Gel Microspheres Research Articles

Mesoporous Silica Supported Hydrophilic Ionic Liquid Gel Microspheres for Solvent-Free Deep Oxidative Desulfurization.

Solvent-free oxidative desulfurization can avoid environmental pollution caused by organic solvents as well as prevent loss of fuel during the oil-water separation process. In this work, first, hydrophilic ionic liquid gel microspheres with [BMIM]BF4 and PHEMA as the dispersion medium and gel network, respectively, were successfully prepared by using mesoporous silica microspheres as a supporting skeleton capable of stabilizing the gel through an anchoring effect, and then the catalyst [BMIM]PW and oxidant H2O2 were incorporated into the gel microspheres to construct a liquid compartment microreactor for deep desulfurization. The prepared microreactor (SiO2@[BMIM]PW/ILG-microspheres) has excellent extraction-catalytic capacity and exhibited ∼100% desulfurization ratio for a model oil of n-heptane with 500 ppm of DBT at 60 °C for 3 h without solvents. Additionally, the prepared microreactor can absorb hydrophilic desulfurization products after the reaction and has advantages of reusability and simple recovery without polluting the fuel oil, which is beneficial for potential petroleum industrial application.

Effective elimination of internal phosphorus pollution with MgFe-LDHs hybrid material in eutrophic water: The chemical forms, transformation mechanism, and dynamic relationships

The internal phosphorus (P) pollution is a major cause of water eutrophication. Although the traditional powders materials, with good performance, were difficult to recycle due to its shape, and the reaction mechanism between materials and internal P was rarely elucidated. In this work, a hydrotalcite composite material (MgFe-LDHs hybrid gel microspheres) was prepared via chemical crosslinking to eliminate internal P pollution both in overlying water and sediments effectively. Benefiting from the strong coordination between iron hydroxide on the MgFe-LDHs surface and internal P, the P adsorption capacity was up to 1256.38 mg/kg under natural conditions, the IP (NaOH-P and HCl-P) and OP were 78 % and 22 %, respectively. During 40-days remediation experiment, with the addition of MgFe-LDHs hybrid gel microspheres, whatever in the mixed or the capped, promoted a conversion from stable P to soluble active P of NaOH-P in sediments, and thus contributing to an easy adsorption of NaOH-P by MgFe-LDHs hybrid gel microspheres (The NaOH-P in sediments decreased by 16 % and 22 %, respectively). Meanwhile, the excessive stable HCl-P (only a minor portion) that could not be adsorbed by MgFe-LDHs remained in the form of Ca-P in sediments. Additionally, the MgFe-LDHs hybrid gel microspheres improved the microbial community structure, and the microorganism was involved in the elimination of internal P simultaneously. In summary, this study proposed a promising remediation approach to resolve the problem of internal P pollution in eutrophic water with high efficiency, cost-effective, and environmentally friendly.

Efficient Nitrogen Removal from Low-C/N Ratio Wastewater by a New Gel Microsphere with Nitrate-Reducing Fe(II)-Oxidizing Bacteria

Efficient Nitrogen Removal from Low-C/N Ratio Wastewater by a New Gel Microsphere with Nitrate-Reducing Fe(II)-Oxidizing Bacteria

Mechanism of remediation of U(VI) contaminated simulated soil by AC‐nHAP gel microsphere as PRB combined electrokinetic technology

Mechanism of remediation of U(VI) contaminated simulated soil by AC‐nHAP gel microsphere as PRB combined electrokinetic technology

Design, synthesis, and characterization of novel copolymer gel particles for water-plugging applications

Abstract Multi-stage plugging represents a promising strategy for enhancing production and injection rates in medium-and low-permeability oilfields. Despite its potential, the efficacy of current plugging agents, particularly hydrophobically bonded water-soluble polyacrylamide-based gel microspheres, is hindered by notable drawbacks such as low stability and inadequate compressive strength. Therefore, a comprehensive understanding of water plugging mechanisms coupled with the optimization of gel microsphere properties is essential for advancing the development of gel-based plugging agents with superior characteristics or intelligent regulatory capabilities. The P(AA-AM-[PrSO3]Vim) ionic liquid copolymerized gel particles were designed and synthesized by using microfluidic technique and titration gel method with AM, acrylic acid (AA), 1-vinylimidazole (Vim) and 1,3-propylsulfonyl lactone (PrSO3) as the raw materials. The morphology and structure of the copolymer gel particles were characterized, and the effects of [PrSO3]Vim and cross-linker content on the water-absorbing properties and strength of the gel particles were investigated. When the amount of [PrSO3]Vim was 12%, the concentration of crosslinker was 1.5%, and the temperature was 40°C, the water absorption capacity reached the maximum value of 163 g·g−1. The strength of the P(AA–AM–[PrSO3]Vim) spherical gel particles was maximized at a [PrSO3]Vim content of 4%. Furthermore, the chemical and physical roles of the P(AA–AM–[PrSO3]Vim) spherical gel particles were studied in a typical water-plugging environment. This study provides experimental data and a theoretical basis for the application of functional spherical gel-plugging particles in current oilfield environments.

Formulation and evaluation of herbal microsphere gel

Formulation and evaluation of herbal microsphere gel involves designing a gel-based delivery system for herbal active ingredients encapsulated within microspheres. The process typically includes selecting suitable herbal extracts, encapsulating them into microspheres using techniques like solvent evaporation or emulsion-solvent evaporation, and then incorporating these microspheres into a gel base. Evaluation criteria may include physical characteristics (particle size, morphology), drug release kinetics, rheological properties, stability, and efficacy of the herbal ingredients. This approach aims to enhance the stability, controlled release, and therapeutic efficacy of herbal compounds, offering potential applications in various fields including pharmaceuticals, cosmetics, and personal care products. This present study demonstrated the effectiveness of carbopol based herbal gel containing extracts of tamarind possessing antibacterial activity. Thus, the formulated herbal gel incorporated with tamarind extracts show great promises in the management of antibacterial activity. Gel loaded with microspheres of tamarind was prepared with aim to deliver the drug which passes through transdermal route as it provides quick onset of action when compared to oral route. This gel loaded with microspheres of tamarind was successfully prepared using solvent evaporation method.

TiO2/Ti3C2Tx gel microsphere for efficient photocatalytic degradation of organic pollutant with excellent recycling stability

Enhancing the recycling stability of photocatalysts is crucial for practical applications. The significant loss of powder catalyst materials during the recycling process hampers its degradation rate and results in a low reuse rate. Herein, the in-situ prepared TiO2/Ti3C2Tx (TOTC) heterojunction is embedded in gel microsphere (GMS) as a recyclable photocatalyst TOTC@GMS for efficient photocatalytic degradation of Congo red (CR). The experimental results show that the removal rate can reach 99 % in 120 min without any co-catalysts or sacrificial reagents. The GMS can be recycled after rinsing in deionized water for only 2 min, and the removal rate still maintains over 90 % after 25 cycles. Additionally, under natural sunlight exposure, TOTC@GMS achieves a removal rate of 90 % for CR in real water samples. The degradation mechanism is elucidated through hydroxyl radicals (OH) and superoxide radicals (O2−) as the main reactive species, as confirmed by free radical scavenging and electron paramagnetic resonance (EPR) experiments. The degradation products are further analyzed using high-performance liquid chromatography-mass spectrometry (LC-MS), allowing for the deduction of degradation pathways of CR. Furthermore, a phytotoxicity test confirms the non-toxicity of the organic micromolecules generated after degradation. This study presents a practical strategy to improve the recycling stability of photocatalysts, thereby effectively reducing the cost of wastewater treatment.

Coupling atomization, emulsification, and polymerization steps for creating gel microspheres

Coupling atomization, emulsification, and polymerization steps for creating gel microspheres

Preparation and Characterization of Responsive Cellulose-Based Gel Microspheres for Enhanced Oil Recovery.

As an important means to enhance oil recovery, ternary composite flooding (ASP flooding for short) technology has achieved remarkable results in Daqing Oilfield. Alkalis, surfactants and polymers are mixed in specific proportions and injected into the reservoir to give full play to the synergistic effect of each component, which can effectively enhance the fluidity of crude oil and greatly improve the oil recovery. At present, the technology for further improving oil recovery after ternary composite flooding is not mature and belongs to the stage of technical exploration. The presence of alkaline substances significantly alters the reservoir's physical properties and causes considerable corrosion to the equipment used in its development. This is detrimental to both the environment and production. Therefore, it is necessary to develop green displacement control agents. In the reservoir environment post-ASP flooding, 2-(methylamino)ethyl methacrylate and glycidyl methacrylate were chosen as monomers to synthesize a polymer responsive to alkali, and then grafted with cellulose nanocrystals to form microspheres of alkali-resistant swelling hydrogel. Cellulose nanocrystals (CNCs) modified with functional groups and other materials were utilized to fabricate hydrogel microspheres. The product's structure was characterized and validated using Fourier transform infrared spectroscopy and X-ray diffraction. The infrared spectrum revealed characteristic absorption peaks of CNCs at 1165 cm-1, 1577 cm-1, 1746 cm-1, and 3342 cm-1. The diffraction spectrum corroborated the findings of the infrared analysis, indicating that the functional modification occurred on the CNC surface. After evaluating the swelling and erosion resistance of the hydrogel microspheres under various alkaline conditions, the optimal particle size for compatibility with the target reservoir was determined to be 6 μm. The potential of cellulose-based gel microspheres to enhance oil recovery was assessed through the evaluation of Zeta potential and laboratory physical simulations of oil displacement. The study revealed that the absolute value of the Zeta potential for gel microspheres exceeds 30 in an alkaline environment with pH values ranging from 7 to 14, exhibiting a phenomenon where stronger alkalinity correlates with a greater absolute value of Zeta potential. The dispersion stability spans from good to excellent. The laboratory oil displacement simulation experiment was conducted using a cellulose-based gel microsphere system following weak alkali ASP flooding within the pH value range from 7 to 10. The experimental interventions yielded recovery rates of 2.98%, 3.20%, 3.31%, and 3.38%, respectively. The study indicates that cellulose-based gel microspheres exhibit good adaptability in alkaline reservoirs. This research offers a theoretical foundation and experimental approaches to enhance oil recovery techniques post-ASP flooding.

Mechanical Properties, Drug Release, Biocompatibility, and Antibacterial Activities of Modified Emulsified Gelatin Microsphere Loaded with Gentamicin Composite Calcium Phosphate Bone Cement In Vitro.

Bone defects are commonly addressed with bone graft substitutes; however, surgical procedures, particularly for open and complex fractures, may pose a risk of infection. As such, a course of antibiotics combined with a drug carrier is often administered to mitigate potential exacerbations. This study involved the preparation and modification of emulsified (Em) crosslinking-gelatin (gel) microspheres (m-Em) to reduce their toxicity. The antibiotic gentamicin was impregnated into gel microspheres (m-EmG), which were incorporated into calcium phosphate bone cement (CPC). The study investigated the effects of m-EmG@CPC on antibacterial activity, mechanical properties, biocompatibility, and proliferation and mineralization of mouse progenitor osteoblasts (D1 cells). The average size of the gel microspheres ranged from 22.5 to 16.1 μm, with no significant difference between the groups (p > 0.05). Most of the oil content within the microspheres was transferred through modification, resulting in reduced cytotoxicity. Furthermore, antibiotic-impregnated m-EmG did not compromise the intrinsic properties of the microspheres and exhibited remarkably antibacterial effects. After combining with CPC (m-EmG@CPC), the microspheres did not significantly hinder the CPC reaction and produced the main product, hydroxyapatite (HA). However, the compressive strength of the largest microsphere content of 0.5 wt.% m-EmG in CPC decreased significantly from 59.8 MPa of CPC alone to 38.7 MPa of 0.5m-EmG@CPC (p < 0.05). The 0.5m-EmG@CPC composite was effective against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) in drug release and antibacterial tests. Compared with m-EmG alone, the 0.5m-EmG@CPC composite showed no toxicity to mouse fibroblast cells (L929). Additionally, the proliferation and mineralization of mouse osteoblastic osteoprogenitor cells (D1 cells) did not have a negative impact on the 0.5m-EmG@CPC composite over time in culture compared with CPC alone. Results suggest that the newly developed antibacterial 0.5m-EmG@CPC composite bone cement did not negatively affect the performance of osteoprogenitor cells and could be a new option for bone graft replacement in surgeries.

Real-Time pH Sensor in Bacterial Microenvironments Using Liquid Crystal Core-Shell Microspheres.

It is well-known that the bacterial microenvironment imposes restrictions on the growth and behavior of bacteria. The localized monitoring of microenvironmental factors is appreciated when consulting bacterial adaptation and behavior in the presence of chemical or mechanical stimuli. Herein, we developed a novel liquid crystal (LC) biosensor in a microsphere configuration for real-time 3D monitoring of the bacteria microenvironment, which was implemented by a microfluidic chip. As a proof of concept, a LC gel (LC-Gel) microsphere biosensor was prepared and employed in the localized pH changes of bacteria by observing the configuration change of LC under polarized optical microscopy. Briefly, the microsphere biosensor was constructed in core-shell configuration, wherein the core contained LCE7 (a nematic LC) doped with 4-pentylbiphenyl-4'-carboxylic acid (PBA), and the shell encapsulated the bacteria. The protonation of carboxyl functional groups of the PBA induced a change in charge density on the surface of LCE7 and the orientation of E7 molecules, resulting in the transitions of the LC nucleus from axial to bipolar. The developed LC-Gel microspheres pH sensor exhibited its dominant performance on localized pH real-time sensing with a resolution of 0.1. An intriguing observation from the prepared pH biosensor was that the diverse bacteria impelled distinct acidifying or alkalizing effects. Overall, the facile LC-Gel microsphere biosensor not only provides a versatile tool for label-free, localized pH monitoring but also opens avenues for investigating the effects of chemical and mechanical stimuli on cellular metabolism within bacterial microenvironments.

Ionic liquid gel microspheres as multifunctional bi-component additives for the crystallinity manipulation and defect passivation in all-air-processed perovskite solar cells

Additives have played a critical role in enhancing the efficiency and stability of perovskite solar cells (PSCs). At present, most of the effective additives are composed of one component, with little attention being given to the potential of bi-component. Herein, we report a novel synergistic strategy to construct ionic liquid gel microspheres (ILG-microspheres) as multifunctional bi-component additives by emulsion polymerization. The synergistic effect of polymeric methyl methacrylate and 1-butyl-3-methylimidazole hexafluorophosphate (BMIMPF6) can effectively improve perovskite crystallization quality and passivated GBs. As a result, an all-air-processed champion device with ILG-microsphere exhibits a power conversion efficiency of 22.31 % with a Voc of 1.206 V. Moreover, the long-term stability of optimized PSC remains 86.5 % of initial efficiency after being stored in the air atmosphere for 1500 h, and its thermal stability is also enhanced. This exploitation of ILG-microsphere as multifunctional bi-component additives provides a promising strategy for the development of all-air-processed high-performance PSCs.

Construction of Dome-Shaped 3D Corneal Epithelial Tissue Models Based on Eyeball-Shaped Gel Microspheres.

By overcoming interspecies differences and mimicking the in vivo microenvironment, three-dimensional (3D) in vitro corneal models have become a significant novel tool in contemporary ophthalmic disease research. However, existing 3D corneal models struggle to replicate the actual human corneal environment, especially the dome-shaped physiological structure with adjustable curvature. Addressing these challenges, this study introduces a straightforward method for fabricating collagen/chitosan-alginate eyeball-shaped gel microspheres with a Janus structure via a two-phase aqueous system, used subsequently to construct in vitro 3D corneal epithelial tissue models. By adjusting the diameter ratio of collagen/chitosan to alginate droplets, we can create eyeball-shaped gel microspheres with varying curvatures. Human corneal epithelial cells were seeded on the surfaces of these microspheres, leading to the formation of in vitro 3D corneal epithelial tissues characterized by dome-like multilayers and tight junctions. Additionally, the model demonstrated responsiveness to UVB exposure through the secretion of reactive oxygen species (ROS) and proinflammatory factors. Therefore, we believe that in vitro 3D corneal epithelial tissue models with dome-shaped structures hold significant potential for advancing ophthalmic research.

Gel microspheres enhance the stemness of ADSCs by regulating cell-ECM interaction

The gel microsphere culture system (GMCS) showed various advantages for mesenchymal stem cell (MSC) expansion and delivery, such as high specific surface area, small and regular shape, extensive adjustability, and biomimetic properties. Although various technologies and materials have been developed to promote the development of gel microspheres, the differences in the biological status of MSCs between the GMCS and the traditional Petri dish culture system (PDCS) are still unknown, hindering gel microspheres from becoming a culture system as widely used as petri dishes. In the previous study, an excellent “all-in-one” GMCS has been established for the expansion of human adipose-derived MSCs (hADSCs), which showed convenient cell culture operation. Here, we performed transcriptome and proteome sequencing on hADSCs cultured on the “all-in-one” GMCS and the PDCS. We found that hADSCs cultured in the GMCS kept in an undifferentiation status with a high stemness index, whose transcriptome profile is closer to the adipose progenitor cells (APCs) in vivo than those cultured in the PDCS. Further, the high stemness status of hADSCs in the GMCS was maintained through regulating cell-ECM interaction. For application, bilayer scaffolds were constructed by osteo- and chondro-differentiation of hADSCs cultured in the GMCS and the PDCS. The effect of osteochondral regeneration of the bilayer scaffolds in the GMCS group was better than that in the PDCS group. This study revealed the high stemness and excellent functionality of MSCs cultured in the GMCS, which promoted the application of gel microspheres in cell culture and tissue regeneration.

Glycosylated stimuli responsive polyacrylamide microspheres with in-situ formed AgNPs for bacterial capture, detection and killing

Infections due to multidrug resistant bacteria are a major concern and cause for human mortality worldwide. Materials that can selectively capture, and eliminate these pathogens have turned into a priority. Development of excellent point-of-care material/system that can help in the visual detection of the captured bacterial cells in addition to their killing capability can be advantageous. In this study, we demonstrate the synthesis of a hitherto unknown glycosylated gel microspheres that can capture, kill and detect pathogenic bacteria. Silver nanoparticles (AgNPs) loaded glucose/mannose/galactose functionalized microspheres namely; PAM-Glc, PAM-Man and PAM-Gal, were synthesized by inverse emulsion polymerization. The sugar functionalities present on the microspheres interacts with the bacterial cell wall leading to capture of the cells while the antibacterial action was brought about by the AgNPs synthesized in-situ within the microspheres. The highlight of the designed system is visual indication of bacterial capture due to aggregation of gel microspheres and an indicative colour change of AgNPs. The capture kinetics of bacterial cells using PAM-Man was faster compared to PAM-Glc and PAM-Gal. Among the AgNPs loaded glyco microspheres, silver loaded mannose microspheres (Ag@PAM-Man) exhibited greater inhibition against E. coli and antibiotic resistant S. aureus cells. Bacterial cells captured by PAM-Man, exhibited pink coloration upon interaction with Resorufin β-glucuronide; suggesting the destruction of bacteria upon adhesion to microspheres. The plausible mechanistic aspects involved in the capture, detection and killing process is also discussed.

Innovative Acrylic Resin-Hydrogel Double-Layer Coating: Achieving Dual-Anchoring, Enhanced Adhesion, and Superior Anti-Biofouling Properties for Marine Applications.

Traditional anti-corrosion and anti-fouling coatings struggle against the harsh marine environment. Our study tackled this by introducing a novel dual-layer hydrogel (A-H DL) coating system. This system combined a Cu2O-SiO2-acrylic resin primer for anchoring and controlled copper ion release with a dissipative double-network double-anchored hydrogel (DNDAH) boasting superior mechanical strength and anti-biofouling performance. An acrylamide monomer was copolymerized and cross-linked with a coupling agent to form the first irreversible network and first anchoring, providing the DNDAH coating with mechanical strength and structural stability. Alginate gel microspheres (AGMs) grafted with the same coupling agent formed the second reversible network and second anchoring, while coordinating with Cu2+ released from the primer to form a system buffering Cu2+ release, enabling long-term antibacterial protection and self-healing capabilities. FTIR, SEM, TEM, and elemental analyses confirmed the composition, morphology, and copper distribution within the A-H DL coating. A marine simulation experiment demonstrated exceptional stability and anti-fouling efficacy. This unique combination of features makes A-H DL a promising solution for diverse marine applications, from ship hulls to aquaculture equipment.

Eco-Friendly Spiking Approach Based on Microfluidics for Preparation of Matrix Reference Materials.

Medicated bath is the most common spiking method used in the development of matrix reference materials for aquatic products; however, the environmental issues caused by the treatment of waste liquid after medicated bath cannot be ignored. We proposed an environmentally friendly spiking method based on microfluidics, which significantly improved the drug utilization rate without the need for subsequent drug residue treatment. Finely processed minced fish samples were fully mixed with quinolone drugs, and minced fish gel microspheres were prepared by microfluidic technology, utilizing the gel's water-locking function to enhance the drug-loading capacity. The results showed that this method can significantly increase the drug-loading capacity of the matrix (2.33-4.03 times) compared with the traditional spiking methods. In addition, the matrix reference material prepared by this method has good stability, and the drug concentration was adjustable and controllable.

Preparation of UN microspheres by external gelation

Uranium mono-nitride (UN) microspheres are expected to play an important role in various miniaturization module reactors. The combination of UN core and tri-structural-isotropic (TRISO) coatings will bring improved efficiency and safety. Carbon-containing gel microspheres were prepared by external gelation, followed by carbothermal reduction and nitridation to synthesize UN. The effects of C/U molar ratios and heat-treatment schemes on the composition and microstructures of UN microspheres were studied. The results indicated that the external gelation could be used to prepare UN microspheres, with the highest UN content of 93 wt%.

Graphene quantum dot-based hydrogel microspheres for sensitive detection of caffeic acid

In this investigation, blue-emitting graphene quantum dots (B,N-GQDs) were synthesized via a single-step hydrothermal method in an ethanol/water mixture utilizing 3-APBA as the nitrogen and boron sources. These B,N-GQDs showcased a highly graphitized structure, complemented by surface-functionalized boronic acid and amino groups that bestowed upon them remarkable optical attributes and water solubility. Leveraging the interplay of internal filtering and dynamic quenching effects, the sensor demonstrated remarkable selectivity and sensitivity in detecting caffeic acid (CA) within the range of 0–840 μM, achieving a limit of detection (LOD) of 0.63 μM. Moreover, the fluorescent gel microspheres engineered with B,N-GQDs exhibited robust CA sensing capabilities and portability. As such, the application potential of B,N-GQDs expands to encompass drug metabolism monitoring, alongside the assessment of food and environmental safety.

Improving and controlling the drug loading capacity of seven quinolones in minced fish matrix based on microfluidics

Traditional spiking methods for preparing matrix reference material of aquatic products is difficult to control the drug content in the matrix, especially one matrix containing multiple drugs. Minced fish is commonly used for the preparation of matrix reference materials in aquatic products, which is a relatively complex matrix with stickiness and difficult handling. Drug loading capacity is a key factor affecting the effectiveness of matrix reference materials. Here, we proposed a new spiking approach to improve the drug loading capacity of seven quinolones based on microfluidics, simultaneously. Fresh grass carp tissue underwent grinding, fine filtration, centrifugation and reconstituted in distilled water to form a liquid sample, which was subsequently mixed with a sodium alginate solution (1 %) at a ratio of 1:1.2. The mixed solution was supplemented with seven quinolones of equal concentration, followed by the preparation of uniform fish gel microspheres using microfluidic technology. The results indicated that the recoveries of seven quinolones ranged from 82.54 % to 114.17 %, demonstrating a significant improvement in the drug loading capacity of these quinolones compared to traditional methods. Moreover, the drug concentration in the matrix can be precisely controlled. A strong linear relationship was observed between the concentration of seven quinolones in the matrix and its initial concentration, which could serve as a reference for the development of other matrix reference materials.