Carrier Liquid Research Articles

Physical and Chemical Stability of Nanoparticles in Ferrofluid Before and After Impregnation: Implications for Magnetic Pore Fabric Studies

AbstractMagnetic pore fabrics (MPFs) are a promising approach to explore the 3D pore space of rocks. There exist empirical relationships between the orientation, degree, and shape of MPF with pore space geometry and permeability anisotropy. Nevertheless, the precise nature of these relationships remains elusive. A common assumption in MPF studies is that ferrofluid uniformly fills the pore space, establishing a constant nanoparticle density and magnetic properties in space and time. However, this assumption is challenged by observations of particle sedimentation and time‐dependent magnetic properties, which render the quantitative interpretation of MPFs challenging. This study explores the physical and chemical stability of ferrofluid, mobility of particles after impregnation, and the magnetic properties of impregnated rocks over time. Water‐based ferrofluids are physically more stable than oil‐based ferrofluids, though with higher magnetic variability. In impregnated rock, magnetic nanoparticles display a certain degree of mobility, resulting in changes in MPF degree and shape. When ferrofluid is mixed with epoxy, particles are less mobile, though some changes were observed both during polymerization and aging. The susceptibility of ferrofluid‐epoxy mixtures is lower than for ferrofluid and carrier liquid at the same concentration. Interestingly, the susceptibility of impregnated rock increases over time, regardless of the ferrofluid used for the impregnation. Understanding and controlling these processes will enhance the reliability of MPF interpretations and increase the applicability of the method.

Recent developments and emerging trends in hydrogen storage in liquid hydrogen carriers

Recent developments and emerging trends in hydrogen storage in liquid hydrogen carriers

Inhalation toxicity of thermal transformation products formed from e-cigarette vehicle liquid using an in vitro lung model exposed at the Air–Liquid Interface

The increasing use of electronic nicotine delivery systems (ENDS), also known as e-cigarettes, has raised serious public health concerns, particularly regarding certain vaping product additives. The solvent carrier liquid, which consists of a mixture of propylene glycol (PG) and vegetable glycerine (VG), representing the main constituents of e-liquid formulations, have in contrast received little attention in health evaluations due to their apparent harmlessness when ingested; however, they can develop into potential lung hazards when heated, aerosolised and inhaled from ENDS with a user-defined heating profile. To assess the acute toxicity of the respirable aerosol, an effect-based in vitro testing strategy was applied in dependence of the heating power settings in ENDS. Human alveolar epithelial cells (A549) were exposed to vaping aerosol at the air–liquid interface (ALI), flanked by targeted chemical analyses of reactive carbonyl species. An exploratory, semi-automated in vitro exposure system provided evidence of a positive connection between vaporisation temperature and aerosol toxicity. Thermochemical transformation of the solvent leads to the formation of both cytotoxic and genotoxic substances that may disrupt lung homeostasis. Toxicity is therefore not limited to the presence of additives, as most harmful volatiles originate from the solvent itself, ultimately related to the device power output.

Determination of remdesivir in human plasma using (deep eutectic solvent-ionic liquid) ferrofluid microextraction combined with liquid chromatography

A microextraction technique based on ferrofluids was developed for the preconcentration and quantification of Remdesivir in human plasma samples. This method utilized a new type of magnetic colloids created by combining silica-coated magnetic particles with modified ionic liquid and natural hydrophobic deep eutectic solvent as the carrier liquid. The efficiency of the sorption and desorption steps was optimized using a chemometrics approach. Under the optimized conditions, the calibration curve exhibited linearity in the concentration range of 0.5 to 500.0 μg L−1, with a limit of detection and quantification of 0.2 and 0.5 μg L−1, respectively. The method precision was evaluated by assessing intra- and interday precision at three different analyte concentrations, yielding values of 8.9% and 16.8%, respectively. Moreover, the method accuracy fell within the range of 90.9% to 107.5%. This proposed method offers a green and environmentally friendly sample preparation technique for conducting pharmacodynamic, pharmacokinetic, and therapeutic drug monitoring studies of Remdesivir in biological fluids. Importantly, this technique eliminates the need for external energy sources or the use of dispersive solvents, providing a more efficient and sustainable approach.

Thermodynamics of Reversible Hydrogen Storage: Are Methoxy-Substituted Biphenyls Better through Oxygen Functionality?

The reversible hydrogenation/dehydrogenation of aromatic molecules, known as liquid organic hydrogen carriers, is considered as an attractive option for the safe storage and release of elemental hydrogen. The recently reported efficient synthetic routes to obtain methoxy-biphenyls in high yield make them promising candidates for hydrogen storage. In this work, a series of methoxy-substituted biphenyls and their structural parent compounds were studied. The absolute vapour pressures were measured using the transpiration method and the enthalpies of vaporisation/sublimation were determined. We applied a step-by-step procedure including structure–property correlations and quantum chemical calculations to evaluate the quality of thermochemical data on the enthalpies of phase transitions and enthalpies of formation of the studied methoxy compounds. The data sets on thermodynamic properties were evaluated and recommended for calculations in chemical engineering. A thermodynamic analysis of chemical reactions based on methoxy-biphenyls in the context of hydrogen storage was carried out and the energetics of these reactions were compared with the energetics of reactions of common LOHCs. The influence of the position of the methoxy groups in the rings on the enthalpies of the reactions relevant for hydrogen storage was discussed.

Symbiotic effectiveness, abiotic stress tolerance and phosphate solubilizing ability of new chickpea root-nodule bacteria from soils in Kununurra Western Australia and Narrabri New South Wales Australia

AimsTo assess the symbiotic effectiveness, tolerance to abiotic stress factors and phosphate solubilizing ability of new chickpea root-nodule bacteria.MethodsSymbiotic effectiveness, abiotic stress tolerance and phosphate solubilizing ability of ten new chickpea rhizobial strains collected from soils were evaluated using laboratory and glasshouse experiments.ResultsSix of the ten strains were symbiotically efficient with diversity between those and the commercial chickpea strain CC1192. High temperatures significantly affected strain survival in liquid and peat carrier. Peat carrier offered greater protection. Above 37 °C, strain infectivity decreased with no correlation between strain origin and their infectivity after exposure. Three of the new strains and CC1192 produced optimum growth and survival at pH 6.8 and at two lower pH’s of 4.4 and 5.4 were able to neutralize the growth medium while the other seven strains at high pH were able to either neutralize or acidify the growth medium. Strain survival was significantly higher at increased salt concentrations of NaCl compared to CaCl2. At 3% NaCl concentration, 8 strains survived while at 3% CaCl2 only 3 survived. Many strains were resistant to more than one antibiotic. All strains were able to solubilize phosphate. The ratio between the most efficient strain and the least was 3:1.ConclusionsChickpea rhizobia strains sourced from soils in Narrabri New South Wales and Kununurra in Western Australia differed in expressed traits from the commercial strain CC1192. These unique traits could provide additional tools for rhizobial strain selection to benefit chickpea production in different soil environments.

Influence of in situ ettringite formation on the rheological properties of quartz suspensions

Cement suspensions are subject to hydration processes causing dissolution of cement clinker, precipitation of hydration products and changes in the ion content of the carrier liquid. These mechanisms take place in parallel and control the workability of cement suspensions. The precipitation of nano-granular ettringite is currently believed to be one of the key influencing factors for rheological properties of fresh cement suspensions. In order to quantify the effect of ettringite precipitation from other precipitation or dissolution processes onto the rheological behaviour, a model suspension consisting of quartz powder and in situ formed ettringite is used, enabled by implementing a new upscalable synthesis route of ettringite. The quantity of formed ettringite in the model suspension is varied and derived qualitatively from X-ray diffraction as well as quantitatively from inductively coupled plasma optical emission spectrometry and thermogravimetric analysis. The influence of the ettringite content on the rheological properties is determined and linked to the specific surface of the formed ettringite particles. This allows a quantification of the controlling mechanism of ettringite and the dependency of these mechanisms on particle properties. The correlation of the results to a reference suspension without ettringite verifies the statement of influence.

Fate of bubble clusters rising in a quiescent liquid

We use experiments to study the evolution of bubble clusters in a swarm of freely rising, deformable bubbles. A new machine learning-aided algorithm allows us to identify and track bubbles in clusters and measure the cluster lifetimes. The results indicate that contamination in the carrier liquid can enhance the formation of bubble clusters and prolong the cluster lifetimes. The mean bubble rise velocities conditioned on the bubble cluster size are also explored, and we find a positive correlation between the cluster size and the rise speed of the bubbles in the cluster, with clustered bubbles rising up to $20\,\%$ faster than unclustered bubbles.

The origin of extraordinary selectivity in dehydrogenation of methylcyclohexane over Ni-Sn-based catalysts

High-loaded nickel catalysts (HLNCs) modified with Sn were synthesized and tested in dehydrogenation of methylcyclohexane (MCH) as a liquid organic hydrogen carrier. The catalyst composition and its reduction temperature were optimized that enabled to achieve the dehydrogenation selectivity of 99.0 % at a MCH conversion of 92 % and WHSV of 6.0 h−1, while the 99.9 % selectivity was reached at the conversion of 60.4 %, and WHSV of 18.5 h−1. Further, stability of the high selectivity of Sn-modified HLNCs was demonstrated in the long-run (100 h) catalyst test. The genesis of the HLNCs during their modification with Sn and reductive activation in hydrogen was studied. It was shown that the activation at temperatures above 450 °C resulted in a uniform distribution of Sn with the predominant formation of solid NiSn solutions having a crystal lattice of metallic nickel. The formation of the solid solutions provided a decrease in the adsorptive properties relating to the reaction product, toluene, which, in turn, led to an increase in the selectivity of MCH dehydrogenation.

Study of combination of liquid organic waste on antifungal activity Bacillus sp. DB12

This study examines the ability of liquid organic waste carriers to increase the antifungal activity of the active ingredient Bacillus sp DB12, which has been stored for 12 weeks against the pathogen Fusarium oxysporum f.sp. cepae. The research method was carried out in an experimental laboratory using a completely randomized design (CRD) with a single factor in the form of a liquid waste carrier consisting of 9 treatments. The composition of liquid tofu waste (TLW), coconut liquid waste (CLW), and rice washing liquid waste (RLW) was determined as follows: 100% TLW, 75% TLW + 25% CLW, 50% TLW + CLW 50%, TLW 25% + CLW 75%, CLW 100%, TLW 75% + RLW 25%, TLW 50% + RLW 50%, TLW 25% + 75% RLW, and 100% RLW. The results showed that the combination of 75% TLW + 25% CLW carriers increased the antifungal activity of Bacillus sp. DB12 compared to other carrier combinations. An increase in antifungal activity was indicated by an inhibition zone diameter of 13.03 mm during 12 weeks of storage.

In situ synthesis of C–SiO2 enhanced Pd nanoparticles for catalytic dehydrogenation of formic acid

Formic acid (FA, HCOOH), as a liquid chemical hydrogen storage carrier with low cost, high hydrogen content, and convenient storage and transportation, has attracted extensive attention. Pd-based catalysts for hydrogen production from FA are easy to aggregate and deactivate in the reaction process, which hinders the further development of FA as a hydrogen storage carrier. Therefore, the exploitation of carriers with simple preparation methods and excellent performance can effectively improve the catalytic activity of Pd-based catalysts. Porous carbon and SiO2 have been widely used for their unique structural properties, and the preparation of composite carriers by combining the advantages of both is a current research hotspot. Herein, this work synthesized C–SiO2 for the deposition of Pd nanoparticles by a one-step method, and the obtained Pd/C–SiO2 exhibits a superior FA dehydrogenation activity with a turnover frequency value of 1278 h−1 and a favorable stability with only a slight decrease in activity after five cycles.

Establishment and evaluation of a modified mouse model of renal subcapsular transplantation of microvolume cells

The renal subcapsular space provides an easily accessible, nutrition-rich pocket that supports engraftment, and as such, is often used as a site for stem and cancer cell transplantation. Renal capsule transplantation requires high technical requirements, the recipient mice have greater surgical damage, the mouse kidney is small and the kidney capsule is fragile, and the operation is easy to fail. The conventional method is not suitable for microvolume cell transplantation to this site in animals with a small kidney, such as mice, due to high risks of cell loss or dislocation or injury to the capsule. In this study, we developed and validated a modified approach for the mouse model of renal subcapsular transplantation of microvolume mouse skeletal stem cells (SSCs). We used a pipette with a refined tip to separate the capsule from the parenchyma. Moreover, we used cells suspended in Matrigel rather than a liquid carrier for transplantation. Using the modified method, we were able to transplant microvolume mouse SSCs as low as 0.2 μL beneath the mouse renal capsule with excellent reproducibility. After 4 weeks of in vivo culture, the implanted mouse SSCs formed grafts on the surface of the parenchyma at the target site of transplantation. Histological staining of the grafts indicated osteogenic, fibrogenic, and lipogenic differentiation. Micro-CT imaging of the grafts revealed bone formation. This modified model could be used to effectively transplant different types of microvolume cells to the renal subcapsular space when the donor cells are difficult to acquire or the recipient mice have a very small size kidney.

Carbon-Neutral Energy Cycle via Highly Selective Electrochemical Reactions Using Biomass Derivable Organic Liquid Energy Carriers

Abstract Efficient storage and transport of electric energy is essential to promote the use of renewable energy based electricity. We demonstrate an energy cycle based on highly selective redox reactions between lactic acid (Lac) and pyruvic acid (Pyr), both of which are liquid under ambient conditions and can be obtained from biomass resources, thus realizing a completely low-emission system. As an energy storage device, an electrosynthesis cell (LAEC) for the production of Lac from Pyr was constructed using a membrane electrode assembly (MEA) consisting of a TiO2 cathode catalyst for the electroreduction of Pyr and an IrOx anode catalyst for water oxidation. Our LAEC achieved highly efficient Lac production from 10 M Pyr aqueous solution with Faradaic efficiency (FE) of approximately 100% in the applied voltage range of 1.4–2.4 V, resulting in an energy conversion efficiency of 50% and a current density of −0.4 A cm−2 at 2.0 V. Direct Lac fuel cell (DLAFC) was also constructed and its FE values for the Pyr production reached approximately 100%, enabling direct electronic energy storage in bio-derivative liquid carriers and efficient energy circulation with minimal CO2 emissions.

A three-phase reactor assessment for the deployment of Liquid Organic Hydrogen Carriers (LOHCs): dybenzyltoluene and indoles mixture systems as case studies

As a result of the large increase in the production of renewable energies, energy storage and energy carrier systems are required to meet the most ambitious objectives. In this area, hydrogen stands out as one of the most powerful tools. However, its low volumetric energy density and its challenging storage conditions lead to the search for new forms of storage. Liquid organic hydrogen carriers (LOHCs) are positioned as a promising option to store hydrogen using a catalytic reversible reaction at moderate temperature. Notwithstanding, although reactor technology is the core section of the LOHC process, it has not been assessed yet. Therefore, in this work, a three-phase reactor analysis is performed including mass, heat, and momentum phenomena along with kinetics. In particular, the two most important reactors for three-phase reactions are evaluated, trickle bed and slurry. And two of the most attractive LOHCs systems, dybenzyltoluene and a mixture composed of 1,2-dimethylindole and 7-ethylindole, are considered. The influence of the operating and design variables was studied. The results show that, for hydrogenation slurry reactors, a first region may be formed where gas–liquid is the main resistance (60%–95%). It eventually ends up with a second one where kinetics becomes the controlling step. At this point, a better catalyst use is expected for the first region. Alternatively, trickle bed hydrogenation reactors are largely controlled by mass transfer over almost the whole reactor length. If the dehydrogenation process is assessed, kinetics resistance is predominant. Surrogate models are developed to optimize the reactor performance and to include the full reactor operation in futures process design analysis allowing for an effective deployment of LOHCs systems.

Appraising the impact of COVID-19 on trading volume of selected vessel types in sub-Saharan Africa

The emergence and diffusion of coronavirus (COVID-19) have brought a lot of impacts on various spheres of human endeavours including maritime trading. This paper explores the effect of the lockdown on maritime port calls for selected vessels in the sub-Saharan African (SSA) regions (East, Middle, South, and West Africa). The study utilizes port calls data of the maritime profile of the global economies obtained from the United Nations Conference on Trade and Development Statistics between 2018 and 2021. Data include port calls for liquid bulk carrier, liquefied petroleum gas, dry bulk carrier, dry break bulk carrier, roll-on-roll-off, and container carrier. The analysis of data involves the use of exploratory technique to reveal dimensions of performance by various carriers across the regions. The results picture the kind of response of port calls in all the regions akin to the response from other regions of the world. However, the study observes that though responses to COVID-19 lockdown across the globe were similar, SSA regions were slow in recovering from the decline in port calls when compared to the developed and some rapidly developing economies of the world due to the region’s lack of economic resilience. Thus, since ports have been identified as vulnerable to economic, social, institutional, and environmental shocks, and to dynamic and highly unpredictable demand for port services, policymakers of various nationals in the SSA may need to examine the patterns of performance of vessels in the regions to manage trade flows more effectively as a way of responding to future dynamics in maritime trade in the region.

Photocatalytic H2O2 production from water and air using porous organic polymers

Producing hydrogen peroxide (H2O2) from H2O and O2 under visible light irradiation is a promising solar-to-chemical energy conversion technology. Hydrogen peroxide has versatile applications as a green oxidant and liquid energy carrier but has been produced through energy-intensive and complex anthraquinone processes. Herein, we report the rational design of efficient and stable porous organic polymer (POP) containing redox centers, anthraquinone photocatalyst (ANQ-POP) for solar H2O2 production. ANQ-POP is readily synthesized with stable dioxin-linkages via efficient one-pot, transition-metal-free nucleophilic aromatic substitution reactions between 1,2,3,4,5,6,7,8-octafluoro-9,10-anthraquinone (OFANQ) and 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP). Exhibiting a fibrillar morphology, ANQ-POP boasts a high surface area of 380 m2∙g−1 and demonstrates thermal stability. With 10 % ethanol, ANQ-POP yields an H2O2 production rate of 320 μmol g−1 under visible light irradiation. Moreover, ANQ-POP alone can efficiently produce H2O2 without any photosensitizers and cocatalysts. Density functional theory calculations reveal that the quinone groups of the anthraquinone moieties can serve as redox centers for H2O2 production under light irradiation. Furthermore, unlike most conventional photocatalysts, it can produce H2O2 using only water and air by catalyzing both oxygen reduction and evolution reactions under light irradiation. Our findings provide an efficient, eco-friendly pathway for photocatalytic production of H2O2 under mild reaction conditions using a dioxin-derived POP-based photocatalyst.

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This research article presents a study on the potential use of oil-based ferrofluid for the efficient removal of microplastics from water. The targeted analyte, micro-polystyrene (micro-PS), was chosen along with palm oil as the carrier liquid. Fourier Transform Infrared (FTIR) analysis was conducted to identify the main peaks in the ferrofluid, including carboxyl group (1542 cm-1), C-H bonding (1022 cm-1), CH2 bonding (2941 cm-1), CH3 bonding (3461 cm-1), C=C bonding (1255 cm-1), and Fe-O (597.34 cm-1). A comprehensive investigation of the synergistic effect of six variables was performed: volume of oil (4-15 mL), weight of magnetite nanoparticles (0.1-0.2 g), stirring rate (132-468 rpm), contact time (3-12 min), pH value of water samples (pH 6-8), and effect on ionic strength (0-16 g/L). Response surface methodology, including 26-Plackett-Burman and 24-central composite design, were employed to establish the relationship between the variables. The optimum operational settings proposed by the model were as follows: volume of oil (14.6 mL), weight of magnetite nanoparticles (0.1 g), stirring rate (216 rpm), contact time (3.29 min), pH value of water samples (pH 6-6.5), and effect on ionic strength (16 g/L), resulting in a remarkable removal efficiency of 91.09 ± 0.99%. The method exhibited desirable figures of merit, including a low bias (%RSD) of below 5% and the ability to reuse the ferrofluids for up to five cycles. Additionally, an analytical greenness metric was employed to assess the environmental impact of the sample preparation process, with a green score of 0.69/1.0 (indicating a light green colour). Future work in this field could focus on the scalability of the developed method and its applicability to real-wastewater treatment.

Thermal design and heat transfer optimisation of a liquid organic hydrogen carrier batch reactor for hydrogen storage

Liquid organic hydrogen carriers (LOHCs) are considered a promising hydrogen storage technology. Heat must be exchanged with an external medium, such as a heat transfer fluid, for the required chemical reactions to occur. Batch reactors are simple but useful solutions for small-scale storage applications, which can be modelled with a lumped-parameter approach, adequately reproducing their dynamic performance. For such reactors, power is consumed to circulate the external heat transfer fluid and stir the organic liquid inside the reactor, and heat transfer performance and power consumption are two key parameters in reactor optimisation. Therefore, with reference to the hydrogen release phase, this paper describes a procedure to optimise the reactor thermal design, based on a lumped-parameter model, in terms of heat transfer performance and minimum power consumption. Two batch reactors are analysed: a conventional jacketed reactor with agitation nozzles and a half-pipe coil reactor. Heat transfer performance is evaluated by introducing a newly defined dimensionless parameter, the Heat Transfer Ratio (HTR), whose value directly correlates to the heat rate required by the carrier's dehydrogenation reaction. The resulting model is a valid tool for adequately reproducing the hydrogen storage behaviour within dynamic models of complex and detailed energy systems.

Intensified swirling reactor for the dehydrogenation of LOHC

In the recent advances towards more sustainable global energy supply, H2 is a possible alternative for large scale energy storage. In this view, Liquid Organic Hydrogen Carriers (LOHC) are a class of molecules that allow for easier long term energy storage compared to conventional H2 technologies. CFD simulations were used to showcase the hydrodynamics of the dehydrogenation of a LOHC in a new reactor unit, via a cold flow mock-up study. This reactor was designed to allow for a swirling motion of the liquid carrier material, favouring the removal of H2 gas from the flow and forcing the equilibrium of the reaction towards dehydrogenation, as well as to keep the catalyst particles in motion. The CFD simulations were validated qualitatively with experimental operation of the reactor, in a system with identical dimensionless numbers (Reynolds and Stokes), in order to use less costly products during the prototyping phase.

Spitting for Science: Non-Invasive Drug Monitoring Through a Modified Liquid Micro Junction-Surface Sampling Probe

The use of saliva as a convenient, non-invasive alternative for therapeutic drug monitoring has become increasingly favorable with the emergence of pharmacokinetic and bioequivalence research providing a link between blood plasma and saliva concentrations. Therapeutic drug monitoring is a practice through which specific drugs are monitored at given time intervals to maintain a constant concentration in the blood. It is only necessary for patients taking drugs with known pharmacokinetic variability, narrow therapeutic indices and potential adverse effects.
 Although the drug concentration in saliva is lower than in plasma, saliva has a complex matrix, consisting of salts, immunoglobins, proteins and more. The polar matrix in the saliva introduces potential interference with the sensitivity of the drug detection through salt suppression.
 In this project, 6 drugs used as anticonvulsants and antidepressants were analysed in artificial saliva using a modified version of the Liquid Micro Junction-Surface Sampling Probe (LMJ-SSP) to maximize the sensitivity of observed signals and minimize the detection limits.
 The main parameter which was targeted for optimizing the extraction and ionization of the drug in the saliva samples was the polarity of the carrier liquid, which continuously flows in the coaxial tube of the LMJ-SSP. Upon analyzing four different carrier liquids, the mixture containing methanol, water and chloroform was determined to provide the best sensitivity. Additionally, the enrichment factors of the peak areas using the chloroform mixture in the modified LMJ-SSP were enhanced by a factor ranging between 2.9 to 31.4, depending on the analyte.
 Overall, the data obtained from this project thus far displays that modifying the polarity by modifying the carrier liquid composition to balance the extraction and ionization during analysis using the modified LMJ-SSP optimizes the sensitivity of the detection.