doped nanoparticles. All nanoparticles were of high purity and were successfully produced by the sol–gel method. It was shown that as the hBN doping level increased, there were more hBN nanoplates in the ZnO matrix, and the EDX results also showed an increase in hBN addition. The frequency stability of the dielectric properties improved after hBN doping. While the dielectric constant at 1 kHz frequency at room temperature is 12.07 in pure ZnO nanoparticles, the increase up to 55.21 is observed in 10% hBN doped nanocomposites. This situation is considered as a great potential for technological applications of this novel nanocomposite material.

Postharvest Chemical Treatment of Physiologically Induced Stem End Blockage Improves Vase Life and Water Relation of Cut Flowers

Wound-induced xylem occlusion significantly affects the vase life of cut flowers, as oxidative stress and the polymerization of phenolic compounds lead to the deposition of phenolic compounds/secondary metabolites in the stem ends of cut flowers to heal open tissues of freshly cut stems and prevent microbial invasion. However, this deposition causes blockage of vessels, reduced water uptake, and shortened vase life. The physiological plugging of vessels is linked with various oxidative enzymes’ (PAL, PPOs, LACs, and COs) actions taken to increase the synthesis of different compounds, e.g., lignin, suberin, tyloses, gel, and latex, in wounded areas. The use of chemical preservatives/enzyme inhibitors is one of the safest and most efficient techniques employed to minimize vascular blockage and inhibit phenolic compounds deposition and exudation. This review mainly discusses the types of oxidative enzymes, their pathways and biochemistry along with production of secondary metabolites, their biosynthesis, and their modes of action involved in vascular blockage. It also summarizes the different types of preservatives used in postharvest treatments to improve relative water uptake, flower fresh weight, petal protein content, and hydraulic conductance and prolong the vase life of cut flowers during storage. It is hoped that this elaborate study will help researchers in designing new studies concerning occlusion caused by the accumulation of phenolic compounds in vessels.

Influence of Yb3+ percentage on emission of Er3+ doped into GdVO4 matrix

In this study, we used the non-hydrolytic sol–gel methodology to synthesize gadolinium vanadate particles doped with different Er3+ and Yb3+ molar ratios. Er3+ and Yb3+ chlorides and vanadium alkoxide were used as precursors during the sol–gel synthesis. The resulting powders were treated at 800 °C and characterized by x-ray diffraction and photoluminescence. The x-ray diffractogram displayed peaks attributed to the gadolinium vanadate matrix. Photoluminescence helped to evaluate the Fluorescence Intensity Ratio (FIR), which is important for understanding the nanothermometer property. The FIR of the GdVO4:Er3+/Yb3+ samples containing different Er3+ and Yb3+ molar ratios increased as a function of the laser power, which indicated that the local temperature increased. The excitation spectra obtained at fixed wavelengths of 525 and 555 nm displayed bands at 322, 379, and 489 nm, ascribed to the charge transfer band and Er3+ levels. Upon excitation at 321 nm, the emission spectra in the visible region presented intense bands at 525 and 555 nm, due to Er3+ emission, and excitation at 321 nm led to emission in the infrared region, 980 and 1550 nm. In conclusion, the synthesized system can be employed as a temperature sensor.

Visible‐Light Tempted Photocatalytic Activity of Newly Synthesized Co3O4NiOPdOPd Nanomaterial for Removal of Azo Dyes

AbstractTo contribute to the development of sustainable and effective nano‐catalyst for dye degradation is greatly enviable to solve the global environmental remediation problems. In this regard, here facile Co3O4NiOPdOPd nanomaterial was synthesized via phyto‐organic fuel and scrutinized as nanocatalyst to degrade methyl orange (MO). The Co3O4NiOPdOPd nanomaterial was synthesized following the sol gel synthesis methodology using foliar phyto extract of Abies pindrow Royle leaves. The synthesized nanomaterial of Co3O4NiOPdOPd was studied by X‐rays diffraction, Raman spectroscopy, Energy‐dispersive spectroscopy, as well as Field‐emission scanning electron microscopy. Fourier transform infrared spectroscopy, Gas chromatography and Mass spectrometry. The facile bio nanomaterial was studied for removal of MO both under sunlight and under dark. Fabricated nanocatalyst of mixed metal oxides (MMO) exhibited the degradation efficiency of 95 % in the presence of sunlight and 85 % without sunlight (in dark condition) in 15 minutes.The comparison of catalytic potential of MOD‐L and MOD‐D for Co3O4−NiO−PdO−Pd for 2 minutes exhibited maximum degradation percent MOD‐L (72.2.4 %) followed by MOD‐D (51.5 %). However, after 20 minutes MOD‐L exhibited higher percentage of 95.4 % while MOD‐D revealed 84.8 percent degraded MO. Consequently, the nano‐scale features have enhanced the catalytic performance of Co3O4NiOPdOPd photocatalyst towards water purification from organic pollutants.

A new visible light-sensitive, oxygen-tolerant photoinitiator system for the synthesis of polyacrylamide gels by maskless photopolymerization

A new bis(2,2’-bypiridine)(1,10-phenanthroline)ruthenium(II) chloride–sodium bromate–malonic acid system has been developed for visible light-initiated polymerization of acrylamide. Its application allows the use of digital maskless photolithography to create 2D figures from polyacrylamide gel and their ansamblies. The system was used to create a chemical logic element ‘AND’.