Ethanol Slurry Research Articles

Robocasting and surface functionalization with highly bioactive glass of ZrO2 scaffolds for load bearing applications

AbstractThis work is a proof of concept for making load bearing implants with osseointegration and bone bonding ability. Yttria‐stabilized zirconia (YSZ) scaffolds with a percentage of macro porosity of about 70% were fabricated by robocasting. Although a maximum solids volume fraction of 50 vol.% could be achieved, the 3D‐printing process revealed to be more reliable when using inks with 48 vol.% solids. The sintered porous structures exhibited an average compressive strength of ~236 MPa. After some preliminary coating experiments, an ethanol slurry of fine bioactive glass (BG) particles (10 wt.%) stabilized with polyvinylpyrrolidone was used to deposit a uniform surface coating onto the filaments, followed by glazing at 850°C. The functionalized scaffolds showed a relatively uniform surface coverage by the bioactive glass. The results of in vitro testing by immersing the scaffolds in simulated body fluid (SBF) showed remarkable morphological surface changes and an extensive deposition of hydroxyapatite layer. The overall results demonstrate the viability of producing porous YSZ scaffolds with excellent bioactivity, which are promising for bone tissue engineering under load bearing applications.

Nanostructured Iron Sulfide/N, S Dual-Doped Carbon Nanotube-Graphene Composites as Efficient Electrocatalysts for Oxygen Reduction Reaction.

Nanostructured FeS dispersed onto N, S dual-doped carbon nanotube–graphene composite support (FeS/N,S:CNT–GR) was prepared by a simple synthetic method. Annealing an ethanol slurry of Fe precursor, thiourea, carbon nanotube, and graphene oxide at 973 K under N2 atmosphere and subsequent acid treatment produced FeS nanoparticles distributed onto the N, S-doped carbon nanotube–graphene support. The synthesized FeS/N,S:CNT–GR catalyst exhibited significantly enhanced electrochemical performance in the oxygen reduction reaction (ORR) compared with bare FeS, FeS/N,S:GR, and FeS/N,S:CNT with a small half-wave potential (0.827 V) in an alkaline electrolyte. The improved ORR performance, comparable to that of commercial Pt/C, could be attributed to synergy between the small FeS nanoparticles with a high activity and the N, S-doped carbon nanotube–graphene composite support providing high electrical conductivity, large surface area, and additional active sites.

A Study on the Sintering of a Mixed Powder Containing Alumina and Aluminum for Control of Volume Shrinkage during Sintering

We studied the sintering of mixed powders in which either alumina or aluminum was coated with polysiloxane derived from aqueous slurry in order to avoid using organic solvent and to confirm the change of sintering process by coating only one of the powders. We found that similar characteristics of porous alumina can be obtained by sintering the mixed powder derived from an aqueous slurry and the mixed powder derived from an ethanol slurry. Coating the alumina powder with polysiloxane prevented the volume expansion of samples during sintering, thus increasing the density of the porous alumina and wettability between alumina and aluminum.

Coupled Si and O isotope measurements of meteoritic material by laser fluorination isotope ratio mass spectrometry.

We present a procedure for the determination of the isotopic ratios of silicon and oxygen from the same aliquot of anhydrous silicate material. The sample is placed in a bromine pentafluoride atmosphere as it is heated with a CO2 laser system releasing silicon tetrafluoride and oxygen gasses. The oxygen gas is then purified to remove other reaction by-products through several liquid nitrogen traps before being captured onto a molecular sieve and transferred to an isotope ratio mass spectrometer. The silicon tetrafluoride gas is then purified using a supplementary line by repeatedly freezing to -196°C with liquid nitrogen and then thawing with an ethanol slurry at -110°C through a series of metal and Pyrex traps. The purified gas is then condensed into a Pyrex sample tube before it is transferred to an isotope ratio mass spectrometer for silicon isotope ratio measurements. This system has silicon yields of greater than 90% for pure quartz, olivine, and garnet standards and has a reproducibility of ±0.1‰ (2σ) for pure quartz for both oxygen and silicon isotope measurements. Meteoritic samples were also successfully analyzed to demonstrate this system's ability to measure the isotopic ratio composition of bulk powders with precision. This unique technique allows for the fluorination of planetary material without the need for wet chemistry. Though designed to analyze small aliquots of meteoritic material (1.5 to 3 mg), this approach can also be used to investigate refractory terrestrial samples where traditional fluorination is not suitable.

Facile synthesis of nanostructured molybdenum carbide/nitrogen-doped CNT-RGO composite via a modified urea glass route for efficient hydrogen evolution

Homogeneously dispersed Mo2C nanoparticles onto nitrogen-doped carbon nanotube - reduced graphene oxide support (Mo2C/CNT-RGO) were prepared by a modified urea glass route. Simply heating an ethanol slurry of MoCl5, urea, CNT, and graphene oxide at 750 °C under nitrogen atmosphere uniformly distributed 8 nm Mo2C nanoparticles in the nitrogen-doped CNT-RGO support. The resultant Mo2C/CNT-RGO exhibited markedly improved electrochemical performance for hydrogen evolution reaction (HER) compared to similarly prepared Mo2C/CNT, Mo2C/RGO, and bare Mo2C. Enhanced Mo2C/CNT-RGO performance could originate from the synergy between Mo2C nanoparticles with high HER activity and N-doped CNT-RGO support providing large surface area and high electrical conductivity.

Dispersion of graphene in chlorosulfonated polyethylene by slurry compounding

It remains a huge challenge to realize the homogeneous graphene dispersion in elastomer matrix by a simple and general compounding method. Herein, we develop a straightforward slurry compounding method for preparation of rubber/graphene composites with well-dispersed graphene. Specifically, TPG (tea polyphenol reduced graphene)/ethanol slurry was first collected by solvent exchange after the reduction of graphene oxide by tea polyphenol and then directly melt compounded with chlorosulfonated polyethylene (CSM) in a two-roll mill to produce the composites. As revealed by the XRD and morphological studies, TPG homogeneously dispersed in CSM matrix, which together with the strong interfacial interaction between TPG and CSM contribute to the remarkable improvement in mechanical properties of the resulted composites. We envision that the present work offers a straightforward yet effective methodology for preparing high-performance elastomer/graphene composites via conventional melt compounding.

Enhanced Electrochemical Performance of a Tin−antimony Alloy/N‐Doped Carbon Nanocomposite as a Sodium‐Ion Battery Anode

AbstractA simple one‐pot process for producing 3.5 nm diameter uniformly dispersed SnSb nanoparticles on a nitrogen‐doped carbon composite (NC) is reported. An ethanol slurry of SnCl4, SbCl3, and nitrilotriacetic acid (NTA) is heated in air to 300 °C to form the mixed metal oxide NTA complex; heating to 650 °C under argon yields the SnSb/NC nanocomposites, comprising 3.5 nm diameter SnSb nanocrystals uniformly distributed in the conductive N‐doped carbon. After 200 cycles at a specific current of 0.1 Ag−1, the SnSb/NC nanocomposite sodium‐ion anode retains a reversible capacity of 244 mAh g−1. The similarly prepared Sn/NC and Sb/NC anodes retain lower capacities of 88 and 188 mAh g−1, respectively. The improved performance of the SnSb/NC electrode might be ascribed to the stepwise sodiation/desodiation process of Sn and Sb species in the SnSb/NC electrode, which could act as an inert buffer matrix for each other, according to the potentials, slowing the capacity fading.

High-Pressure Gasification of Coal Water Ethanol Slurry in an Entrained Flow Gasifier for Bioethanol Application

In this study, the gasification performance of coal water ethanol slurry (CWES) was estimated in a pilot-scale entrained flow gasifier. CWES was prepared by adding ethanol into coal water slurry (CWS) to estimate the gasification performance of bioethanol-contained coal water slurry. In comparison to CWS gasification, gasification with CWES showed a higher performance, such as composition of hydrogen and carbon monoxide, carbon conversion, cold gas efficiency, and total flow rate of syngas. In general, the gasification performance is directly associated with the carbon content of CWS, and it is very difficult to increase the carbon content of CWS while maintaining slurry viscosity to the atomizable level (2000 cP). However, in the case of CWES, the carbon content of slurry can be readily improved and the viscosity of slurry can be reduced at the same time. Thus, the improved carbon content of CWES led to a higher gasification performance than that of CWS. Moreover, if bioethanol is actually used for the preparation of CWES, carbon dioxide emission from gasification could be considerably diminished.

Gelcasting of Aluminum Nitride Ceramics

Aluminum nitride (AlN) ceramics has been prepared by nonaqueous gelcasting in air and sintering in nitrogen atmosphere. The influence of pH and dispersant on the ζ potential of AlN–ethanol slurry was studied. And the rheological behavior of the slurry was evaluated to optimize the dispersant content and solid loading. Concentrated AlN slurry (53.8 vol%) with low viscosity was prepared using polyethyleneimine as the dispersant. Sorbitol polyglycidyl ether and tetraethylenepentamine were used as gelling and hardening agents, respectively. A green body with a relative density of 63.3% was obtained. After sintering at 1800°C for 4 h, AlN ceramics with a relative density of 99.6% and a thermal conductivity of 200 W·(m·K)−1 were produced.

Controlled release of d-glucose from starch granules containing 29% free d-glucose and Eudragit L100-55 as a binding and coating agent

Waxy maize starch (100% amylopectin) granules were modified by reaction of the granules with glucoamylase in a minimum amount of water to give 29% (w/w) d-glucose inside the granules [Kim, Y.-K.; Robyt, J. F. Carbohydr. Res. 1999, 318, 129−134]. These granules were made into beads by dropping an ethanol slurry of starch and different amounts of Eudragit L100-55 in a constant ratio of 100:1 from a pipette onto Whatman 3MM filter paper. The starch beads were air dried and then repeatedly sprayed 0–12 times with 2.0% (w/v) Eudragit L100-55 in ethanol, with drying between each spraying, to coat the surface of the starch beads, giving different amounts of Eudragit L100-55 coating. Seven different kinds of beads, with different amounts of Eudragit L100-55 binding and coating agent, were obtained. The rates of release of d-glucose into water from the seven kinds of beads were inversely proportional to the amount of binding and coating agent. Bead type I, which was without any binding and coating gave a fast 100% release of d-glucose in 30 min. Beads II and III also gave a fast 100% release in 60 min and 90 min, respectively. Bead IV gave a near linear release of 97% d-glucose in 150 min; Bead V gave a 50% release in 120 min followed by the remaining 50% in 60 min; and Beads VI and VII gave a slow release of 10% and 4%, respectively, from 0 to 120 min, followed by a rapid 100% release from 120 to 180 min.

The Active Phase in the Direct Synthesis of H2O2 from H2 and O2 over Pd/SiO2 Catalyst in a H2SO4/Ethanol System

In an effort to determine the active state of supported palladium for the direct formation of H2O2 from H2 and O2, the catalytic behavior of Pd0/SiO2, PdO/SiO2 and partially reduced PdO/SiO2 was determined. The results obtained in an ethanol slurry, with chloride ions and H2SO4 being present, showed that the PdO/SiO2 catalyst was almost completely inactive for the formation of H2O2 at 10 °C. The Pd0/SiO2 catalyst exhibited the highest activity for H2O2 formation, and the PdO/SiO2 material, reduced under very mild conditions, exhibited an intermediate activity. The state of Pd on the three catalysts was characterized by XRD, TEM and XPS methods. Only Pd0 (the metal phase) and PdO were observed on Pd0/SiO2 and PdO/SiO2, respectively. As expected, with the partially reduced PdO/SiO2 catalyst, both Pd0 and PdO phases were evident. The TEM results revealed that the Pd0 particles decorated the larger PdO particles. The results reported here support the role of metallic palladium, rather than the oxide, as the active phase for the direct formation of H2O2.

Inhibition of lipid oxidation and dynamics of polyphenol content in mechanically deboned meat supplemented with sea buckthorn ( Hippophae rhamnoides) berry residues

Mechanically deboned meat (MDM) contains about 10 times more polyunsaturated fatty acids (PUFAs) and also more hemoproteins than hand deboned meat (HDM) and is essentially more susceptible to both chemical and biochemical oxidation. The oxidation, leading to the formation of potentially mutagenic and carcinogenic derivatives of PUFAs, can be inhibited by berry extracts rich in antioxidant polyphenols. Using the 2-thiobarbituric acid reactive substances (TBARS) method, we have established that the ethanol slurry of the juice-free solid residue of sea buckthorn ( Hippophae rhamnoides – SB) berries inhibits oxidation of unsaturated fatty acids, of both chicken and turkey MDM. The polyphenols, mainly flavonols, responsible for this inhibition, are comparatively stable during short-term cooking and 6-day storage of cooked SB-MDMs at +6 °C. About half of the polyphenols are lost, obviously oxidised, during the storage of the uncooked samples of turkey 2%SB-MDM at +6 °C. The loss of polyphenols is much smaller in the case of chicken MDM, which is characterised by an in situ lower content of fatty acids, including the polyunsaturated ones. The liquid chromatography–diode array detection–tandem mass spectrometry (LC–DAD–ESI-MS/MS) method was used for identification and ranking of the potent polyphenolic antioxidants in the berry residue.

Consolidation of Ethanol/Bentonite Slurry Injected in a Planar Fracture; Mathematical Modelling and Experiment

ABSTRACTEthanol/bentonite slurry is an alternative to the conventional cement-based material that may cause chemical disturbances to the host rock and the buffer material. In this study we carried out an experiment in which the ethanol/bentonite slurry was injected into a planar synthetic fracture at a constant rate. The pressure build-up due to the increase in viscosity of the bentonite ethanol slurry was observed and, eventually, consolidation of the slurry led to termination of the injection. A mathematical model was also developed to simulate the advection, dispersion and matrix dispersion of ethanol that contributed to the increase in viscosity of the ethanol/bentonite slurry, together with a Stoke's flow of the slurry before consolidation. Furthermore, applicability of the ethanol/bentonite slurry as a grouting material in a range of geological settings is discussed based on the result of a case study using the same model.

High surface area MoO 3/MgO: preparation by reaction of MoO 3 and MgO in methanol or ethanol slurry and activity in hydrodesulfurization of benzothiophene

High surface area MoO 3/MgO (200–300 m 2 g −1) catalysts were prepared and tested in hydrodesulphurization of benzothiophene. The new slurry impregnation method was used that overcome the problem of chemical and textural instability of MgO support in aqueous impregnation solution of ammonium heptamolybdate. Molybdena was deposited by the reaction of MgO with the slurry of MoO 3 in aqueous methanol or ethanol at room temperature. Small amount of water added to alcohol (4 and 6% for methanol and ethanol, respectively) did not hurt texture of MgO and accelerated the impregnation reaction. The method is a special case of equilibrium adsorption impregnation. The maximum (saturated) amount of MoO 3 deposited on MgO of surface area of about 250 m 2 g −1 was about 22 wt.% MoO 3. However, hydrodesulphurization activity increased linearly only up to the loading of 15–20 wt.% MoO 3. XRD confirmed that molybdena is deposited in finely dispersed form. Hydrodesulphurization activity of the best MoO 3/MgO samples was the same as activity of the reference industrial MoO 3/Al 2O 3 catalyst.

Lactate distribution in the blood during steady-state exercise

Lactate distribution in the blood during steady-state exercise. Med. Sci. Sports Exerc., Vol. 30, No. 9, pp. 1424-1429, 1998. Purpose: The purpose of this investigation was to examine the plasma to red blood cell (RBC) lactate concentration ([La]) gradient and RBC:plasma [La] ratio during 30 min of steady-state cycle ergometer exercise at work rates below lactate threshold(<LT = ~≈40% of peak cycle ergometer O2 uptake {V˙O2peak}) and above LT (≈70% of V˙O2peak). Methods: Eight subjects (cycling V˙O2peak = 41.6 ± 1.6 mL·kg−1·min−1; LT = 57.9 ± 1.2% V˙O2peak) performed 30 min of cycle exercise at intensities < and > LT. Blood samples were taken from a heated forearm vein, immediately cooled to 4°C in a dry-ice ethanol slurry, and centrifuged at 4°C to separate plasma and RBCs. Results: During >LT, plasma[La] rose to 8.8 ± 1.1 mM after 10 min and remained above 6 mM. RBC [La] (4.9 ± 0.7 mM) was significantly lower than plasma [La] at 10 min and remained lower throughout exercise. As a result, there was a sizable[La] gradient (≈3.5 mM) from plasma to RBC during most of >LT. In<LT, plasma [La] increased only slightly from rest (1.6 ± 0.2 mM) after 6 min (2.4 ± 0.3 mM) and then declined to ≈2 mM for the remainder of the trial. The plasma to RBC [La] gradient averaged ≈0.8 mM throughout<LT. Despite drastically different plasma to RBC [La] gradients in <LT and >LT, the ratio of RBC [La]:plasma [La] was the same for both (0.58 ± 0.02) and not significantly different from rest. Conclusions: These results refuted our hypothesis that the RBC:plasma [La] ratio would decrease at the onset of >LT exercise because of muscle lactate release exceeding the ability of RBCs to take up the lactate. Instead, there appears to be an equilibrium between plasma [La] and RBC [La] in arterialized venous blood from a resting muscle group as evidenced by the constant RBC [La]:plasma [La] ratio.

Lactate distribution in the blood during steady-state exercise.

The purpose of this investigation was to examine the plasma to red blood cell (RBC) lactate concentration ([La]) gradient and RBC:plasma [La] ratio during 30 min of steady-state cycle ergometer exercise at work rates below lactate threshold (<LT = approximately 40% of peak cycle ergometer O2 uptake ¿VO2peak¿) and above LT (approximately 70% of VO2peak). Eight subjects (cycling VO2peak = 41.6+/-1.6 mL x kg(-1) x min(-1); LT = 57.9 + 1.2% VO2peak) performed 30 min of cycle exercise at intensities < and > LT. Blood samples were taken from a heated forearm vein, immediately cooled to 4 degrees C in a dry-ice ethanol slurry, and centrifuged at 4 degrees C to separate plasma and RBCs. During >LT, plasma [La] rose to 8.8+/-1.1 mM after 10 min and remained above 6 mM. RBC [La] (4.9+/-0.7 mM) was significantly lower than plasma [La] at 10 min and remained lower throughout exercise. As a result, there was a sizable [La] gradient (approximately 3.5 mM) from plasma to RBC during most of >LT. In <LT, plasma [La] increased only slightly from rest (1.6+/-0.2 mM) after 6 min (2.4+/-0.3 mM) and then declined to approximately 2 mM for the remainder of the trial. The plasma to RBC [La] gradient averaged approximately 0.8 mM throughout <LT. Despite drastically different plasma to RBC [La] gradients in <LT and >LT, the ratio of RBC [La]:plasma [La] was the same for both (0.58+/-0.02) and not significantly different from rest. These results refuted our hypothesis that the RBC:plasma [La] ratio would decrease at the onset of >LT exercise because of muscle lactate release exceeding the ability of RBCs to take up the lactate. Instead, there appears to be an equilibrium between plasma [La] and RBC [La] in arterialized venous blood from a resting muscle group as evidenced by the constant RBC [La]:plasma [La] ratio.

Formation and Control of Agglomerates in Alumina Powder

High‐purity alumina powder with submicrometer particle size was colloidally dispersed and classified in either water or ethanol to remove agglomerates from as‐received powder. After the slurries were dried, fine alumina particles cohered to form agglomerates, which were “hard” when formed in a water slurry, and “soft” in an ethanol slurry. Firing of the powder compacts with “hard” agglomerates resulted in inhomogeneous microstructures, and homogeneous microstructures were formed with “soft” agglomerates. The reasons for their formation are discussed and experimentally confirmed. In the case of water slurry, a small amount of transition alumina reacted with water at low pH. After drying, alumina gels were formed and acted as a strong binder between α‐alumina particles to form “hard” agglomerates.