Methanol Ethanol Mixture Research Articles

Mechanical Interatomic Bond Formation in Ethanol and Methanol-Ethanol Mixture by Laser-Driven Shock Waves.

Molecules, which were predicted to be produced by C-C or C-O bond formation between ethanol molecules induced by a laser-driven shock wave, were identified by gas chromatography-mass spectrometry. Moreover, the laser irradiation of a methanol-ethanol mixture revealed the formation of C-C and C-O bonds between both components. Particularly, four hemiacetals (methoxymethanol, 1-methoxyethanol, ethoxymethanol, and 1-ethoxyethanol) were identified in the Ar-saturated alcohol samples, whereas acetalization dominated sufficiently in the CO2-saturated samples, significantly reducing the hemiacetals. It was verified that some molecules were produced by the dropout of an ethanol part during the C-C or C-O bond formation, supporting the contribution of laser-driven shock waves.

A simple and highly sensitive LC–MS workflow for characterization and quantification of ADC cleavable payloads

Antibody–drug conjugates (ADC) payloads are cleavable drugs that act as the warhead to exert an ADC’s cytotoxic effects on cancer cells intracellularly. A simple and highly sensitive workflow is developed and validated for the simultaneous quantification of six ADC payloads, namely SN-38, MTX, DXd, MMAE, MMAF and Calicheamicin (CM). The workflow consists of a short and simple sample extraction using a methanol-ethanol mixture, followed by a fast liquid chromatography tandem mass spectrometry (LC–MS/MS) analysis. The results showed that well-validated linear response ranges of 0.4–100 nM for SN38, MTX and DXd, 0.04–100 nM for MMAE and MMAF, 0.4–1000 nM for CM were achieved in mouse serum. Recoveries for all six payloads at three different concentrations (low, medium and high) were more than 85%. An ultra-low sample volume of only 5 µL of serum is required due to the high sensitivity of the method. This validated method was successfully applied to a pharmacokinetic study to quantify MMAE in mouse serum samples.

Where have all the polyphenols gone? Check your filter!

Wine represents a complex matrix of polyphenolic compounds. Polyphenols alter the sensory qualities of the wine, represent chemotaxonomic markers and are responsible for many of its health benefits. It is critical to accurately quantify these compounds, which are the subject of extensive current research. Quantification usually requires HPLC analysis, where the main step in sample preparation involves filtration. With the assumption that sample compounds remain on the syringe filter, this study investigated whether diluting the sample before filtration would enable a better recovery of polyphenols, yielding more accurate results. For this purpose, a red, rosé and white wine were diluted with 4 different solvents (water, methanol, ethanol and a 1:1 methanol-ethanol mixture) prior to filtration, and their polyphenolic composition was analyzed. Only 7 polyphenols present in low concentrations were not affected by dilution, while 38 compounds were all detected in higher concentrations when applying certain solvents, compared to undiluted wine. The methanol-ethanol mixture enabled the best flow of polyphenolics through the filter, while the water dilution showed that 30–40% of the sum of anthocyanins remained on the filter if a dilution step was not included in the sample preparation procedure. This study confirmed the need to incorporate a preliminary evaluation of the filtration step during sample preparation to improve the accuracy of subsequent HPLC analyses.

Structural properties of single-walled carbon nanotubes under extreme dynamic pressures

The structural behaviors of single-walled carbon nanotubes (SWNTs) along the radial direction are critical to the cross-sectional phase transition, elastic recovery, and band structure engineering. Previous static pressure studies have established a clear picture on the structural behaviors of SWNTs that governed by the Lévy-Carrier law. But when the pressurization becomes dynamic, there lacks a fundamental understanding of the structural properties of SWNTs along the radial direction. Here, different from static (< 1 GPa/s) and shock compression (> 107 GPa/s), we gain new insights on the phase transition, recovery dynamics and energy dissipation of SWNT bundles with a median diameter of dt ∼1.4 and ∼0.8 nm under modest dynamic pressures in two common pressure mediums (4:1 methanol-ethanol mixture, silicone oil). Upon single ramp compression (ramp rate in an order of magnitude of ∼10–103 GPa/s), the lineshape and intensity changes of Raman spectra induced by the dynamic effect of hydrostatic stress are commonly observed, suggesting different structural behaviors compared with static pressure results. Unexpectedly, the pressure-induced defects are not found in cyclic ramp compressions up to 105 cycles, showing high structural stability to dynamic loading. The corresponding recovery dynamics and energy dissipation mechanism of SWNTs under varying dynamic conditions are also discussed. By analyzing the shear strain potential, distinct dynamic effects of hydrostatic pressure on the SWNTs in two pressure mediums are quantitatively unveiled.

Structural transitions of 4:1 methanol–ethanol mixture and silicone oil under high pressure

A 4:1 (volume ratio) methanol–ethanol (ME) mixture and silicone oil are two of the most widely used liquid pressure-transmitting media (PTM) in high-pressure studies. Their hydrostatic limits have been extensively studied using various methods; however, the evolution of the atomic structures associated with their emerging nonhydrostaticity remains unclear. Here, we monitor their structures as functions of pressure up to ∼30 GPa at room temperature using in situ high-pressure synchrotron x-ray diffraction (XRD), optical micro-Raman spectroscopy, and ruby fluorescence spectroscopy in a diamond anvil cell. No crystallization is observed for either PTM. The pressure dependence of the principal diffraction peak position and width indicates the existence of a glass transition in the 4:1 ME mixture at ∼12 GPa and in the silicone oil at ∼3 GPa, beyond which a pressure gradient emerges and grows quickly with pressure. There may be another liquid-to-liquid transition in the 4:1 ME mixture at ∼5 GPa and two more glass-to-glass transitions in the silicone oil at ∼10 GPa and ∼16 GPa. By contrast, Raman signals only show peak weakening and broadening for typical structural disordering, and Raman spectroscopy seems to be less sensitive than XRD in catching these structural transitions related to hydrostaticity variations in both PTM. These results uncover rich pressure-induced transitions in the two PTM and clarify their effects on hydrostaticity with direct structural evidence. The high-pressure XRD and Raman data on the two PTM obtained in this work could also be helpful in distinguishing between signals from samples and those from PTM in future high-pressure experiments.

Improved biodiesel production from waste cooking oil with mixed methanol\u2013ethanol using enhanced eggshell-derived CaO nano-catalyst

In this report, the utilization of mixed methanol–ethanol system for the production of biodiesel from waste cooking oil (WCO) using enhanced eggshell-derived calcium oxide (CaO) nano-catalyst was investigated. CaO nano-catalyst was produced by calcination of eggshell powder at 900 °C and followed by hydration-dehydration treatment to improve its catalytic activity. The particle size, morphology, and elemental composition of a catalyst were characterized by using XRD, SEM, and EDX techniques, respectively. After hydration-dehydration the shape of a catalyst was changed from a rod-like to honeycomb-like porous microstructure. Likewise, average particle size was reduced from 21.30 to 13.53 nm, as a result, its surface area increases. The main factors affecting the biodiesel yield were investigated, accordingly, an optimal biodiesel yield of 94% was obtained at 1:12 oil to methanol molar ratio, 2.5 wt% catalyst loading, 60 °C, and 120-min reaction time. A biodiesel yield of 88% was obtained using 6:6 equimolar ratio of methanol to ethanol, the yield even increased to 91% by increasing the catalyst loading to 3.5 wt%. Moreover, by slightly increasing the share of methanol in the mixture, at 8:4 ratio, the maximum biodiesel yield could reach 92%. Therefore, we suggest the utilization of methanol–ethanol mixture as a reactant and eggshell-derived CaO as a catalyst for enhanced conversion of WCO into biodiesel. It is a very promising approach for the development of low-cost and environmentally friendly technology. Properties of the biodiesel were also found in good agreement with the American (ASTM D6571) fuel standards.

240-GHz Reflectometer-Based Dielectric Sensor With Integrated Transducers in a 130-nm SiGe BiCMOS Technology

This article presents a reflectometer-based on-chip dielectric sensor with integrated transducers at 240 GHz. The chip simplifies the measurement of a vector network analyzer (VNA) to sense the incident and reflected waves by using two heterodyne mixer-based receivers with a dielectric sensing element. Radio frequency (RF) and local oscillator (LO) submillimeter waves are generated by two frequency multiplier chains, respectively. Two back-to-back identical differential side-coupled directive couplers are proposed to separate the incident and reflected signals and couple them to mixers. Both transmission line and coplanar stripline transducers are proposed and integrated with reflectometer to investigate the sensitivity of dielectric sensors. The latter leads to a larger power variation of the reflectometer by providing more sufficient operating bands for the magnitude and phase slope of $S_{11}$ . The readout of the transducers upon exposure to liquids is performed by the measurement of their reflected signals using two external excitation sources. The experimental dielectric sensing is demonstrated by using binary methanol–ethanol mixture placed on the proposed on-chip dielectric sensor in the assembled printed circuit board. It enables a maximum 8 dB of the power difference between the incident and reflected channels on the measurement of liquid solvents. Both chips occupy an area of 4.03 mm2 and consume 560 mW. Along with a wide operational frequency range from 200 to 240 GHz, this simplified one-port-VNA-based on-chip device makes it feasible for the use of handle product and suitable for the submillimeter-wave dielectric spectroscopy applications.

The influence of binary mixtures' structuring on the calculation of Kirkwood-Buff integrals: A molecular dynamics study

The Kirkwood-Buff integrals (KBIs) provide a link between structuring on an atomic scale accessed by simulations and thermodynamics, which makes it a powerful tool for bridging the gap between microscopic and macroscopic quantities. Here we present the simulation study of the concentration dependence of KBIs for various types of binary ethanol mixtures which range from simple to complex. The thermodynamically ideal but extensively clustered methanol-ethanol mixture shows linearity in KBIs. The non-ideal mixtures, ethanol-water and ethanol-benzene, have the extrema in KBIs which are linked to the formation of the domains due to the association of molecules of the same species. We also explore some of the issues in KBI calculation, as KBI, a property of an open ensemble, is usually obtained by using the running integrals of a pair correlation function, calculated from the simulation of constant number of particles placed in a finite simulation box. The study includes a multifaceted analysis of the LP shift (J. Mol. Liq. 159, 52, 2011) and Ganguly and van der Vegt correction (J. Chem. Theory Comput. 9(3), 1347, 2013) of the radial distribution function, and compares different approaches in the computation of running KBI (J. Phys. Chem. Lett. 4(2), 235, 2013), both of which compensate for finite-size and ensemble effects. The results show how the best approach to the KBI calculation varies depending on the structural complexity of the simulated system.

Practical effects of pressure-transmitting media on neutron diffraction experiments using Paris–Edinburgh presses

ABSTRACT To understand the practical effects of pressure-transmitting media (PTM) on neutron diffraction using Paris–Edinburgh presses, diffraction patterns of MgO were collected to approximately 20 GPa using PTMs of Pb, AgCl, 4:1 methanol–ethanol (ME) mixture with and without heating, N2, and Ar. Hydrostaticity in the sample chamber estimated from the MgO 220 peak width improves in the order of Pb, AgCl, Ar, ME mixture, N2, and the heated ME mixture. Unlike previous results using diamond anvil cells, the unheated ME mixture is superior to Ar even after freezing, probably due to the cup on the anvil face. Considering these results and the sizable coherent scattering of Ne, which would show good hydrostaticity, we conclude that the ME mixture (preferably the heated one) is the best PTM in neutron experiments up to 20 GPa, while Ar can be substituted when a sample is reactive to alcohols.

Alcohol sensor based on gold-coated nanoporous anodic alumina membrane

We report a refractive index sensor consisting of a gold-coated nanoporous anodic alumina membrane on aluminium substrate that can distinguish between different kinds of alcohols such as methanol and ethanol due to their different refractive indices. The nanoporous volume allows the loading of liquids with low surface energy into its nanopores. Upon dipping one end of the membrane into the alcohol, the entire nanoporous surface experiences wetting. The wavelength shift of the Fabry–Perot resonating modes formed between the gold-coated nanoporous alumina surface and aluminium on the other side due to the changed effective refractive index form the basis of the sensor. The sensitivity of the nanosensor to the refractive index of the loaded liquid is sufficient to distinguish between different alcohols such as methanol, ethanol and isopropanol, and to detect about 5–10% of methanol in a methanol–ethanol mixture.

Efficient Separation of Ethanol-Methanol and Ethanol-Water Mixtures Using ZIF-8 Supported on a Hierarchical Porous Mixed-Oxide Substrate.

This work reports a new approach for the synthesis of a zeolitic imidazolate framework (ZIF-8) composite. It employs the direct growth of the crystalline ZIF-8 on a mixed-metal oxide support TiO2–SiO2 (TSO), which mimics the porous structure of Populus nigra. Using the natural leaf as a template, the TSO support was prepared using a sol–gel method. The growth of the ZIF-8 layer on the TSO support was carried out by the seeds and second growth method. This method facilitates the homogeneous dispersion of ZIF-8 crystals at the surface of the TSO composite. The ZIF-8@TSO composite adsorbs methanol selectively, mainly due to the hierarchical porous structure of the mixed oxide support. As compared with the as-synthesized ZIF-8, a 50% methanol uptake is achieved in the ZIF-8@TSO composite, with only 25 wt % ZIF-8 loading. IAST simulations show that the ZIF-8@TSO composite has a preferential adsorption toward methanol when using an equimolar methanol–ethanol mixture. An opposite behavior is observed for the as-synthesized ZIF-8. The results show that combining MOFs and mixed-oxide supports with bioinspired structures opens opportunities for synthesizing new materials with unique and enhanced adsorption and separation properties.

Structural and Physical Properties of ZrSi2 under High Pressure: Experimental Study and First-Principles Calculations.

Zirconium disilicide (ZrSi2) has been investigated experimentally and theoretically for its structural and physical properties at high pressures. In situ compression experiments demonstrate that at low pressure, ZrSi2 adopts the C49 structure (space group Cmcm), which persists up to 54.5 GPa at room temperature, and the unit cell of ZrSi2 along b-axis is at least twice as compressible as along a- and c-axis. A bulk modulus of 170.0 ± 0.7 GPa ( K'0 = 4) is derived from the compression experiment employing methanol-ethanol mixture as the pressure-transmitting medium. Diffraction line-width analysis suggests a yield strength of about 3.0 GPa for ZrSi2 under high pressures at room temperature. The first-principles calculations mostly agree with the experimental results, such as mechanical and dynamic stability and elastic anisotropy ( Kc > Ka ≫ Kb). However, predicted axial modulus Kb by modeling is significantly smaller than the experimentally determined value, resulting in a sizable discrepancy between experimental (170.0 GPa) and theoretical (121.0 GPa) bulk moduli.

A Fully Integrated Low-Power 30 GHz Complex Dielectric Sensor in a 0.25-$\mu$m BiCMOS Technology

This paper presents an integrated low-power dielectric sensor in K-band frequencies implemented in a $0.25 \mu \mathrm{m}$ SiGe BiCMOS process, including the sensing front-end and readout circuits. The sensor enables the measurement of both real and imaginary part of permittivity of the material under test (MUT). The MUT is exposed on the resonator component in a sensing oscillator, and the oscillator results in permittivity- and conductivity-dependent change in the output frequency and output power, respectively. The frequency information is translated into dc voltage using a frequency discriminator, and the output power is detected using a power detector. The sensor has been calibrated using iso-propanol, ethanediol, and acetone solutions. Methanol–ethanol mixture solutions, in steps of 25% of concentration change, have been used to demonstrate the functionality of the sensor. The selectivity is showed using methanol–ethanol mixtures with concentration differences of 5% around a mixture ratio of 50:50. The chip is $2.3 \text{mm}^{2}$ in size and consumes 60 mW power. The sensor measures complex permittivity within 3.7% accuracy for the real part and 4.3% for the imaginary part. As a compact and low-power solution, the sensor is a potential candidate for minimal invasive investigations of chemicals and bio-materials at mm-wave frequencies.

Transformation pathways and isothermal compressibility of a MTN-type clathrasil using penetrating and non-penetrating fluids

The high-pressure behavior of the natural MTN-type clathrasil chibaite was investigated with in situ single-crystal X-ray diffraction and Raman spectroscopy under hydrostatic pressures up to 10.3 GPa. The experiments were conducted in diamond-anvil cells using 4:1 methanol-ethanol mixture (ME), helium (He) and neon (Ne) as pressure-transmitting media. The pressure dependent unit-cell volumes of the room-pressure polymorph yield an isothermal bulk modulus KT0 = 25.75 (19) GPa for the compression in the non-penetrating ME fluid. Due to the penetration of the Ne and He atoms into the cages of the framework, the crystal structure is significantly stiffened resulting in KT0 = 42.5 (1.2) GPa (Ne) and KT0 = 58 (2) GPa (He). Under the influence of pressure both the evolution of the Raman spectra and the change in cell metrics indicate a distortion of the lattice without leading to a complete pressure-induced amorphization, as observed for many comparable porous structures. Compressed in the non-penetrating ME, the cubic Fd3¯m framework of chibaite undergoes a first transformation step in the pressure range between 1.7 GPa and 2.2 GPa and a second one between 3.9 GPa and 4.3 GPa. The accompanied formation of crystal domains did not allow a reliable determination of the distorted crystal structures. The unit-cell parameters might suggest a monoclinic metric for pressures >1.7 GPa and a monoclinic or tetragonal metric for pressures >3.9 GPa. However, in some samples even the co-existence of crystal domains of a different degree of lattice distortions has been proved.

Monitoring Collapse of Uniform Cylindrical Brushes with a Thermoresponsive Corona in Water.

We generated rod-like micelles of uniform length by living crystallization-driven self-assembly of a polyferrocenylsilane (PFS) block copolymer PFS26-b-POEGMA163 in a methanol-ethanol mixture and then transferred these micelles to water. The corona chains consisted of poly(oligoethylene glycol methacrylate) that had a lower critical solution temperature (LCST) of 40.5 °C in water. We used a combination of static (SLS) and dynamic (DLS) multiangle light scattering to determine the dimensions of these cylindrical brush micelles in solution. Measurements carried out in dilute solution in water over a series of temperatures from 23 to 50 °C showed that the collapse transition was broad and continuous, upon both heating and cooling. This response is different from the collapse transition of POEGMA163 homopolymer in water, which occurs over a very narrow temperature range. Thus, we show that the collapse transition of a cylindrical brush has important features in common with the collapse of a brush of thermoresponsive polymers on a planar surface.

Extending the single-crystal quartz pressure gauge up to hydrostatic pressure of 19 GPa

In situ high-pressure diffraction experiments on single-crystal α-quartz under quasi-hydrostatic conditions up to 19 GPa were performed with diamond-anvil cells. Isotropic pressures were calibrated through the ruby-luminescence technique. A 4:1 methanol–ethanol mixture and the densified noble gases helium and neon were used as pressure media. The compression data revealed no significant influence of the pressure medium at room temperature on the high-pressure behavior of α-quartz. In order to describe its compressibility for use as a pressure standard, a fourth-order Birch–Murnaghan equation of state (EoS) with parameters K T0 = 37.0 (3) GPa, K T0′ = 6.7 (2) and K T0′′ = −0.73 (8) GPa−1 was applied to fit the data set of 99 individual data points. The fit of the axial compressibilities yields M T0 = 104.5 (8) GPa, M T0′ = 13.7 (4), M T0′′ = −1.04 (11) GPa−1 (a axis) and M T0 = 141 (3) GPa, M T0′ = 21 (2), M T0′′ = 8.4 (6) GPa−1 (c axis), confirming the previously reported anisotropy. Assuming an estimated standard deviation of 0.0001% in the quartz volume, an uncertainty of 0.013 GPa can be expected using the new set of EoS parameters to determine the pressure.

Hydrostaticity of poly(methyl methacrylate) loaded in a diamond anvil cell for high-pressure study

Hydrostaticity of poly(methyl methacrylate) (PMMA) loaded in a diamond anvil cell (DAC) was investigated up to ∼10 GPa under two conditions, i.e., with and without pressure-transmitting medium. When PMMA was loaded in the DAC without methanol-ethanol mixture, one of the most widely-used pressure-transmitting media, hydrostatic pressure condition was not fulfilled having a pressure gradient. However, the Brillouin frequency shift of the longitudinal acoustic mode of PMMA exhibited nearly the same pressure dependence regardless of the loading condition whether it was loaded with or without the methanol-ethanol mixture. This suggests that the equation of state (pressure-density relationship) of PMMA, which is calculated by using the Brillouin frequency shift, can be obtained reliably without any pressure medium at pressures less than the solidification pressure of the liquid.

Structural properties of pressure-induced structural phase transition of Si-doped GaAs by angular-dispersive X-ray diffraction

Pressure-induced phase transitions in n-type silicon-doped gallium arsenide (GaAs:Si) at ambient temperature were investigated by using angular-dispersive X-ray diffraction (ADXRD) under high pressure up to around 18.6 (1) GPa, with a 4:1 (in volume ratio) methanol–ethanol mixture as the pressure-transmitting medium. In situ ADXRD measurements revealed that n-type GaAs:Si starts to transform from zinc-blende structure to an orthorhombic structure [GaAs-II phase], space group Pmm2, at 16.4 (1) GPa. In contrast to previous studies of pure GaAs under pressure, our results show no evidence of structural transition to Fmmm or Cmcm phase. The fitting of volume compression data to the third-order Birch–Murnaghan equation of state yielded that the zero-pressure isothermal bulk moduli and the first-pressure derivatives were 75 (3) GPa and 6.4 (9) for the B3 phase, respectively. After decompressing to the ambient pressure, the GaAs:Si appears to revert to the B3 phase completely. By fitting to the empirical relations, the Knoop microhardness numbers are between HPK = 6.21 and HA = 5.85, respectively, which are substantially smaller than the values of 7–7.5 for pure GaAs reported previously. A discontinuous drop in the pressure-dependent lattice parameter, N–N distances, and V/V0 was observed at a pressure of 11.5 (1) GPa, which was tentatively attributed to the pressure-induced dislocation activities in the crystal grown by vertical gradient freeze method.

Dynamic parameter estimation and optimization for batch distillation

This work reviews a well-known methodology for batch distillation modeling, estimation, and optimization but adds a new case study with experimental validation. Use of nonlinear statistics and a sensitivity analysis provides valuable insight for model validation and optimization verification for batch columns. The application is a simple, batch column with a binary methanol–ethanol mixture. Dynamic parameter estimation with an ℓ1-norm error, nonlinear confidence intervals, ranking of observable parameters, and efficient sensitivity analysis are used to refine the model and find the best parameter estimates for dynamic optimization implementation. The statistical and sensitivity analyses indicated there are only a subset of parameters that are observable. For the batch column, the optimized production rate increases by 14% while maintaining product purity requirements.

Thermal conductivity of methanol-ethanol mixture and silicone oil at high pressures

4:1 methanol-ethanol (ME) mixture and silicone oil are common, important pressure transmitting media used in high pressure diamond anvil cell (DAC) experiments. Their thermal conductivities and elastic properties are critical for modeling heat conduction in the DAC experiments and for determining thermal conductivity of measurement samples under extreme conditions. We used time-domain thermoreflectance and picosecond interferometry combined with the DAC to study the thermal conductivities and elastic constants C11 of the ME mixture and silicone oil at room temperature and to pressures as high as ≈23 GPa. We found that pressure dependence of the thermal conductivity of ME and silicone oil are both well described by the prediction of the minimum thermal conductivity model, confirming the diffusion of thermal energy between nonpropagating molecular vibrational modes is the dominant heat transport mechanism in a liquid and amorphous polymer. Our results not only provide new insights into the physics of thermal transport in these common pressure media for high pressure thermal measurements, but will also significantly extend the feasibility of using silicone fluid medium to much higher pressure and moderately high temperature conditions with higher measurement accuracy than other pressure media.