Oil Suspension Research Articles

CHARACTERISTIC OF COMPLEX COMPOUNDS OF CUPRUM (II) NITRATE WITH ALIPHATIC AMINES PYRIDINE AND ITS DERIVATIVES IN CRYSTAL STATE

Complex compounds of CuCl 2 і Cu(NO 3 ) 2 with aliphatic amines in a crystalline state from alcohol solutions were obtained. The composition of the obtained compounds was determined by the method of equilibrium shift, molar ratios and intersection of the curves. Their electronic and IR spectra were studied, and a wide asymmetric absorption band was detected in the near region with a maximum of 870 - 900 nm. This band is characteristic of compounds of a tetrigonally curved octahedral configuration. The formation of complex compounds Cuprum (II) with amines of 1:1, 1:2 composition was established. Measured vibrational spectra in the region of 500 to 200 см -1 . IR-spectra of samples of complex compounds Cuprum (II) with the aliphatic amines, pyridine and its derivatives was measured as a suspension in vaseline oil. The measurements were carried out on an IKS-228 spectrophotometer. The frequency of stretching vibrations Me-N characterizes the coordination bond. The stretching vibrations of Me-N should manifest themselves in the low-frequency region as a result of a significant mass of the metal atom and the relatively low strength of the coordination bond. The IR spectra indicate Me-N stretching vibrations, which characterize the coordination bond. For aliphatic amines, absorption bands were identified in the region of 440–420 см -1 , which are assigned to V(Cu–N) vibrations. The bands in this region indicate coordination through the base nitrogen atom. The absorption bands of the ligands in the region of 210-220 см -1 disappear in the complex compounds. Most of the frequencies in complex compounds are explained by the dual nature of the σ- and π- dative interactions. In coordination compounds of Cu(NO 3 ) 2 with pyridine and its derivatives, an increase in vibration frequencies is observed with an increase in the stability of complex compounds, which is explained by the double nature of the bond (σ,-and π-dative interaction). Complex compounds were studied by differential thermal analysis. As a result, it was concluded that the nature of the decay of the complexes is affected by the nature of the ligand, complexing agent, electronegativity and polarizing properties of the ligand, steric effects and the nature of cations. The process of breaking the coordination bond for primary and secondary aliphatic amines occurs stepwise, and for tertiary amines in one step. At the first stage, one ligand molecule is cleaved, and at the second, the second molecule. Secondary amines have small cleavage. With an increase in the spatial factors of amines, the thermal stability of the complexes decreases.

Capillary breakup extensional electrorheometry (CaBEER)

A new electrorheological cell for the capillary breakup extensional rheometer (HaakeTM CaBER 1TM, Thermo Scientific) allowing the analysis of the rheological properties of complex fluids under the simultaneous application of an extensional flow and an electric field has been developed and tested. In this study, the add-on is described in full detail and different cornstarch suspensions in olive oil are characterized under different stretching conditions with and without an electric field. The results show that, under extensional flow and no electric field, the sample behaves as a Newtonian-like fluid, showing a linear relationship between time and filament minimum diameter. However, when the external electric field is imposed, the filament thinning process delays increasing the breakup time. If the external electric field is further increased, then the filament may even not break, depending on the imposed voltage, the Hencky strain, and the concentration of particles in the fluid sample.

Randomized controlled trial of a water-soluble formulation of lutein in humans

Lutein is poorly absorbed owing to their high hydrophobicity and crystallinity. This double-blind crossover trial involved eight healthy males who were administrated capsules containing either a lutein water-soluble formulation or a lutein oil suspension for 8days. In the formulation group, plasma and erythrocytes lutein concentrations and baseline-corrected AUC were two-fold higher than those in the oil suspension group.

Study of self-preservation of gas hydrates in suspensions in oils

Impact of different parameters on the decomposition rates of hydrate at negative temperatures with depressurisation method has been studied. In previous work it was demonstrated that decomposition rates of hydrates suspensions in oil at static conditions can be limited by the self-preservation phenomenon. Our experimental research shows that appearance of self-preservation depends on many parameters such as components composition of oil, presence of shear in the system while decomposing hydrates and probably on the history of the sample.

Microexplosive Atomization of Heterogeneous Fuel Drops for Intensifying Their Ignition

Models of microexplosive atomization of two-liquid unmixed drops under high-temperature heating are developed. Two most common mechanisms, namely, superheating of interphase boundary and critical bubble size, are chosen as atomization criteria. Two mathematical models, one based on solution of heat conduction equation and the other on VOF, are presented. The studied drops contain rapeseed oil and aqueous suspension of graphite. Experiments were conducted to determine the time lag of atomization of moving two-liquid unmixed drops under high-temperature heating. The theoretical and experimental atomization time lag values are found to be in satisfactory agreement. The results can be used to develop existing and create new gas-vapor-droplet technologies in chemical and petroleum engineering fields because they help predict the conditions of intense secondary atomization of heterogeneous drops by microexplosive dispersion.

Preparation of an oil suspension containing ondansetron hydrochloride as a sustained release parenteral formulation.

Ondansetron hydrochloride (ODS) is a selective 5-hydroxytryptamine type 3 antagonist for nausea and emesis prevention in neoplastic patients. To reduce dosing frequency and side effects and improve patient compliance, a sustained release parenteral formulation of ODS was developed. Microparticles of methylcellulose (MC) and ODS were prepared using the spray-drying method and suspended in oils to form oil suspensions. The formulations were evaluated for residual moisture, drug content, size distribution, DSC, XRD, FTIR, SEM, drug release, and pharmacokinetic studies. The effects of polymers and oils on the drug release were evaluated. MC showed the most prominent sustained release effect among various polymers examined with the optimum MC/ODS ratio of 2:1 (w/w). The particle size of the produced microparticles was in the mean diameter of approximately 3 μm. Physicochemical characterization suggested that ODS existed in an amorphous matrix within the microparticles and interacted with MC via hydrogen bonds. Corn oil was selected as the appropriate oil for suspension due to the sustained release of ODS and the appropriate viscosity. The optimized sustained release formulation of ODS was the corn oil suspension of spray-dried microparticles containing MC and ODS (2:1, w/w). It showed an in vitro drug sustained release up to 120 h, while the oil suspension of ODS without any polymer released the drug within 2 h. Following subcutaneous administration in rats, the optimized formulation could prolong the drug release until 72 h with the enhanced bioavailability in comparison with the ODS solution. The oil suspension of spray-dried microparticles might be an efficient approach for prolongation of the drug effect in the management of nausea and emesis. Graphical abstract.

The Influence of the Myricetin on the Liver, Kidney, Spleen and Some Endocrine Glands of Male Rats at Prepubertal Period

In this study, the effects of myricetin exposure to rats from postnatal day (PND) 23 to 53 at various doses were investigated. The male rats were divided into five groups and each group consisted of six animals. Group of rats were treated with myricetin 25 and 50 mg/kg/day in a suspension of corn oil. Positive control males were received gavage orally with 17α-ethinyl estradiol 0.7 and 7 µg /kg /body weight day and control males were received corn oil. End of the study, weights of liver, kidney, spleen, pancreas, thymus and adrenal gland were measured. Organ/body weight ratios were calculated and tissue sections were examined histologically. In liver, the TUNEL method was applied and evaluated. In results, absolute liver weights were decreased statistically in 0.7 and 7 µg/kg/day etinil estradiol and 50 mg/kg/day myricetin treatment groups, compared with the oil control group. Histopathological examination of the liver, kidney and spleen revealed significantly increased frequency of congestion, cell degeneration and mononuclear cell infiltration when compared with the control group. Also myricetin dose groups, the apoptotic cells were increased. This study demonstrated that orally gavages myricetin caused adverse effects on male liver, kidney, spleen and endocrine glands, during peripubertal period to pubertal period.

First MnO2-based electrorheological fluids: high response at low filler concentration

Nanoparticles of MnO2 with different shapes (needle-like α-MnO2 and spherical δ-MnO2) were proposed as promising fillers for electrorheological fluids (ERFs). A thorough study of the dielectric properties of α-MnO2 and δ-MnO2 suspensions in silicone oil enabled estimation of the values of their dielectric permittivity and dielectric relaxation times. The study of MnO2-filled materials with various filler contents, and under various electric field strengths, in shear and uniaxial tensile and compressive stress regimes, revealed that needle-like α-MnO2 nanoparticles, in comparison with spherical δ-MnO2 particles, lead to better mechanical properties of the fluids. The most intriguing property of MnO2-based electrorheological fluids is their high electrorheological response at low filler content: ERF containing only 4.5 vol.% of α-MnO2 in silicone oil demonstrated a 18 kPa tensile strength in a 5 kV electric field.

Encapsulation of Micro- and Milli-Sized Particles with a Hollow-Type Spherical Bacterial Cellulose Gel via Particle-Preloaded Droplet Cultivation.

A hollow-type spherical bacterial cellulose (HSBC) gel prepared using conventional methods cannot load particles larger than the pore size of the cellulose nanofiber network of bacterial cellulose (BC) gelatinous membranes. In this study, we prepared a HSBC gel encapsulating target substances larger than the pore size of the BC gelatinous membranes using two encapsulating methods. The first method involved producing the BC gelatinous membrane on the surface of the core that was a spherical alginate gel with a diameter of 2 to 3 mm containing the target substances. With this method, the BC gelatinous membrane was biosynthesized using Gluconacetobacter xylinus at the interface between the cell suspension attached onto the alginate gel and the silicone oil. The second method involved producing the BC gel membrane on the interface between the silicone oil and cell suspension, as well as the spherical alginate gel with a diameter of about 1 mm containing target substances. After the BC gelatinous membrane was biosynthesized, an alginate gel was dissolved in a phosphate buffer to prepare an HSBC gel with the target substances. These encapsulated substances could neither pass through the BC gelatinous membrane of the HSBC gel nor leak from the interior space of the HSBC gel. These results suggest that the HSBC gel had a molecular sieving function. The HSBC gel walls prepared using these methods were observed to be uniform and would be useful for encapsulating bioactive molecules, such as immobilized enzymes in HSBC gel, which is expected to be used as a drug carrier.

In Ukrainian

The effect of the surface modification of fumed silica (SiO 2 ) with poly(dimethylsiloxane) (PDMS) on the rheological properties of its suspensions in vaseline oil has been studied in the current work. The composites with different polymer content (from 5 to 40 wt. %) were synthesized by using the method of liquid phase adsorption modification of silica with linear PDMS-1000 (molecular weight W m ≈ 7960, degree of polymerization d p = 105). It is shown that the structural and morphological characteristics of SiO 2 /PDMS composites are significantly different from those for the initial silica, and depend on the concentration of PDMS. In particular, the specific surface area of the composites, determined by the method of low-temperature desorption of argon, is inversely correlated with the content of polymer. The morphology of SiO 2 /PDMS composites and aggregation of primary particles of fumed silica strongly depends on the method of liquid phase adsorption modification: the initial fumed SiO 2 has a wider distribution of aggregates in size than that in polymer composites according to AFM data. Suspensions with a solid phase concentration (SiO 2 /PDMS) of 5 wt. % in a lyophilic dispersion medium (vaseline oil) demonstrate typical thixotropic behavior with a characteristic hysteresis loop on the rheogram, corresponding to increasing the destruction of the dispersion structure while stepwise shear rate increment and partial its restoration while subsequent stepwise shear rate decrement. Both the effective viscosity values corresponding to the maximum destruction of the suspension structure obtained at high shear rates and the effective viscosity values corresponding to partial restoration of the structure in the subsequent stepwise shear rate decrement mode decrease with increasing polymer content in the studied composites. However, it has been found that the initial values of the effective viscosity for the studied dispersions with a practically almost intact structure (at the lowest shear rates) are higher for dispersions of SiO 2 /PDMS composites with a low concentration of PDMS 10–20 wt. % compared with similar suspensions of the initial silica. A correlation between the effective viscosity and the specific surface area of composites is shown.

Surfactant-Switched Positive/Negative Electrorheological Effect in Tungsten Oxide Suspensions.

The electrorheological (ER) effect was experimentally observed in dielectric suspensions containing tungsten oxide (WO3) modified with surfactant molecules (sodium dodecyl sulfate (SDS) and dodecylamine (DDA)) in electric fields up to several kilovolts per millimeter. The dielectric properties of WO3 suspensions in silicone oil were analyzed, depending on the frequency of the electric field, in the range from 25 to 106 Hz. Unmodified WO3 suspensions, as well as suspensions modified with sodium dodecyl sulfate, were shown to exhibit a positive electrorheological effect, whereas suspensions modified with dodecylamine demonstrated a negative electrorheological effect. The quantitative characteristics of the negative electrorheological effect in the strain–compression and shear regimes were obtained for the first time. Visualization experiments were performed to see the chain structures formed by WO3 particles modified with sodium dodecyl sulfate, as well as for dynamic electroconvection in electrorheological fluids containing WO3 modified with dodecylamine. The negative electrorheological effect was shown to be associated with the processes of phase separation in the electric field, which led to a multiplicative effect and a strong electroconvection of the suspension at field strengths above 1 kV/mm.

Tribological Properties of New Developed Nano Boric Acid Suspended as Additive in Engine Oil

It is well known that nanoparticles affect the interaction between lubricants and surfaces with various chemical compositions and different chemical and physical properties. In recent years, nanoparticles have started to play more important roles as lubricant additives for their potential in wear, friction and emission reduction and improving lubrication and fuel economy. Although nanolubricants are frequently used for friction tests, little is known about stability and degree of dispersion of these nanoparticles in viscous liquids. Most of them are unstable, agglomerate or aggregate which sediment over time. Boric acid (H3BO3) has always been a very important material due to its broad range of applications such as in medicine, cosmetics, automotive industry, metallurgy and also for miscellaneous purposes in other areas. Literature survey showed that friction between automobile engine parts could be greatly reduced using microscopic particles of boric acid.This study involves the new invention of successful suspension of nano boric acid (BA) additive added into 5W-40 fully synthetic commercial lubricating oil. This invention is confidential and realized by Murat ÖZAYMAN from Tribor ARGE Co. in Teknopark of YILDIZ Technical University in Istanbul-TURKEY. The particle size of BA is determined with (Transmission Electron Microscopy) (TEM). Backscattering and transmittance profiles proved that nano boric acid (BA) particles were in suspension in commercial engine oil. Suspended BA in engine oil is applied between piston ring and cylinder liner system in order to investigate their effect on friction and wear under boundary lubricated conditions. Simulation and measurement of friction and wear were conducted using a reciprocating tribometer. Surface analysis were performed using 3D digital optical microscope, Field Emission Scanning Electron Microscope (FESEM)/X-Ray, X-ray photoelectron spectroscopy (XPS) and Atomic Force Microscopy (AFM). Boron (B) from BA is well detected, mixed with other elements of additives and protected the surface under boundary lubrication conditions. The results indicate that BA can considerably improve the tribological performance of a piston ring and cylinder liner system under lubricated conditions. It has found that the friction coefficient is reduced with nano boric acid (BA) suspended engine oil and protected the surface mostly on cylinder liner mixing with other additives.

Application of Suspended Nanoboric Acid as an Efficient Lubrication Additive in Engine Oil

Lubricants play a vital role in machine life and performance, reducing friction and wear and preventing component failure. Performance-enhancing additives are a vital part of today’s modern lubricants. In response to this need, this experimental work presents the development of the new suspended nanoboric acid (nBA) additive added in engine oil that can drastically lowered friction and wear.This is a new invention of nBA additive hold in suspension and added into 5W-40 fully synthetic commercial lubricating oil. This invention is confidential and realized by Tribor ARGE Co. in Teknopark of YILDIZ Technical University in Istanbul-TURKEY.The particle size of nBA is determined with (Transmission Electron Microscopy) (TEM). Turbiscan Tower Stability Analyzer results proved that nBA particles were in suspension in commercial engine oil. Suspended nBA in engine oil is applied between ball and disk system in order to investigate their effect on friction and wear under lubricated conditions. Simulation and measurement of friction and wear were conducted using a ball on disk reciprocating tribometer UMT-3. Surface analysis was performed using 3D digital optical microscope and surface roughness, Field Emission Scanning Electron Microscope (FESEM)/X-Ray and Atomic Force Microscopy (AFM). Boron (B) from nBA is well detected, mixed with other elements of additives and protected the surface under boundary lubrication conditions. The results indicate that nBA can considerably improve the tribological performance of a ball and disk pairs under lubricated conditions. It has found that the friction coefficient is reduced with nBA suspended engine oil and protected the surface on both ball and disk mixing with other additives.

PH dependence of the chirality of nematic cellulose nanocrystals

Cellulose nanocrystals produced by acid hydrolysis of native cellulose form a well-known chiral nematic liquid crystal phase. The mechanism involved in the formation of chirality has been the subject of a vigorous discussion. The pH and concentration dependence of the phase is studied using cellulose nanocrystal droplets within a silicon oil suspension, which allows for convenient real-time microscale manipulation of phase behaviors and properties. We demonstrate the existence of nematic phases at both low and high pH regions consistent with the Stroobants - Lekkerkerker - Odijk theory. Our results confirm electrostatic interactions play a critical role in controlling the strength of the chirality.

Printing of Hydrophobic Materials in Fumed Silica Nanoparticle Suspension.

Freeform three-dimensional (3D) printing of functional structures from liquid hydrophobic build materials is of great significance and widely used in various fields such as soft robotics and microfluidics. In particular, a yield-stress support bath-enabled 3D-printing methodology has been emerging to fabricate complex 3D structures. Unfortunately, the reported support bath materials are either hydrophobic or not versatile enough for the printing of a wide range of hydrophobic materials. The objective of this study is to propose a fumed silica nanoparticle-based yield-stress suspension as a hydrophobic support bath to enable 3D extrusion printing of various hydrophobic ink materials in a printing-then-solidification fashion. Hydrophobic ink is freeform-deposited in a hydrophobic fumed silica-mineral oil suspension and maintains its shape during printing; it is not cured until the whole structure is complete. Various hydrophobic inks including poly(dimethylsiloxane) (PDMS), SU-8 resin, and epoxy-based conductive ink are printed into complex 3D structures in the fumed silica-mineral oil bath and then cured using relevant cross-linking mechanisms, even at a temperature as high as 90 °C, to prove the feasibility and versatility of the proposed printing approach. In addition, the deposited feature can easily reach a much better resolution such as 30 μm for PDMS filaments due to the negligible interfacial tension effect.

Effects of asphaltene concentration and asphaltene agglomeration on viscosity

Asphalenes are regarded as the most polar and heaviest components in crude oil system. Their precipitation and agglomeration cause problems in oil recovery, production, and transportation. Asphaltenes are directly responsible for determining the viscosity of crude oil. In this work, the effects of asphaltene concentration and asphaltene agglomeration on viscosity were investigated. Toluene and heptane were used as asphaltene solvent and precipitant. The viscosities of asphaltenes-toluene solutions with various asphaltene concentrations were measured to investigate the impact of asphaltene concentration on viscosity. The results indicate that the viscosity of asphaltene-toluene solution exponentially increases with the asphaltene concentration. Elevated temperature causes viscosity reduction. The effect of temperature on viscosity reduction is more significant at higher asphaltene concentration. The dependence of viscosity on temperature can be well described by the Arrhenius equation, by considering the significance of activation energy. On the other hand, the asphaltene agglomerates form and grow with the increase of heptane concentration in crude oil-heptane-toluene mixture. A sharp viscosity rise of crude oil-heptane-toluene mixture was observed beyond heptane threshold concentration of 60 vol%. This is mainly resulted from the significant formation and growth of asphaltene agglomerates in asphaltene suspensions. The interactions between micro-sized asphaltene agglomerate particles could significantly affect the viscosity of liquid–solid system. The particle properties of asphaltene agglomerates including size, size distribution, number and shape factor were analyzed by microscopic images of the synthetic diluted oil. These contribute to the understanding of the effect of particle properties of asphaltene agglomerates on the viscosity of oil suspension.

Modeling and Simulation of Modular Independent Oil and Gas Suspension Mechanics

The modular independent oil and gas suspension had become the key to achieving high maneuvering off-road capability for a new generation of military special vehicles, aiming at this situation, the modeling of characteristics of modular independent suspension and oil gas spring were researched. It was proposed to use the actual gas state equation to derive the nonlinear elastic properties, and taked the double wishbone independent suspension as the main research object to complete the analytical calculation of the kinematics and dynamics of the guiding mechanism, after that the force state of each hard point coordinate was clarified. The simulation analysis of the suspension characteristics and key parameters with displacement was carried out by programming, and the mechanical influence law of the independent oil and gas suspension system was revealed, which laid a foundation for engineering design.

Painting method for hydroxyapatite coating on titanium substrate

Abstract Coating on prostheses and implantable devices is one of the ways to increase the osseointegration of these products. However, plasma spray techniques, that are normally used, present high complexity and high cost. In this work, a new methodology for coating with nanometric hydroxyapatite is presented, with a low cost and ease of production. The technique proposed involves the formation of a suspension of hydroxyapatite (HAp) and oil of turpentine (OT) and its application, with a paintbrush, on the titanium substrate. In order to qualify the process for medical devices, the properties of the titanium substrate, before and after the coating process, the calcium phosphate phases present and the adhesive bond of the coating were evaluated. The results indicated that thermal treatment does not affect the properties of ASTM F67 titanium in order to compromise the properties and the analyses, by X-ray diffraction and Raman spectroscopy, proved that no formation of second phases of calcium phosphate occurred. The adhesive bond assay showed that the coating behaved according to ISO 13779–2, i.e., it had adhesive bond values higher than 15 MPa. The proposed new coating method proved promising for the titanium coating and is an alternative to the complex and high cost processes normally used in metal implants.

The protective effects of diallyl sulfide (DAS) on benzene-induced leukopenia in mice

Objective: To study the protective effects of diallyl sulfide (DAS) on leukopenia induced by benzene. Methods: 90 Healthy male ICR mice, adaptive feeding 5 days later, 15 were randomly divided into blank control group、model group、low、middle、high dose DAS intervention groups and DAS control group. Mice in intervention groups and DAS control group were orally given DAS at 40, 80, 160, 160 mg/kg·bw, while mice in the other two groups received an equal volume of corn oil. After 2 hours, model group and the other three intervention groups were given benzene, corn oil suspension (1.3 g/kg·bw) , the two control groups treated with the same volume of corn oil, Benzene and DAS are dissolved in corn oil. one time for each day. 4 weeks later, Anesthesia at 14/29, make blood routine examination and count organ index and observe pathological examinations of spleen and thymus. Results: On day 14, the counts of peripheral blood white blood cells (WBC) , lymphocytes, monocytes in the model group decreased to 68.99%, 71.72%, 53.19% (P<0.05) ; On day 29, the counts of peripheral blood lymphocytes, monocytes, neutrophils in the model group decreased to 83.00%, 81.03%, 89.37%, 20.84%, 19.25% (P<0.05) ; spleen weight, spleen index, white pulp area ratio of spleen, thymus weight, thymus index, thymic cortex area ratio of mice in the model group decreased (P<0.05) . On day 14, the counts of peripheral blood monocytes and lymphocytes in the DAS high dose intervention group increased by 136.36%, 260.00% (P<0.05) ; On day 29, the counts of White blood cells, lymphocytes, red blood cells, platelets, hemoglobin in the DAS low, middle and high dose intervention groups increased (P<0.05) ; spleen weight, spleen index, white pulp area ratio of spleen, thymus weight, thymus index, thymic cortex area ratio of mice in the DAS high dose intervention groups increased (P<0.05) . Conclusion: DAS can effectively suppress benzene-induced leucopenia in mice.

Development of an oil suspension containing granisetron hydrochloride as a sustained-release parenteral formulation for enhancement of pharmacokinetic properties

A sustained-release parenteral formulation of granisetron hydrochloride, a water-soluble drug, was developed in the form of an oil suspension loaded with microparticles. Spray drying technique was employed to prepare microparticles of polymers and the drug without using organic solvents. The effects of polymers and oils on the drug release were evaluated. Methylcellulose was found to be the most effective among various polymers examined for the drug sustained-release. Physicochemical characterization suggested that methylcellulose and granisetron hydrochloride interacted within the microparticles via hydrogen bonds and that the drug was transformed to an amorphous state. The optimum sustained-release parenteral formulation was the suspension of the spray-dried microparticles of methylcellulose and granisetron hydrochloride (ratio 5:1) in the mixture of medium-chain triglycerides and castor oil (40:60, V/V). In vitro release study showed the sustained-release characteristics of the optimized formulation up to 72 h. The results of pharmacokinetic studies in rats showed the sustained-release characteristic of the optimized formulation with an extended Tmax and the enhanced systemic exposure compared to the drug solution. Encapsulation of hydrophilic drugs with methylcellulose into microparticles combined with the preparation of oil suspensions is a promising approach for the development of sustained-release parenteral formulations.