Gel Particles Research Articles

Study of the Factors Influencing the Adsorption of Heavy Metal Pollutants in Water by Activated Carbon Gel Particles

Study of the Factors Influencing the Adsorption of Heavy Metal Pollutants in Water by Activated Carbon Gel Particles

Texture of emulsion-filled pea protein-potato starch gels: Effect of processing conditions and composition

From a physicochemical perspective, foods like vegan cheese and meat analogues are complex multicomponent gels. The aim of this study was to investigate the effect of processing conditions and composition on the textural properties of multicomponent gels containing starch, pea protein isolate (PPI) and emulsion droplets. Mechanical properties were measured, and structural analysis was carried with CLSM and SEM. In the case of particle gels prepared with maize starch (MS), a higher shearing speed decreased Young's modulus, fracture stress and fracture strain due to break up of the starch granules. In polymer gels prepared with potato starch (PS), structure and mechanical properties were not much affected by processing conditions. The addition of emulsion droplets increased the Young's modulus of MS gels and decreased that of PS gels. In PS gels, the fracture stress decreased further for smaller oil droplets. The addition of emulsion droplets was also found to decrease adhesiveness, cohesiveness and chewiness, regardless of the matrix structure. With protein addition into PS gels, an increase in Young's modulus and a decrease in fracture strain were observed. These results show that processing conditions and composition can be used to modulate the physical properties of complex food systems.

2024 SPE Pioneers of Improved Oil Recovery

Reservoirs present plenty of complexity and mystery. Four oil recovery experts have helped remove some of those mysteries, taming the complex to boost production. From developing preformed particle gels that improve conformance when fractures cause severe channeling to simulating enhanced oil recovery (EOR) processes in the reservoir to identifying the aqueous stability concept to demonstrating the distance polymer solutions can travel without degradation, the four 2024 recipients of the 2024 Improved Oil Recovery (IOR) Pioneer Award have made a “sustained and important contribution to increased oil recovery,” Randy Seright, New Mexico Tech, 2024 Pioneer selection committee chairman and 2008 honoree, told JPT. Seright, four other previous recipients of the recognition, and 2024 SPE IOR Conference General Chairman Tom McCoy evaluated a field of 16 nominees for the lifetime achievement honor and selected four who have throughout their careers “made the most lasting and significant contributions to IOR,” Seright said. “It’s why we are where we are today with respect to IOR.” The 2024 IOR Pioneer recipients who were honored during the biannual IOR conference in Tulsa in April are Baojun Bai, professor of petroleum engineering, who sits in the Lester Birbeck Endowed Chair at Missouri University of Science and Technology (Missouri S&T) in Rolla, Missouri; Mojdeh Delshad, research professor in the Hildebrand Department of Petroleum and Geosystems Engineering at The University of Texas at Austin (UT-Austin); Varadarajan Dwarakanath, team lead for chemical EOR at the Chevron Technology Center in Houston; and Stephane Jouenne, who previously led a TotalEnergies team dedicated to surface and subsurface research topics for polymer flooding and is currently CO2 capture project coordinator at TotalEnergies. “It’s the most prestigious award given out in IOR,” Seright said.

Effects of Eucommia ulmoides leaf powder on the gelatinization, rheology, and gel properties of sweet potato starch

This study aimed to explore the feasibility of employing Eucommia ulmoides leaf powder (ELP), which is a novel medicinal and food homologous material, to improve the physicochemical properties of sweet potato starch (SPS) gel. The effects of ELP on the gelatinization, rheology, and gel properties of SPS were investigated. The Brabander viscosity test results showed that ELP could reduce the peak viscosity, trough viscosity, final viscosity, and setback value of SPS. The rheological tests showed that the SPS-ELP gels had shear-thinning behavior, and that the ELP could decrease the apparent viscosity, shear stress, G′, G″ of SPS-ELP gels and make the gels exhibit stronger liquid-like behavior. The X-ray diffraction pattern indicated that the ELP could decrease the relative crystallinity and retard retrogradation of SPS-ELP gels, which was cofirmed by microscopic structure analysis. The ELP had a significant effect on the color difference of the gels, resulting in a yellow-green color. The addition of ELP also reduced the hardness of SPS-ELP gels, and increased the median particle size D50, volume mean diameter D [4,3], and area mean diameter D [3,2] of gel particle size distribution. These findings suggest that ELP has a good potential in improving starch gel properties.

Two Cd(II) complexes: Fluorescence performances and loaded with paclitaxel-hydrogel on oral cancer treatment

In this study, two unique three-dimensional Cd(II)-based coordination polymers, [Cd3L12(H2O)4]∙(CH3CN)∙(H2O) (1) and [Cd3L22(H2O)2] (2), were successfully synthesized under solvothermal conditions. The organic linkers selected were two tricarboxylic acid ligands, H3L1 and H3L2 (H3L1 = 4,4′,4″-((benzene-1,3,5-tricarbonyl) tris(azanediyl)) tribenzoic acid, H3L2 = 4,4′,4″-(benzene-1,3,5-triyltris(azanediyl))tribenzoic acid). Furthermore, fluorescence performance tests of the complexes indicated that through coordination with the metal center and the semi-rigid triangular ligand, as well as the formation of a highly rigid network involving the framework and free solvent molecules in a hydrogen bond network, complexes 1 and 2 exhibited excellent blue fluorescence. Building upon this, given the poor biocompatibility of metal–organic frameworks (MOFs) as carriers, we employed hyaluronic acid (HA)/carboxymethyl chitosan (CMCS) hydrogel for encapsulation and paclitaxel loading. A novel paclitaxel drug delivery system, HA/CMCS-MOFs@paclitaxel, was developed, and the effects of the two systems on the expression of the cancer proliferation marker gene Ki-67 in OSCC cells (CAL27) were evaluated. Results demonstrated that the synthesized paclitaxel-loaded metal gel particles exhibited potent inhibitory activity against Ki-67, showcasing their potential as therapeutics for oral cancer.

Experimental Study of the Swelling and Rheological Properties of a High-Strength Preformed Particle Gel Lost Circulation Material

Summary Preformed particulate gel (PPG) has emerged as a widely utilized lost circulation material in deep oil and gas drilling operations. The objective of our study was to devise a high-strength preformed particle gel (HSPPG) specifically designed to address drilling fluid loss in high-temperature fractured formations. To achieve this, a comprehensive set of laboratory experiments was conducted to assess the swelling and rheological properties of HSPPG under various conditions, and these investigations aimed to provide deeper insights into the pressure-bearing mechanism exhibited by HSPPG. The synthesis of HSPPG involved the copolymerization of acrylamide (AM) and N-hydroxymethacrylamide (NMA) molecular chains, catalyzed by organic peroxides, to form the primary network. Additionally, to enhance its temperature resistance, urea-formaldehyde (UF) resin, known for its superior thermal stability, was incorporated into the secondary network. This unique combination of primary and secondary networks imparted remarkable thermal endurance and structural stability to the resulting HSPPG. The swelling and rheological experiments revealed that HSPPG, with a particle size of 1000 µm, exhibited an equilibrium swelling rate (SR) value of 30.55 and a storage modulus (G’) of 1050 Pa at 120℃. These findings attested to its excellent temperature resistance and structural stability. Furthermore, when subjected to a sodium chloride solution at a temperature of 120℃ and a concentration of 25.0%, HSPPG achieved equilibrium swelling with an SR value of 24.93 and a G’ of approximately 7000 Pa. This significant increase in structural strength was attributed to charge shielding within the highly concentrated brine environment. In the plugging experiments, a wedge-shaped slit with an inlet of 3 mm and an outlet of 1 mm was successfully blocked using a concentration of 4% of HSPPG with a particle size of 1000 μm. The blocking strength achieved was 8.06 MPa. The results of these experiments, as well as the observed filling and plugging state of HSPPG in steel fractured cores, indicated that HSPPG possesses the properties of water absorption, swelling, and extrusion filling. These attributes facilitate the effective formation of a dense blocking layer within the fracture space, exhibiting excellent pressure-bearing capacity. In conclusion, the HSPPG developed in this study represents an advanced swellable granular plugging agent with excellent swelling capacity and structural strength at high temperatures. It offers an ideal solution to mitigate drilling fluid loss from fractured formations under high-temperature and high-salinity conditions.

Pattern transition of flow dynamics in a highly water-absorbent granular bed

An aqueous sodium chloride solution was injected at a controlled rate into a granular bed in a quasi-two-dimensional cell. The granular bed was made of dried, highly water-absorbent gel particles whose swelling rate was controlled by the salinity of the injected fluid. At a high salinity level (low swelling rate), high injection rate, and short timescale, the injected fluid percolated between the gel particles in an isotropic manner. Meanwhile, at a low salinity level (high swelling rate), low injection rate, and long timescale, the gel particles clogged the flow path, resulting in anisotropic branch-like structures of the injected fluid front. The transition of the injection pattern could be understood based on the ratio of the characteristic timescales of swelling and injection. Moreover, the clogged pattern showed an oscillatory pressure drop whose amplitude was increased with higher salinity. Such an oscillatory behavior observed in an injection process in swelling gel particles may be relevant in geological situation, such as fluid migration underground.

Heat-induced lupin-whey protein emulsion-filled gels: Microstructural and rheological insights

This work investigates the rheological properties of lupin-whey emulsion-filled gels (EFGs) formed using a pilot scale plate heat exchanger. Samples were prepared with either lupin, whey, or a lupin-whey stabilized emulsion, mixed in a whey protein continuous phase. While whey protein in the continuous phase was mainly responsible for the formation of a primary gel network, differences were observed depending on the droplet-whey protein matrix interactions. Full or partial replacement of interfacial proteins with lupin proteins resulted in softer, more ductile gels. Amplitude sweeps showed that the structure was not only affected by the interactions between the droplets and the continuous network, but also by the droplet distribution within the matrix. This work demonstrates the importance of fine tuning the interactions and the distribution of oil droplets within the gel, as these properties will lead to structural heterogeneity at the micro-scale, causing profound differences in the rheological properties. Finally, continuous heating led to stiffer, more particulate gels compared to quiescent conditions, but similar mechanisms underpinned gel formation. Thus, it is demonstrated that the design of the interactions can be screened using an in situ rheometer, although the rheological properties are affected by the shear effect of the plate heat exchanger.

Progress of Research into Preformed Particle Gels for Profile Control and Water Shutoff Techniques.

Gel treatment is an economical and efficient method of controlling excessive water production. The gelation of in situ gels is prone to being affected by the dilution of formation water, chromatographic during the transportation process, and thus controlling the gelation time and penetration depth is a challenging task. Therefore, a novel gel system termed preformed particle gels (PPGs) has been developed to overcome the drawbacks of in situ gels. PPGs are superabsorbent polymer gels which can swell but not dissolve in brines. Typically, PPGs are a granular gels formed based on the crosslinking of polyacrylamide, characterized by controllable particle size and strength. This work summarizes the application scenarios of PPGs and elucidates their plugging mechanisms. Additionally, several newly developed PPG systems such as high-temperature-resistant PPGs, re-crosslinkable PPGs, and delayed-swelling PPGs are also covered. This research indicates that PPGs can selectively block the formation of fractures or high-permeability channels. The performance of the novel modified PPGs was superior to in situ gels in harsh environments. Lastly, we outlined recommended improvements for the novel PPGs and suggested future research directions.

Development and evaluation of lysine-crosslinked re-crosslinkable particle gel for water control in high-temperature reservoirs

Preformed particle gel (PPG) treatment is a cost-effective technology for controlling excessive water production. However, PPG exhibits limited plugging efficiency when dealing with open fractures at high temperatures. This paper reports a novel environmentally friendly, high-temperature resistant re-crosslinkable PPG (EF-HT-RPPG). The polymer backbone of EF-HT-RPPG is methylene bisacrylamide crosslinked poly (acrylamide-co N-vinylpyrrolidone). The secondary crosslinker is pre-embedded during the synthesis process, and the hydrated gel particles can reform a bulk gel at high temperatures through chemical re-crosslinking between polymer chains and the secondary crosslinker which is lysine. This study investigated the swelling, re-crosslinking behavior, hydrolytic thermal stability, and plugging performance of the EF-HT-RPPG. Bottle tests were conducted to determine the swelling kinetics, re-crosslinking time, and thermal stability data. The plugging efficiency was assessed using a fracture model. EF-HT-RPPG could re-crosslink at 80–130 °C within a reasonable time. The storage modulus (G′) of the re-crosslinked gel with a swelling ratio of 10 was measured at 477 Pa. Additionally, gels prepared in Ekofisk formation water remained stable at 130 °C for over 350 days. The plugging test demonstrated that EF-HT-RPPG could be readily injected into the fracture, with a water breakthrough pressure gradient of 70 psi/ft.

Laboratory-scale characterization of slow-release permanganate gel (SRP-G) for the in-situ treatment of chlorinated-solvent groundwater plumes

Significant challenges remain for the remediation of chlorinated-solvent plumes in groundwater, such as trichloroethene (TCE) and tetrachloroethene (PCE). A novel slow-release permanganate gel (SRP-G) technique may show promise for the in-situ treatment (remediation) of chlorinated contaminant plumes in groundwater. A series of laboratory experiments were conducted to characterize the primary physical factors that influence SRP-G gelation processes to optimize SRP-G performance for plume treatment. Specifically, experiments were conducted to quantify gel zeta potential, particle size distribution, and viscosity to determine SRP-G gelation characteristics and processes. These experiments tested various concentrations of two SRP-G amendment solutions (NaMnO4 and KMnO4) prepared with 30-wt.% and 50-wt.% colloidal silica to determine such influences on zeta potential, particle size distribution, and viscosity. The results of this study show that SRP-G solutions with low zeta potential and relatively high pH favor more rapid SRP-G gelation. The concomitant interaction of the predominantly negatively charged colloidal silica particles and the positively charged dissociated cations (Na+ and K+) in the SRP-G solution had the effect of stabilizing charge imbalance via attraction of particles and thereby inducing a greater influence on the gelation process. Gel particle size distribution and changes in viscosity had a significant influence on SRP-G solution gelation. The addition of permanganate (NaMnO4 or KMnO4) increased the average particle size distribution and the viscosity of the SRP-G solution and decreased the overall gelation time. SRP-G amendments (NaMnO4 or KMnO4) prepared with 50-wt.% colloidal silica showed more effective gelation (and reduced gelation time) compared to SRP-G amendments prepared with 30-wt.% colloidal silica. Under the conditions of these experiments, it was determined that both the 7-wt.% NaMnO4 solution and 90 mg/L KMnO4 solution using 50-wt.% colloidal silica would be the optimal injection SRP-G solution concentrations for this in-situ treatment technique.

Cd(II)-based complex loaded with drug doxorubicin hydrogels against leukemia and reinforcement learning

A new 3D metal–organic frameworks [Cd6(L)4(bipy)3(H2O)2·H2O] (1) was gained by employing Cd(II) and organic ligand [H3L = 4,4′,4′′-(benzene-1,3,5-triyltris(oxy))tribenzoic acid)benzene acid; bipy = 4,4′-bipyridine] in the solvothermal condition, which has been fully examined via single-X ray diffraction, FTIR and elemental analysis and so on. Using natural polysaccharides hyaluronic acid (HA) and carboxymethyl chitosan (CMCS) as raw materials, we successfully prepared HA/CMCS hydrogels and observed their internal micromorphology by scanning electron microscopy. Using doxorubicin (Dox) as a drug model, we synthesized a novel metal gel particle loaded with doxorubicin, and their encapsulation and release effects were studied using fluorescence spectroscopy, followed by further investigation of their components through thermogravimetric analysis. Based on this, the therapeutic effect on leukemia was evaluated. Finally, an enhanced learning method for automatically designing new ligand structures from host ligands was proposed. Through generative modeling and molecular docking simulations, the biological behavior of the host and predicted cadmium complexes was extensively studied.

PH dominates the formation of ginkgo seed protein and whey protein composite gels

This study aimed to investigate the impact of pH on gelation of ginkgo seed protein isolate (GSPI) and whey protein isolate (WPI). The GSPI-WPI composite gels were made by heating a mixture of 12% (w/v) GSPI and 12% (w/v) WPI in equal parts at 90 °C for 30 min at different pHs. Hardness, springiness, and water holding capacity (WHC) of the composite gels at pH 7.0, 8.0 were improved due to formation of a compacted network by disulfide crosslinking. GSPI-WPI formed weak, particulate gels at pH 3.0 with poor WHC. At pH 6.0, the formation of hydrogen bonding improved the rheology of the composite gels. In short, pH is an important quality determinant of the GSPI-WPI composite gels, which provides a basis for gel modification and application in food.

Development of Agar-Based Preformed Particle Gel for Water Control in High-Salinity Reservoirs

Development of Agar-Based Preformed Particle Gel for Water Control in High-Salinity Reservoirs

Nanogranular nature of the CSH gel

Hydration of cementitious materials is accompanied by the formation of calcium hydrosilicates (CSH). Accordingly, the hydration process is completed in the early, middle and late periods, leading to the formation of two types of CSH phases: low density (LD) and high density (HD). Using the nanoindentation method, it was explained nanogranular nature of the CSH gel, which is due to the contact forces of the CSH gel particles for these phases.

Experimental investigation and modeling of the impact of random packings on mass transfer in fluidized beds

This study investigates the impact of two novel settings of bubbling fluidized beds equipped with random metal packings on the mass transfer. To do this, a comprehensive approach is applied that integrates experiments and modeling and explores the relevance of the different underlying mechanisms involved in interphase mass transfer in fluidized beds. Firstly, the mass transfer of water from moisturized silica gel particles to dry air is studied in both a packed-fluidized bed and a freely bubbling bed with no packing. The experimental set-up consists of a cylindrical bubbling fluidized-bed column with an inner diameter of 22 cm. Silica-gel particles with a mean particle diameter of 797 μm are used as bed material. The total bed amount ranges from 4 to 8 kg, while the fluidization number (F) varies between 1.7 and 2.3. Two types of packing, RMSR (stainless steel thread saddle rings) and Hiflow (stainless steel pall rings) are examined and compared to the reference case of a bubbling bed with no packing. The height of the packed section is maintained at 60 cm. The results show that, at all operating conditions, the use of packings enhances the amount of desorbed water in the fluidized bed. The increase is up to 17%, as compared to the bed without packing. The effect is believed to be inhibition of bubble growth in the packed-fluidized bed. To study this further, a mass-transfer model is introduced to analyze the different mass-transfer steps (intra-particle, particle surface to emulsion gas, and emulsion gas to bubble gas) in packed-fluidized beds compared to beds with no packing. TGA experiments are applied to describe the intra-particle mass transfer through a desorption kinetic model. Model analysis shows that the main resistance for mass transfer occurs across the bubble-emulsion boundary. The calculated value of the mass transfer coefficient for this, Kb, at reference conditions (6 kg of silica gel and F = 2.3) is 7.6e-5 s−1 with packings (in average) and 6.2e-5 s−1 without packings, i.e. a 23% improvement in the governing mass-transfer coefficient.

Effect of tremella polysaccharides on the quality of collagen jelly: insight into the improvement of the gel properties and the antioxidant activity of yak skin gelatin.

The present study aimed to investigate the effects of tremella polysaccharides on the gel properties and antioxidant activity of yak skin gelatin with a view to improving the quality of collagen jellies. The preparation of composite gels were performed by yak skin gelatin (66.7 mg mL-1) and tremella polysaccharides with different concentrations (0, 2, 4, 6, 8 mg mL-1), and finally the collagen jelly was prepared by composite gel (yak skin gelatin: 66.7 mg mL-1; tremella polysaccharides:6 mg mL-1) with the best performance. Tremella polysaccharides not only improved the hardness, springiness, gel strength, water holding capacity and melting temperature of yak skin gelatin, but also enhanced the composite gel's scavenging activity against ABTS radicals, DPPH radicals, O2 and OH radicals. The filling of tremella polysaccharides into the gelatin network increased the number of crosslinking sites inside the gel, which resulted in the gel network structure becoming dense and orderly. The gel particles became finer and more uniform, and the thermal stability was improved. Furthermore, the sensory score of commercially available gelatin jelly decreased more rapidly during storage compared to the composite gel jelly. The gel properties and antioxidant activity of yak skin gelatin were improved by adding tremella polysaccharides, and then the quality and storage properties of the jelly were improved, which also provided technical reference for the development of functional gel food. © 2024 Society of Chemical Industry.

Toward Modeling the Structure of Electrolytes at Charged Mineral Interfaces Using Classical Density Functional Theory.

The organization of water molecules and ions between charged mineral surfaces determines the stability of colloidal suspensions and the strength of phase-separated particulate gels. In this article, we assemble a density functional that measures the free energy due to the interaction of water molecules and ions in electric double layers. The model accounts for the finite size of the particles using fundamental measure theory, hydrogen-bonding between water molecules using Wertheim's statistical association theory, long-range dispersion interactions using Barker and Henderson's high-temperature expansion, electrostatic correlations using a functionalized mean-spherical approximation, and Coulomb forces through the Poisson equation. These contributions are shown to produce highly correlated structures, aptly rendering the layering of counterions and co-ions at highly charged surfaces and permitting the solvation of ions and surfaces to be measured by a combination of short-range associations and long-ranged attractions. The model is tested in a planar geometry near soft, charged surfaces to reproduce the structure of water near graphene and mica. For mica surfaces, explicitly representing the density of the outer oxygen layer of the exposed silica tetrahedra allows water molecules to hydrogen-bond to the solid. When electrostatic interactions are included, water molecules assume a hybrid character, being accounted for implicitly in the dielectric constant but explicitly otherwise. The disjoining pressure between approaching like-charged surfaces is calculated, demonstrating the model's ability to probe pressure oscillations that arise during the expulsion of ions and water layers from the interfacial gap and predict strong interattractive stresses that form at narrow interfacial spacing when the surface charge is overscreened. This interattractive stress arises not due to in-plane correlations under strong electrostatic coupling but due to the out-of-plane structuring of associating ions and water molecules.

Investigation on coupling deposition and plugging of hydrate and wax in gas–liquid annular flow: Experiments and mechanism

The coupling deposition and plugging caused by hydrate formation and wax precipitation during the development of deep water natural gas resources bring new industrial challenges and theoretical difficulty. We designed a single-pass pipeline with two types to investigate deposition behavior and systematically performed the coupling deposition and plugging of hydrate and wax experiments in gas–liquid annular flow. The experimental results illustrate that the single solid phase of hydrate is covered layer sheet deposition, while the coupling solid phase of hydrate and wax is bulk aggregations arch bridge deposition. Meanwhile, the natural eddy zone in reducing pipeline accelerates coupling solid particles deposition. Our finds provided the first knowledge on the double effect that wax crystals inhibit particles adhesion and gel network increases aggregations arch bridge blockage. For the low water content in emulsion system, the gel network provides gathering place for hydrate particles, and the arch bridge structure formed by aggregations accelerates the pipeline blockage. The plugging time is shortened by up to 72.6% with the wax concentration increase from 0 wt% to 3 wt%. For the high water content in emulsion system, the majority of wax crystals adsorbed on the hydrate particles and reduce particles cohesion force, which increase the plugging time. Combined with the microscopic morphology evolution perspective of hydrate particles coupled wax, the coupling deposition of hydrate and wax in gas–liquid annular flow has four stages: gas–liquid flow, coupling solid phase formation, coupling solid phase deposition and sloughing, and coupling solid phase plugging. This study can provide theoretical support and design basis for flow assurance program of deep water gas fields and low temperature natural gas transportation pipelines.

Effect of Starch Types on the Textural and Rehydration Properties of Extruded Peanut Protein Pore Gel Particles.

In this study, the effect of different starches from corn, potato and pea containing varying amylose/amylopectin ratios on the textural and rehydration properties of extruded peanut protein gel particles were investigated. Results showed that textural and rehydration properties of peanut protein extruded with corn starch, potato starch and amylopectin are slightly inferior to those of peanut protein with pea starch extrudates. The addition of pea starch led to an increase in the pore structure of the peanut protein extrudates and improved their water absorption index, simultaneously reducing the hardness and density. Pea starch, as a natural water-absorbing expansion material, helped peanut protein to form cross-linked gel polymers that bind more water molecules, in addition to further polymerization with peanut protein, which made the protein secondary structure became disordered. These changes directly affected the textural properties of the extrudates. In addition, the blended system of starches and peanut protein tended to form more elastic solids, which affected the expansion of the extrudates. These findings indicate that starch can effectively improve the poor expansion of proteins, making it suitable for use in the production of plant protein-based foods.