Gel Particles Research Articles

Impact of composition and salinity on swelling and gel strength of poly (acrylamide-co-acrylic acid) preformed particle gel

The effects of various material compositions and reservoir environments on the ultimate strength and swelling kinetics of a commercial preformed particle gel (PPG) have been investigated. This study used different ratios of acrylamide and acrylic acid copolymers with a specific crosslinker concentration. Results have indicated that increasing the acrylic acid proportion enhances the PPGs’ ability to swell but weakens their network structure. In contrast, increasing the crosslinker content decreases the swelling ratio and increases the gel strength. The highest equilibrium swelling capacity among the six preformed particle gel samples was obtained for PPG2, which has the highest acrylic acid amount and the lowest crosslinker content, with a swelling ratio of 2400 g/g in deionized water and 59.8 g/g in brine 1 (67535.8 mg/l). On the contrary, PPG5, with the lowest acrylic acid and highest crosslinker content, has a swelling capacity of 239 g/g and more than 17 g/g in distilled and brine 1, respectively. Yet, PPG5 has the highest swollen gel strength of 615.5 Pa in deionized water and 3344 Pa in brine 1. The PPGs’ swelling ratios showed stepwise improvements along with increasing temperature, notably after 50 °C, yet, the storage modulus (G′) was negatively affected. The PPGs revealed the highest swelling behavior in pH 6–8, decreasing dramatically in more acidic and basic conditions. The swelling ratios of the PPGs in brine 1 at 50 °C were between 12 and 32 g/g, having strengths in the range of 566–5508 Pa, depending on the crosslinker ratio. The PPGs also demonstrated the ability to compete with other commercial PPGs as they have shown physical and thermal stability when aging at 50 °C, specifically those with high crosslinker content (PPG5).

Fabrication of pea protein gels with modulated rheological properties using high pressure processing

High pressure processing (HPP) as a non-thermal food preservation technology has recently received growing interest in protein processing. In the present study, the impact of high-pressure level, treatment time, protein concentration, and sample pH on the pea protein gel microstructure and strength were systematically investigated, as well as the protein conformation study, and the gel rheological and dissolution tests. A minimum of 10% and 15% (w/v) protein concentration was required for self-standing pea protein gel formation under 600 MPa and 300 MPa, respectively, at ambient temperature. The pH played an important role in affecting the gel microstructures and properties using HPP treatment. Particulate gels with compact structures and high mechanical strength up to 130 kPa were obtained at pH 5 mainly stabilized by hydrophobic interactions. Whereas fine-stranded gels mainly stabilized by hydrogen bonding with good elasticity and high water-holding capacity were formed at pH 7. The pH, HPP pressure level, and duration have been modulated to prepare a series of pea protein gels to mimic the texture of jelly, pudding, and tofu products. The tunable capacity using HPP makes pea protein a potential gelling ingredient in a wide range of food applications as a substitute for animal or soy protein. Furthermore, the gels treated with pH-shifting followed by HPP showed high freeze-thaw stability with a minimum syneresis level of 15% after two freeze-thaw cycles, demonstrating their potential to be used in frozen food products. Considering the advantages such as improved nutritional quality and extended shelf life compared to thermal technologies, HPP could be a promising non-thermal technique for the fabrication of pea protein gels with tunable rheological and mechanical properties to meet consumer needs for diversified texture and sensory quality.

P-072 Efficacy of a microfluidic chip technology for sperm selection in intrauterine insemination cycles

Abstract Study question Is there an advantage of using a new sperm selection method by microfluidics (MFSS) over standard density gradient (DG) for couples undergoing intrauterine insemination (IUI)? Summary answer MFSS reduced sperm processing time and selected spermatozoa with greater progressive motility and superior genomic integrity, suggesting a better clinical outcome than DG. What is known already The most conservative, cost-effective reproductive treatments for infertile couples are timed intercourse and IUI. The latter is generally performed using DG to enrich and purify the most motile spermatozoa; it requires technician effort and skills as well adequate processing time. Moreover, during DG centrifugation, spermatozoa are exposed to potentially harmful silica gel particles and eventual reactive oxygen species (ROS). The recent availability of a microfluidic chamber has been proposed as a method to safely process spermatozoa in an expedited manner while reducing human intervention. Therefore, we decided to test MFSS in a laboratory that executes over 2,000 IUI cycles/year. Study design, size, duration Since September 2022, 93 couples underwent 103 IUI-MFSS. Post-processing semen parameters and clinical outcomes were compared with those of 103 age-matched couples who underwent 103 IUI-DG during the same period. To confirm findings, 45 couples undergoing their first IUI-MFSS had post-processing semen parameters and clinical outcomes compared with 45 first-time IUI-DG couples, serving as a matched control. Finally, within the same 66 couples, outcomes were compared between their initial IUI-DG cycle and a subsequent IUI-MFSS. Participants/materials, setting, methods Men had normal raw semen parameters according to the most recent WHO criteria. DG was performed according to WHO21 guidelines, while MFSS as per manufacturer protocol (ZyMōt® Multi 850µL). Stimulation protocols were similar between all patients. Before and after processing, volume, concentration, and motility were compared between the two processing methods. Sperm chromatin fragmentation (SCF) was assessed by TUNEL (In Situ Cell Death Detection Kit; normal threshold,≤15%). For all comparisons, +bHCG and clinical pregnancy (+FHB) were compared retrospectively. Main results and the role of chance Ninety-three couples (maternal age,37.3±4; paternal age,39.2±6) underwent 103 IUI-MFSS cycles and were matched for age and abstinence days (1–4d) to 103 IUI-DG patient/cycles. IUI-DG and IUI-MFSS yielded 0.5±0mL volume, 76.8±40x106/mL and 41.3±26x106/mL concentrations, and 89.4±3% and 98.3±1% motility, respectively (P<0.001). IUI-DG resulted in a 20.4% +bHCG (21/103) and 15.5% +FHB (16/103). IUI-MFSS yielded a 19.4% +bHCG (20/103) and 16.5% +FHB (17/103). Forty-five couples (maternal age,36.8±4; paternal age,37.8±6) who underwent their first IUI with MFSSwere matched to a first-time IUI-DG cohort with similar semen parameters and abstinence. IUI-DG led to a 0.5±0 mL volume, 77.3±43x106/mL concentration, and 90±2% motility. IUI-MFSS yielded a lower concentration (45.6±27x106/mL), but a remarkable increase in motility (98.3±1%) (P<0.001). IUI-DG yielded a 13.3% +bHCG (6/45) and an 8.9% +FHB (4/45). IUI-MFSS yielded a 15.6%(7/45) +bHCG and an 11.1% +FHB (5/45). Finally, we assessed 66 couples who underwent IUI-DG and subsequently IUI-MFSS. IUI-DG resulted in a 77.5±39x106/mL concentration and 89.0±3% motility, while IUI-MFSS resulted in a lower concentration (36.9±21x106/mL), but an enhanced motility (98.3±1%)(P<0.001). IUI-DG yielded a 15.2% +bHCG (10/66) and an 8.9% +FHB (5/66), while IUI-MFSS yielded a 15.2% +bHCG (10/66); all became clinically pregnant. In all comparisons, SCF was 6.5±3% in raw samples, became 4.7±2% after DG, and negligible after MFSS at 0.8±0.6%(P<0.001). Limitations, reasons for caution IUI-MFSS cycles yielded a higher number of progressively motile spermatozoa with superior genomic integrity and a comparable clinical outcome to IUI-DG. This study came at a higher cost due to the device and offered only preliminary results. Therefore, it needs to be repeated in a larger study population. Wider implications of the findings DG is time consuming, labor intensive, and its outcome is technician-dependent. While reducing exposure to chemicals and ROS, MFSS grants higher motility and superior genomic integrity. If a greater clinical outcome is confirmed in a larger cohort, MFSS may prove to be a superior sperm processing method for IUI. Trial registration number not applicable

Coalescence Behavior of a CO2-Resistant Dispersed Particle Gel (SCDPG) in Supercritical CO2

The reservoir heterogeneity and unfavorable oil/gas mobility ratio lead to gas channeling and low CO2 sweep efficiency during CO2 flooding in low-permeability reservoirs. A dispersed particle gel (DPG) could migrate deep into the reservoir and coalesce, which has the potential for CO2 gas channeling control. In this work, a CO2-resistant bulk gel was prepared by a cross-linking reaction of a copolymer with acid-resistant groups and catechol–hexamethylenetetramine, which exhibited excellent CO2 resistance. Subsequently, a CO2-resistant dispersed particle gel (SCDPG) used in supercritical CO2 was successfully prepared from the CO2-resistant bulk gel by a high-speed mechanical shearing method. Meanwhile, the coalescence behavior of the SCDPG particles in supercritical CO2 was systematically investigated from the microstructure, particle size, ζ potential, and mechanical strength. The results showed that the SCDPG particles were dispersed in the liquid phase as a single particle. SCDPG had good dispersion stability during storage and injection. In supercritical CO2, the dispersion stability of SCDPG decreased, and the particles coalesced with each other to form aggregates with a stereostructure instead of degradation. The SCDPG particles maintained high mechanical strength, showing the long-term effectiveness for gas channeling control during CO2 flooding. In addition, the interparticle force of SCDPG particles was measured by an AFM colloid probe based on the reservoir characteristics. The interparticle force of SCDPG particles changed from repulsion to adhesion with increasing salinity. At a salinity of 0.5 mol/L, the adhesion force increased with the increase of temperature and the decrease of the pH value. According to the type of intermolecular force, the adhesion force originated from the hydrogen bond, π–π stacking, and cation−π interaction. This work provides theoretical support for the field application of the dispersed particle gel and promotes the development of utilization of carbon dioxide in oilfields.

92-OR: The Survival and Function of Whole or Dissociated Islet Transplants Are Improved by Immunomodulatory Microporous Annealed Particle (MAP) Gel

The aim was to investigate if MAP gel can support the function of whole islets or dissociated islet cells, and improve transplantation under kidney capsule or within the epididymal fat pad. A) Whole or dissociated BL/6 islets were transplanted into syngeneic diabetic recipients in the presence or absence of MAP gel. 100 islets were transplanted under the kidney capsule (n=6/group). Mice receiving transplant within the fat pad were divided into 6 groups (n=2/group): 300 whole islets; 400 dissociated islets; MAP gel alone; and 200, 300 or 400 dissociated islets with MAP gel. Blood glucose (BG) was measured daily. B) MAP gel or NP gel was transplanted within the fat pad of NOD mice (n=4/group) to analyze the immune response. Graft-containing fat pad was excised 6 weeks post-transplantation and analyzed for cytokines by flow cytometry. Our results indicated that transplantation of dissociated islets and MAP gel under the kidney capsule permanently restored normoglycemia within 18 days. In contrast, uncoated dissociated islet cells failed to reverse diabetes. Treatment efficacy continued 40 days post-transplantation, the entire period of observation. At Day 30, average BG was 163±38mg/dL. Diabetic mice transplanted with dissociated islet cells without MAP gel remained hyperglycemic. Transplantation of 400 dissociated islet cells with MAP gel within the fat pad also achieved normal BG levels that continued 44 days post-transplantation, the period of observation. In contrast, transplantation of MAP gel, or 300 whole islets, or dissociated islets alone into the fat pad, failed to reverse diabetes. An upregulation of IL-10 and downregulation of IL-6 was observed only in the graft microenvironment of the MAP gel group, validating the immunomodulating capacity of MAP gel. To conclude, MAP gel can promote transplantation outcomes under the kidney capsule or within the fat pad by improving the survival and function of both, whole and dissociated islets. Disclosure M.Ma: None. C.A.Roosa: None. D.R.Griffin: Board Member; Tempo Therapeutics. K.L.Brayman: None. P.Chhabra: None. Funding LaunchPad for Diabetes Innovation Fund (GF004946); LaunchPad for Diabetes Ignite Program (169098)

Dispersion and Flow Characteristics of Super-Hydrophobic Marshmallow-Like Gel Particles in CMC Solution for Latent Heat Transportation

Dispersion and Flow Characteristics of Super-Hydrophobic Marshmallow-Like Gel Particles in CMC Solution for Latent Heat Transportation

Preparation, Properties and Therapeutic Effect of a TPL Nanoparticle Thermosensitive Gel for Intra-Articular Injection.

Most injectable preparations for the articular cavity are solution-type preparations that are frequently administered because of rapid elimination. In this study, triptolide (TPL), an effective ingredient in the treatment of rheumatoid arthritis (RA), was prepared in the form of a nanoparticle thermosensitive gel (TPL-NS-Gel). The particle size distribution and gel structure were investigated by TEM, laser particle size analysis and laser capture microdissection. The effect of the nanoparticle carrier material PLGA on the phase transition temperature was investigated by 1H variable temperature NMR and DSC. The tissue distribution, pharmacokinetic behavior, four inflammatory factors and therapeutic effect were determined in a rat RA model. The results suggested that PLGA increased the gel phase transition temperature. The drug concentration of the TPL-NS-Gel group in joint tissues was higher than that in other tissues at different time points, and the retention time was longer than that of the TPL-NS group. After 24 days of administration, TPL-NS-Gel significantly improved the joint swelling and stiffness of the rat models, and the improvement degree was better than that of the TPL-NS group. TPL-NS-Gel significantly decreased the levels of hs-CRP, IL-1, IL-6 and TNF-α in serum and joint fluid. There was a significant difference between the TPL-NS-Gel and TPL-NS groups on Day 24 (p < 0.05). Pathological section results showed that inflammatory cell infiltration was lower in the TPL-NS-Gel group, and no other obvious histological changes were observed. Upon articular injection, the TPL-NS-Gel prolonged drug release, reduced the drug concentration outside the articular tissue and improved the therapeutic effect in a rat RA model. The TPL-NS-Gel can be used as a new type of sustained-release preparation for articular injection.

A novel fluorescent dispersed particle gel: Fluorescence monitoring method and breakthrough flow channel identification

The breakthrough flow channel generated by formation heterogeneity has severely restricted oil recovery improvement, and its identification and control methods have received extensive attention. In this study, we developed a novel fluorescent dispersed particle gel (FDPG) for identifying and regulating breakthrough flow channels based on the dispersed particle gel (DPG). A copolymer of acryloyl fluorescein and acrylamide (PAMAF) was synthesized by free-radical copolymerization for the preparation of the FDPG. The fluorescence properties and identification method of FDPG were systematically investigated. The results showed that the FDPG had stable fluorescence properties, and its concentration showed a linear relationship with fluorescence intensity. The excitation and emission wavelengths of FDPG fluorescence fall within the interval that can avoid the influence of crude oil on its detection. FDPG can accurately reflect the migration of particles in the formation and avoid the chromatographic separation effect. FDPG has excellent injection and migration properties and can effectively control the high permeability layer after ageing. By analysing the output of the FDPG, breakthrough flow channels that exist between formation layers and within well groups can be effectively identified. FDPG provides a promising approach for identifying breakthrough flow channels and monitoring particle profile control agents.

Real-time monitoring of casein gel microstructure during simulated gastric digestion monitored by small-angle neutron scattering

The evolving structure of protein-based foods during the digestion process is critical to the release of nutrients. However, traditional in vitro monitoring of the gel micro- and nano-structure during digestion involves analysing sample aliquots taken at different digestion time periods. This can pose issues for some gels, such as casein-based gels, as they are sensitive to sample manipulation and environmental changes. Herein, a newly developed flow setup was utilised to monitor (at the micro- and nano-length scales) the gel protein network of rennet-induced (RG) and transglutaminase-induced acid gels (TG) in situ and in real-time during simulated gastric digestion using ultra-small and small-angle neutron scattering (USANS and SANS). The proteolysis kinetics of the gels were investigated at two different pepsin enzyme concentrations (2000 and 8000 U mL-1) and in two different solvent environments (H2O and D2O). Results indicate that the flowing in situ system had a greater effect on the microstructural breakdown of TG relative to the acid-sensitive RG, compared to the traditional static method. This is the first in situ digestion study observing the structural changes of large protein gel particles with USANS or SANS in real-time. Our findings advance the understanding of the kinetics of casein gel disintegration under simulated conditions of gastric digestion relating to pepsin enzyme concentration and solvent environment, and critically, the utilisation of a new in situ and real-time setup for neutron studies.

MagNeed – Needle-Shaped Electromagnets for Localized Actuation Within Compact Workspaces

Electromagnetic actuation of micro-/milli-sized agents has traditionally relied on large electromagnets positioned at considerable distances from the agents. As a result, the electromagnets consume kilowatts of power to overcome the limited generation of magnetic field gradients. Miniaturized electromagnets offer an alternative approach for reducing power consumption via localized actuation of micro-/milli-sized agents. Typically, the generation of magnetic field gradients in the vicinity of a miniaturized electromagnet is comparable with traditional electromagnetic actuation systems. Miniaturized electromagnets can be positioned near target sites in microfluidic channels or <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ex vivo</i> vasculatures. Thereby, localized trapping and actuation of magnetic micro-/milli-sized agents are carried out. This study introduces MagNeed – an electromagnetic actuation system composed of three needle-shaped electromagnets (NSEs). MagNeed can determine compact workspaces by positioning the NSEs at different spatial configurations. Each NSE generates magnetic field gradients (up to 3.5 T/m at 5 mm from the NSE tip axis) while keeping a maximum power consumption (0.5 W) and temperature ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$&lt; $</tex-math></inline-formula> 42 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{o}$</tex-math></inline-formula> C). MagNeed is complemented by a framework that reconstructs the pose of the NSEs. Experiments test MagNeed and framework on a transparent Teflon tube (5 mm inner diameter). MagNeed demonstrates localized trapping and actuation of a 1 mm NdFeB bead against a flow of water and silica gel particles (1-3 mm diameter).

Solar Air Conditioning System

Abstract: Rotary desiccant wheel are used to regulate the relative humidity of air streams. These are commonly integrated into heating ,ventilation and air conditioning unit to reduce the relative humidity of incoming ventilation air. Passive ventilation system are able to deliver adequate ventilation air but cannot control the humidity of the incoming air. To overcome this, the honeycomb water structure of rotary desiccant wheel was redesigned. In addition to this, the temperature of the regeneration air for desorption was lowered. Cooling pads were introduced in between the spokes of the wheel and filled with silica gel particles to form a rotary desiccant wheel. Computational fluid dynamics (CFD) model of the design was validated using experimental data.

Modification of DNA by Genetic Engineering

Abstract: Genetic engineering modifies a living organism's DNA in a lab. Altering a single DNA base pair (A-T or C-G), deleting or inserting DNA, or employing all three approaches together may accomplish this purpose. Inserting a gene with a desired characteristic into a separate species' genome is one use of genetic engineering. Genetic modification has been utilized to develop cancer drugs, brewing yeasts, GM crops and animals, and other commercial and scientific items. Probe tests on genomic DNA and RNA can identify certain sequences. Short DNA probes may be detected using radioactive or fluorescent reagents. Gel electrophoresis separates different-sized nucleic acid fragments. Blotting transfers gel particles to nylon membranes. Radioactive or fluorescent probe sequences may identify trans-membrane nucleic acid components. Southern blotting transfers DNA to a nylon membrane, whereas northern blotting transfers RNA. Northern blots identify gene expression, whereas southern blots examine nucleotide patterns. Below is a reversed gel electrophoresis image. Gel electrophoresis shows the band is concentrated in two locations. After PCR amplification, the snapshot was taken. The band suggests a substantial quantity of plasmid DNA in the sample. The outside area also has a few more distinct bands. This means the bands are localized and accumulation is lesser.

Experimental study on the plugging and profile control of preformed particle gels in high temperature and salinity reservoir

AbstractA novel modified polysaccharide composite preformed particle gel (MCPG) was synthesized as a profile control agent to improve the situation of high water cut and low oil recovery. Then, the structure of MCPG was characterized by Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), and environmental scanning electron microscope (ESEM). Subsequently, the impact of MCPG on enhanced oil recovery was investigated through nuclear magnetic resonance (NMR) and core displacement experiments. The results of FTIR, XRD, and ESEM indicate that monomers have been successfully intercalated into the layered structure of nanoscale sodium bentonite. In the condition of 130°C and salinity of 240,000 mg/L, the value of the swelling ratio and the toughness factor can reach about 30 and 0.87, respectively. The results of nonlinear fitting indicate that the relationship between the resistance coefficient and residual resistance coefficient with the matching coefficient (β) followed a power function, while the blocking water efficiency with β followed an exponential function. When the permeability ratio was as high as 30.58, MCPG still exhibited excellent profile improvement performance. NMR experiments proved that MCPG increased the displacement resistance in large pores and effectively enhanced the displacement efficiency in medium pores and small pores. The oil displacement efficiency in MCPG flooding and subsequent water flooding stages increased by 18.65% and 8.42%, respectively.

Acrylamide preformed particle gels with movable-crosslinking for conformance control

In order to improve the deformation ability of the preformed gel particles (PPGs), the movable-crosslinking structure was introduced into the gel network. Herein, polyrotaxane cross-linkers were synthesized by a three-step method, and acrylamide and polyrotaxane cross-linkers form gel. The structure of polyrotaxane cross-linkers was characterized by IR, HNMR, and X-ray diffraction. The findings demonstrate the successful insertion of vinyl into cyclodextrin, resulting in the formation of crosslinking points. The gel with movable-crosslinking has better deformation ability, and the breaking elongation of gel is 937%, showing excellent deformation ability Through temperature resistance and salt resistance, it shows that the expansion ratio of gel is higher than that of ordinary gel. The injectability of the gel was investigated and the sand pack plugging test was conducted. The injectivity experiment shows that the gel with movable-crosslinking has positive injectivity, can migrate to the depth of the formation, and has excellent water-plugging effect.

Limited concordance of heparin/platelet factor 4 antibody assays for the diagnosis of heparin-induced thrombocytopenia: an analysis of the TORADI-HIT study

BackgroundAnecdotal reports suggest that the correlation between heparin/platelet factor 4 (PF4) antibody assays for the diagnosis of heparin-induced thrombocytopenia (HIT) is limited. ObjectivesTo investigate the correlation between widely used assays and examine possible factors contributing to variability. MethodsThis is a large, prospective cohort study with 10 participating tertiary care hospitals including 1393 patients with suspected HIT in clinical practice. HIT was defined by a positive heparin-induced platelet activation (HIPA) assay (washed platelet reference standard test). Three different immunoassays were used to measure heparin/PF4 antibodies: chemiluminescent immunoassay, enzyme-linked immunosorbent assay, and particle gel immunoassay. Various factors that could influence the assays were examined: sex (male or female), age (<65 years or ≥65 years), unfractionated heparin exposure, presence of thrombosis, cardiovascular surgery, and intensive care unit. Spearman’s correlation coefficients were calculated. Z-scores and diagnostic odds ratios were determined in the aforementioned subgroups of patients. ResultsAmong 1393 patients, 119 were classified as HIT-positive (prevalence, 8.5%). The median 4Ts score was 5 (IQR, 4-6) in patients with HIT compared with 3 (IQR, 2-4) in patients without HIT. Correlations (rs) between immunoassays were weak (0.53-0.65). Inconsistencies between immunoassays could not be explained by further analyses of z-scored test results and diagnostic odds ratios in subgroups of patients. ConclusionThe correlation between widely used heparin/PF4 antibody assays was weak, and key factors could not explain this variability. Standardization of immunoassays is requested to improve comparability.

Study on ultrasonic depolymerization of Si-Ge precipitation in zinc oxide dust leaching process

Under the background of the increasing demand for germanium in high-tech, this paper finds out the mechanism of silicon germanium polymerization precipitation by simulating the leaching process of zinc oxide dust containing germanium. By comparing and analyzing the simulation experiments under ultrasonic and conventional conditions, the mechanism of efficient dispersion and depolymerization of germanium silicon precipitation induced by ultrasonic was found out. The results show that in the leaching process of germanium-containing zinc oxide dust, due to the increase of local pH, some silicon ions in the solution will hydrolyze and polymerize to form silicic acid colloid to adsorb germanium in the solution, causing the loss of germanium 14.81%, resulting in low recovery rate of germanium industry. Ultrasonic wave was introduced in the leaching process, and the shock wave and micro-jet released by ultrasonic cavitation continuously impacted the surface of polysilicate colloid. The germanium adsorbed on the surface of the silicic acid colloid is desorbed, and the large particles of silica gel are depolymerized into small particles of silicic acid, which reduces the adsorption of silica gel on germanium. The loss of germanium under ultrasonic conditions can be reduced by 59.35%. This study can effectively realize the efficient recovery of germanium in zinc oxide dust, and provide process and theoretical basis for the sustainable development of germanium industry.

Ultrasound effects on restricted silica gelation during silica extraction from Pyro-Metallurgical copper slag under acidifying conditions

Pyro-metallurgical copper slag (CS) waste was used as the source material for ultrasound (US) silica extraction under acidification processes with 26 kHz with HCl, HNO3, and H2SO4 at different concentrations at 100, 300, and 600 W. During acidifying extraction processes, US irradiation inhibited silica gel formation under acidic conditions, especially at lower acid concentrations of less than 6 M, whereas a lack of US irradiation led to enhanced gelation. When US stopped, gelation occurred to a considerable degree, suggesting that the gel particle size distribution was aggregated in the 3–400 µm size range. However, with US, the size was mainly in the 1–10 µm range. Results of elemental analysis indicated that US treatment decreased the co-precipitation of other metal ions such as Fe, Cu, and Al sourced from CS for lower acidic medium, whereas the higher concentration medium accelerated silica gelation and the co-precipitation of other metals. With acids of HCl and HNO3, and H2SO4, the gelations were less likely to occur at 6 M and 3 M during US irradiation, but acidic extraction without US was efficient for silica gelation and co-precipitation of other metals in the purified silica. The silica extraction yield with H2SO4 concentration of 3 M was 80% with 0.04% of Fe, whereas the silica product from HCl 6 M had a 90% extraction yield with only 0.08% of Fe impurity. In contrast, even though the non-US system of HCl 6 M had a higher yield at 96%, the final product had 0.5% Fe impurity, which was much higher than the US system. Consequently, the US extraction process was quite noticeable for silica recovery from CS waste.

Experimental Study on Enhanced Oil Recovery of PPG/ASP Heterogeneous System after Polymer Flooding

Following the application of polymer flooding in Daqing Oilfield, the heterogeneity between different layers has intensified, resulting in the formation of more favorable seepage channels and cross-flow of displacement fluids. Consequently, the circulation efficiency has decreased, necessitating the exploration of methods to enhance oil recovery. This paper focuses on experimental research utilizing a newly developed precrosslinked particle gel (PPG) combined with alkali surfactant polymer (ASP) to create a heterogeneous composite system. This study aims to improve the efficiency of heterogeneous system flooding after polymer flooding. The addition of PPG particles enhances the viscoelasticity of the ASP system, reduces the interfacial tension between the heterogeneous system and crude oil, and provides excellent stability. The heterogeneous system has high resistance and residual resistance coefficients during the migration process in a long core model, achieving an improvement rate of up to 90.1% under the permeability ratio of 9 between high and low permeability layers. Employing heterogeneous system flooding after polymer flooding can increase oil recovery by 14.6%. Furthermore, the oil recovery rate of low permeability layers can reach 28.6%. The experimental results confirm that the application of PPG/ASP heterogeneous flooding after polymer flooding can effectively plug high-flow seepage channels and improve oil washing efficiency. These findings hold significant implications for further reservoir development after polymer flooding.

Probing the Effect of Young’s Modulus on the Reservoir Regulation Abilities of Dispersed Particle Gels

The mechanical strength of dispersed particle gels (DPGs), which can be directly characterized by Young's modulus, is an important parameter affecting reservoir regulation performance. However, the effect of reservoir conditions on the mechanical strength of DPGs, as well as the desired range of mechanical strength for optimum reservoir regulation performance, have not been systematically studied. In this paper, DPG particles with different Young's moduli were prepared and their corresponding migration performances, profile control capacities and enhanced oil recovery abilities were studied by simulated core experiments. The results showed that with increase in Young's modulus, the DPG particles exhibited improved performance in profile control as well as enhanced oil recovery. However, only the DPG particles with a modulus range of 0.19-0.762 kPa could achieve both adequate blockage in large pore throats and migration to deep reservoirs through deformation. Considering the material costs, applying DPG particles with moduli within the range of 0.19-0.297 kPa (polymer concentration: 0.25-0.4%; cross-linker concentration: 0.7-0.9%) would ensure optimum reservoir control performance. Direct evidence for the temperature and salt resistance of DPG particles was also obtained. When aged in reservoir conditions below 100 °C and at a salinity of 10 × 104 mg·L-1, the Young's modulus values of the DPG particle systems increased moderately with temperature or salinity, indicating a favorable impact of reservoir conditions on the reservoir regulation abilities of DPG particles. The studies in this paper indicated that the practical reservoir regulation performances of DPGs can be improved by adjusting the mechanical strength, providing basic theoretical guidance for the application of DPGs in efficient oilfield development.

Heat transfer characteristics in turbulent flow and flow patterns of PCM slurry using super-hydrophobic gel particles

An experimental study on the characteristics of heat transfer in turbulent flow and the flow patterns of an organic phase change marerial (PCM) slurry was conducted to investigate the latent heat transportation. As a PCM slurry, the particles of the super-hydrophobic marshmallow-like gel, adsorbing hexadecane on their surface, were dispersed in sodium carboxymethyl cellulose (CMC) solution. Hexadecane is a PCM with a melting point of 17.5 °C, and latent heat of 226.5 kJ·kg−1. For the heat transfer measurement, a double-tube heat exchanger with an inner tube with an inner diameter of 8 mm was used. The results demonstrated that the heat transfer of the marshmallow-like slurry with hexadecane was 1.5 times higher than that of Newtonian fluids. From the pressure drop in the test section, the heat transport efficiency was calculated, which was also higher than that of Newtonian fluids. Furthermore, the flow patterns of the marshmallow-like gel slurries were investigated by varying the CMC concentration and flow velocity. From the results, four patterns of particle dispersion in the flow were observed. The most dispersed flow pattern was observed with all CMC concentrations when the flow velocity was sufficiently high. Based on these results, it was concluded that heat transportation by the marshmallow-like gel slurry is promising.