Isopropanol Concentration Research Articles

High Cr(VI) adsorption capacity of rutile titania prepared by hydrolysis of TiCl4 with AlCl3 addition

Rutile titania (TiO2) was successfully prepared via hydrolysis of TiCl4 in the presence of AlCl3. The powders were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) surface area analysis. In the present system, AlCl3 functions as a nucleating agent and induces the formation of rutile TiO2. The influences of HCl and isopropanol concentrations on the purity and morphology of the rutile TiO2 were investigated. The purity of the rutile TiO2 increased with increasing concentration of HCl. Evenly dispersed rutile TiO2 particles with a spherical morphology were obtained when the HCl and isopropanol concentrations were 0.5 and 1 mol·L−1, respectively. Furthermore, the prepared TiO2 powders were used in adsorption tests of the heavy metal pollutant Cr(VI). Rutile TiO2 sample S-9 demonstrated greater adsorption performance and a removal efficiency that was greater than 99.95% after 60 min of adsorption when the Cr(VI) concentration was 200 mg·L−1 The maximum adsorption capacity on rutile TiO2 was 28.9 mg·g−1. This work provides an easy path to prepare a high-performance rutile TiO2 adsorbent with potential applications in water pollution treatment.

Co-solvent exfoliation of layered titanium diboride into few-layer-thick nanosheets

In this work, we present an approach to nanoscale titanium diboride (TiB2), a layered ceramic from the metal diboride family, by investigating its interaction with a co-solvent containing water and isopropanol (IPA). It is gradually being established that layered metal diborides can be exfoliated in liquid phase to yield 2D counterparts. However, these reports have not yet systematically investigated the suitability of a solvent to exfoliate these ionic layered materials. Such a prospect is primarily limited by the fact that the theories available to rationally select exfoliating solvents are applicable only for van der Waals (vdW) layered materials. We show that it is possible to identify an optimal exfoliating medium for TiB2 by using co-solvents. We tested the exfoliation of TiB2 in isopropanol (IPA)-water co-solvent mixtures at different IPA concentrations, and established that a 10% isopropanol-water co-solvent results in optimal exfoliation. The resultant nanosheets are extremely thin (~3–5 nm) and exhibit a mild degree of oxy-functionalization. We observed that the original structural integrity of nanosheets (TiB2 lattice) is maintained to a large extent after exfoliation. We also validated the findings by using Surface Tension Component Matching (STCM) and studied the exfoliation of TiB2 in acetonitrile (ACN). This resulted in a lower degree of exfoliation as expected, but led us to obtain nearly pristine TiB2 nanosheets. The new physical insights presented in this work can serve as a guide to predict the exfoliation of TiB2 in other prospective solvents.

Highly efficient simultaneous catalytic degradation and defluorination of perfluorooctanoic acid by the H2O2-carbon/MnO2 system generating O2[rad]- and [rad]OH synchronously

Carbon/MnO2 composites including graphene/MnO2 and CNT/MnO2 were synthesized to treat perfluorooctanoic acid (PFOA) for the first time. Owing to the fast self-dispersion of carbon/MnO2 particles with H2O2 as the fuel, large solid surface area provided by carbon materials, and the effective simultaneous generation of OH and O2−, high PFOA degradation and defluorination efficiencies were achieved synchronously within 15 min. Interestingly, different OH scavengers showed opposite effects on PFOA degradation. The inhibition of PFOA degradation by nitrobenzene was due to the scavenging of OH resulting in the restraint of O2- generation. While the increasing PFOA degradation efficiency with the addition of high concentration of iso-propanol and tert-butyl alcohol was due to the less polarity of them than water resulting in the higher reactivity of O2−. Conclusively, the study provided a new alternative for the effective treatment of PFOA.

Microfluidic reflective-mode differential sensor based on open split ring resonators (OSRRs)

AbstractThis paper proposes a differential sensor based on a pair of open split ring resonators (OSRR) operating in reflection. The output signal is thus the differential reflection coefficient of both resonators, intimately related to their dielectric loading. Thus, for identical loads in both sensing resonators, the individual reflection coefficients are equal, thereby providing an ideally null output signal. By contrast, when unequal dielectric loads truncate the symmetry, the reflection coefficients are different, resulting in a differential output signal related to the level of asymmetry. In order to ease the measurement of the output signal, a rat-race hybrid coupler is used. The OSRR sensing loads are connected to the coupled ports of the hybrid coupler, whereas the input signal is injected to the Δ-port, and the output signal is collected at the isolated port (Σ-port). By this means, the output signal, i.e. the differential reflection coefficient between both sensing loads, is obtained from the transmission coefficient of a simple two-port structure. For experimental validation purposes, the sensor is applied to the measurement of isopropanol content in aqueous solutions, and for that purpose, the sensitive regions are equipped with microfluidic channels.

Multipurpose chemical liquid sensing applications by microwave approach.

In this work, a novel sensor based on printed circuit board (PCB) microstrip rectangular patch antenna is proposed to detect different ratios of ethanol alcohol in wines and isopropyl alcohol in disinfectants. The proposed sensor was designed by finite integration technique (FIT) based high-frequency electromagnetic solver (CST) and was fabricated by Proto Mat E33 machine. To implement the numerical investigations, dielectric properties of the samples were first measured by a dielectric probe kit then uploaded into the simulation program. Results showed a linear shifting in the resonant frequency of the sensor when the dielectric constant of the samples were changed due to different concentrations of ethanol alcohol and isopropyl alcohol. A good agreement was observed between the calculated and measured results, emphasizing the usability of dielectric behavior as an input sensing agent. It was concluded that the proposed sensor is viable for multipurpose chemical sensing applications.

Effect of the Isopropanol Impurity in the Feed on Catalytic Dehydration of Bioethanol to Ethylene

Isopropanol is one of the main organic impurities present in bioethanol. Effect of the isopropanol impurity in the feed on catalytic dehydration of 92% ethanol to ethylene over an aluminum oxide catalyst was studied in a gradientless reactor under the conditions of kinetic control at 350–400°С. The maximum permissible concentration of isopropanol in ethanol was found to be 0.7 g L–1, which is equivalent to 0.05 mol % in the gaseous feed. Such isopropanol concentration in the feed does not decrease the catalyst activity and selectivity to ethylene but suppresses formation of acetaldehyde, hydrogen, and butylene, improving the quality of the ethylene product. A bioethanol sample with ~0.15 g L–1 isopropanol content, produced from miscanthus using nitric acid treatment of the biomass, was tested. The process characteristics and ethylene quality obtained by the bioethanol dehydration are slightly higher because of decreased formation of by-products, compared with the dehydration of commercially available pure ethanol.

High Effective Composite RGO/TiO2 Photocatalysts to Degrade Isopropanol Pollutant in Semiconductor Industry

This research focused on the photodegradation of aqueous isopropanol in the presence of RGO/TiO2 photocatalysts, which were prepared by the hydrothermal method. Under the irradiation of the simulated sunlight AM1.5G, the photocatalytic activity of isopropanol degradation was studied. In addition, various initial isopropanol concentrations (20, 40, 60, 80, and 100 ppm) were employed in the photocatalytic reaction. P25RGO-0.01% was found to give the highest isopropanol removal of 92.24% at the initial isopropanol concentrations of 20 ppm. Such optimal loading of reduced graphene oxide can act as an electron trapping to suppress the possibility of the recombination of electron–hole pairs. Additionally, acetone was verified to be one of the main in1termediate products. Moreover, it was found that the acidic condition was advantageous to photodegrade isopropanol because of favorable conditions for forming hydroxyl radicals and superoxide radicals. The recyclability test was also verified by three sequent reactions and shown negligible decay of catalysts. This research demonstrated the feasibility of using photocatalysis to remove isopropanol wastewater in sunlight.

Dielectrophoretic analysis of the impact of isopropyl alcohol on the electric polarisability of Escherichia coli whole-cells

Whole-cell biocatalysts are versatile tools in (industrial) production processes; though, the effects that impact the efficiency are not fully understood yet. One main factor that affects whole-cell biocatalysts is the surrounding medium, which often consists of organic solvents due to low solubility of substrates in aqueous solutions. It is expected that organic solvents change the biophysical and biochemical properties of the whole-cell biocatalysts, e.g. by permeabilising the cell membrane, and thus analysis of these effects is of high importance. In this work, we present an analysis method to study the impact of organic solvents on whole-cell biocatalysts by means of dielectrophoresis. For instance, we evaluate the changes of the characteristic dielectrophoretic trapping ratio induced by incubation of Escherichia coli, serving as a model system, in an aqueous medium containing isopropyl alcohol. Therefore, we could evaluate the impact on the electric polarisability of the cells. For this purpose, a special microchannel device was designed and Escherichia coli cells were genetically modified to reliably synthesise a green fluorescent protein. We could demonstrate that our method was capable of revealing different responses to small changes in isopropyl alcohol concentration and incubation duration. Complementary spectrophotometric UV-Vis (ultraviolet-visible light) absorbance analysis of released NAD(P)+/NAD(P)H cofactor and proteins confirmed our results. Based on our results, we discuss the biophysical effects taking place during incubation.Graphical abstract

Development and intensification of a four-column hybrid process of heteroazeotropic distillation and pressure-swing distillation

This article develops a four-column hybrid process of hetero-azeotropic distillation and pressure-swing distillation (HAD-PSD) for separating a ternary multi-azeotropic mixture i.e., an organic aqueous solution with a low concentration of isopropanol (IPA) and diisopropylether (DIPE). For improving its economic and energetic performances, an intensified process by heat pump and dividing wall column is proposed, namely HAD-DWC-VRC-PSD. The quantified performance improvement over the HAD-PSD process reveals that the annual energy cost is drastically reduced by 39.7 % from 45.5–27.4 $ per tonne of IPA and DIPE while the total annual cost is cut by 11.7 % from 92.0–81.3 $ per tonne of IPA and DIPE. Besides, the thermodynamic efficiency is increased from 19.80 % to 25.96 %, and the carbon footprint as an indicator of unsustainable energy use is abated by 59 %. Overall, the HAD-DWC-VRC-PSD process is economically viable and eco-sustainable in a way.

Treatment of isopropanol wastewater in an anaerobic fluidized bed microbial fuel cell filled with macroporous adsorptive resin as multifunctional biocarrier

The isopropanol (IPA) wastewater was treated in an anaerobic fluidized bed microbial fuel cell (AFB-MFC) filled with macroporous adsorptive resin (MAR) particles as multifunctional biocarrier. MAR was used as a biological carriers and adsorbent. MAR was characterized by scanning electron microscope. The diffusion of isopropanol in MAR was studied by Materials Studio (MS) software, and diffusion coefficients were analyzed and calculated by molecular dynamics simulation. The simulation results were qualitatively consistent with the available experimental data. The diffusivity of IPA in MAR increased firstly, with the increasing IPA weight, and then decreased. The maximum diffusivity was resulted to be 0.3722 Å2/ps. In addition, the response surface methodology (RSM) and Box-Behnken design were used to study the effects of initial IPA concentration, flow rate and external resistance on performance of power output and pollutant degradation. The optimal experimental condition was observed as initial IPA concentration of 483.49 mg/L, a flow rate of 57.70 mL/min, and external resistance of 5225.78 Ω. After 21 h of operation under the optimized conditions, the maximum power density was 135.73 ± 0.17 mW/m2 and the COD removal was 68.21 ± 0.24%, which increased by 65.85% and 9.29%, respectively.

Impact of alcohol washing on the flavour profiles, functionality and protein quality of air classified pea protein enriched flour

In this study the potential of aqueous solvent washing on removing off-flavours in air classified pea protein-enriched flour (PPEF) was investigated. Unpleasant flavour compounds are one of the main deterrents to the application of pulses. PPEF was treated with ethanol or isopropanol at three different concentrations (20%, 50%, and 80%) to remove the volatiles related to unpleasant beany, earthy and astringent flavours. Headspace solid phase microextraction followed by GC-MS was used to identify the flavour compounds in untreated and treated PPEF. Besides the flavour profile, changes to their proximate composition, colour, functionality and protein quality were compared among untreated and treated samples. Higher concentrations of ethanol and isopropanol (50% and 80%) showed greater effectiveness in removing flavour compounds by reducing the total peak area by 82%–94%. Protein content in all treated samples (58.2%–64.3% d.b.) increased compared to untreated PPEF (55.5%) as a result of purification due to the decrease in ash, lipid and carbohydrate content. However, alcohol treatment reduced the protein solubility and oil holding capacity in all samples by 38.3%-75.9%, and 16.7%-30.2%, respectively. Although in vitro protein digestibility was improved with the solvent treatments, the amino acid scores of those samples became lower (i.e., reduced levels of methionine, cysteine or tryptophan) resulting in up to a 27.8% reduction in in vitro protein digestibility correct amino acid scores. Both ethanol and isopropanol at 50% and 80% concentration proved to be effective in removing flavour compounds in PPEF with some modifications on the chemical compositions, protein functionalities and quality.

Stable compensation voltages in differential mobility spectra by separating neutral vapors from ions in sample flow

In small planar differential mobility spectrometers with ambient pressure ion sources, both ions and neutral vapors of sample commonly flow from the ion source directly into and through the analyzer region. Although simple and convenient both for fabrication and operation, product ions derived from sample in this design may form clusters with neutral unreacted sample or matrix constituents particularly at vapor levels of 50 ppm or greater. Uncontrolled and changing levels of such neutrals cause concentration dependent formation of ion clusters with variations in compensation voltages of DMS spectra. Stable compensation voltages were achieved for product ions by extracting ions into a counter flow of purified gas excluding neutral vapors from ppm to percent levels. An interface with electric fields and purified air was placed between ion source and analyzer region and operated with both on-axis and orthogonal extraction of ions. Effectiveness of removal of neutrals was determined using variations in peak position for protonated monomers and proton bound dimers of dimethylmethylphosphate, significantly avoiding complications of ionization chemistry with high vapor concentrations of methylene chloride, iso-propanol, water, and methanol. In-silico modeling using COMSOL and SIMION clarified the flow of ions and gases in two modes of operation. Findings anticipate the development of multiple stages of DMS analyzers where vapors may be intentionally added as modifiers in one stage and removed before entering a subsequent stage.

Effect of non-solvent from the phase inversion method on the morphology and performance of the anode supported microtubular solid oxide fuel cells

The microstructure of the anode in anode-supported solid oxide fuel cells has significant influence on the cell performance. In this work, microtubular Ni-yttria stabilized zircona (Zr0.8 Y0.2O2, YSZ) anode support has been prepared by the phase inversion method. Different compositions of non-solvent have been used for the fabrication of the Ni-YSZ anode support, and the correlation between non-solvent composition and characteristics of the microstructure of the anode support has been investigated. The presence of ethanol or isopropanol in the non-solvent can inhibit the growth of the finger-like pores in the anode support. With the increase of the concentration of ethanol or isopropanol in the non-solvent, a thin dense layer can be observed on the top of the prepared tubular anode support. In addition, the mechanism of pore formation is explained based on the inter-diffusivity between the solvent and the non-solvent. The prepared microtubular solid oxide fuel cells (MT-SOFCs) have been tested, and the influence of the anode microstructure on the cell electrochemical performance is analyzed based on a polarization model.

Stereoselective synthesis of the key intermediate of ticagrelor and its diverse analogs using a new alcohol dehydrogenase from Rhodococcus kyotonensis

Bioreduction catalyzed by alcohol dehydrogenase/reductase is one of the most valuable biotransformation processes widely used in industry. The (S)-2-Chloro-1-(3, 4-difluorophenyl) ethanol is a key chiral synthon for synthesizing the antithrombotic agent ticagrelor. Herein, a new alcohol dehydrogenase (named Rhky-ADH) identified from Rhodococcus kyotonensis by an enzyme promiscuity-based genome mining method was successfully cloned and functionally expressed in Escherichia coli. The whole cell biocatalyst harboring Rhky-ADH was biochemically characterized and was shown to be able to convert 2-Chloro-1-(3, 4-difluorophenyl) ethanone to (S)-2-Chloro-1-(3, 4-difluorophenyl) ethanol with more than 99 % enantiomeric excess (ee) and 99 % conversion. Our data showed that the optimum temperature and pH for Rhky-ADH were 25 °C and pH 8.0, respectively. The addition of NADH and an appropriate concentration of isopropanol enhanced the activity of Rhky-ADH, and 1 mM Mn2+ increased the enzyme activity by about 8 %. Substrate specificity experiments showed that Rhky-ADH had notable enzyme promiscuity and could reduce several ketones with high stereoselectivity. Our investigation on this novel enzyme adds another rare biocatalyst to the toolbox for producing chiral alcohols, which are widely used in the pharmaceutical industry.

The characteristic of agarose extraction from dimethyl sulfide and isopropanol

Introduction. This study aimed to obtain agarose product with market standard quality which could be applied for electrophoresis. Methods. The material used in agarose extraction process was dried agar – agar bar extracted using dimethyl sulfide and soaked in isopropanol solution with 85%, 90%, and 95% of isopropanol concentration. The parameter which observed in this study was consisted of yield, water content, sulfate content, ash content, gel strength and electrophoresis gel. Results. The average score of agarose yield using different concentrations of isopropanol (IPA) was around 46.76% - 57.53% with the lowest yield of 46.76% and the highest yield of 57.53%. Meanwhile the average water content ranged from 18.32% to 18.64%. The average ash content was around 0.15% - 0.16% and the average sulfate content was 0.14% - 0.15%. The average strength of a 1% gel prepared in isopropanol was 1170 – 1183.33 gr/cm2. Best IPA concentration to soak agarose extract was on 95% concentration, with market standard characteristic as 57.54% of yield, 18.35% of water content, 0.14% of sulfate content, 0.15% of ash content and 1183.33 of gel strength. Conclusions.The application of electrophoresis of agarose gel showed that the bands of large molecular DNA fragment could not separate. Partially hydrolyzed protein samples had higher protein content, lighter color, and lower degree of denaturation and better functional properties compared to the traditional protein isolates.

Decontamination of Ceratocystis Pathogens Responsible for Rapid ʻŌhiʻa Death

Rapid ʻōhiʻa death (ROD) is caused by two recently described species of Ceratocystis, C. lukuohia and C. huliohia. These fungi are decimating ʻōhiʻa lehua (Metrosideros polymorpha), the keystone native tree species of Hawaiʻi. Viable Ceratocystis propagules can persist in ambrosia beetle frass (Coleoptera: Scolytinae), and movement of the frass may play a key role in the spread of the disease. In order to prevent the spread of ROD, we developed effective and practical surface (e.g., tools and shoes) decontamination methods to be used by researchers, managers, and the public alike. We first tested different household and laboratory disinfectants on the Ceratocystis fungi in culture, and then we applied the effective culture disinfectants to contaminated ambrosia beetle frass. Laboratory-grade ethanol (70, 80, and 95%), Clorox bleach (10%, 0.825% active ingredient [a.i.]), and isopropanol (70 and 91%), were all equally effective at decontaminating cultured C. lukuohia and C. huliohia. Although all concentrations of isopropanol (50, 70, and 90%) and ethanol (50, 70, and 90%) were effective disinfectants of Ceratocystis-contaminated frass, treatments of frass with up to 20% Clorox bleach (1.2% a.i.) were not completely adequate at killing the fungus. These data reveal that bleach is not a sufficient ROD disinfectant when frass is present, and isopropanol or ethanol are the more reliable options.

Correlation of osmolal gap with measured concentrations of acetone, ethylene glycol, isopropanol, methanol, and propylene glycol in patients at an academic medical center

The ingestion of toxic alcohols including methanol, ethylene glycol, and isopropanol remains a significant public health problem. These compounds can cause central nervous system depression and, for methanol and ethylene glycol, organ damage from toxic metabolites. The presence of these compounds in serum/plasma can often be determined and monitored by measuring the osmolal gap (OG). However, other compounds originating from endogenous or exogenous sources, such as propylene glycol and acetone, can also increase the OG. Conversion factors can be used to estimate specific concentrations of acetone and toxic alcohols from OG. In this retrospective study, data were analyzed for 260 samples originating from 158 unique patients that had determination of both OG and concentrations for toxic alcohols at an academic medical center central laboratory. Specific analysis included gas chromatography (acetone, isopropanol, methanol, ethylene glycol, propylene glycol) and/or enzymatic assay (ethylene glycol). Many samples also contained ethanol. The data was grouped by type of ingestion. The present study analyzed the relationship between the OG calculated from measured plasma/serum osmolality and the OG estimated by applying conversion factors to measured concentrations of the different compounds. The correlations tend to be linear and vary by compound, with methanol and ethylene glycol having the highest R2 values of 0.93 and 0.95, respectively, consistent with other published studies. Higher variability was seen for the data for isopropanol and acetone. For each of the data subsets, the estimated toxic alcohol concentration calculated using conversion factors from OG tends to overestimate the actual concentration of the compound. Overall, the present study demonstrates the generally linear relationship between OG determined by osmolality and the OG estimated using measured concentrations of acetone and toxic alcohols.

Effect of different conditions on pervaporation dehydration in CA/NYL66 blend membrane

In this study, cellulose acetate (CA) / nylon66 (NYL66) (95/5) blend membranes with different thicknesses were prepared by a solvent evaporation method. The effects of membrane thickness (almost 7-25 micrometre), feed concentration (70- 95 wt.% isopropanol), and feed temperature (30-60 C) were investigated on the performance of membrane in the separation of isopropanol-water mixtures. With regard to the results of sorption experiments, it was found that the increase of feed temperature enhanced the overall sorption while by increasing feed concentration, the overall sorption passed through a maximum value at 70 wt. % isopropanol (IPA) . The best separation factor 3080.51 was gained at high isopropanol concentration 95 wt.%, low feed temperature 30 C, and high membrane thickness 24.62 micrometre. Regarding the pervaporation separation index, the obtained results showed that proper values for the thickness of membrane, feed temperature, and isopropanol concentration in feed were 24.62 micrometre, 40 C, and 70 wt.%, respectively.

Effectiveness of vitamin D supplementation in Swedish children may be negatively impacted by BMI and serum fructose

In regions where sunlight exposure is limited, dietary vitamin D intake becomes important for maintaining status. However, Swedish children have been shown to have deficient or marginal status during the winter months even if the recommended dietary intake is met. Since low vitamin D status has been associated with several disease states, this study investigated the metabolic changes associated with improved vitamin D status due to supplementation.During the 3 winter months, 5–7-year-old children (n=170) in northern (Umeå, 63° N) and southern (Malmö, 55° N) Sweden were supplemented daily with 2 (placebo), 10 or 25 μg of vitamin D. BMI-for-age z-scores (BAZ), S-25(OH)D concentrations, insulin concentrations and the serum metabolome were assessed at baseline and follow-up.S-25(OH)D concentrations increased significantly in both supplementation groups (P<.001). Only arginine and isopropanol concentrations exhibited significant associations with improvements in S-25(OH)D. Furthermore, the extent to which S-25(OH)D increased was correlated with a combination of baseline BAZ and the change in serum fructose concentrations from baseline to follow up (P=.012). In particular, the change in S-25(OH)D concentrations was negatively correlated (P=.030) with the change in fructose concentrations for subjects with BAZ ≥0 and consuming at least 20 μg vitamin D daily. These results suggest that although the metabolic changes associated with improved vitamin D status are small, the effectiveness of dietary supplementation may be influenced by serum fructose concentrations.

Exploring molecular association of isopropanol-water binary solution by Raman spectroscopy

Raman spectra of isopropanol-water binary solution were measured at room temperature and atmospheric pressure in different blending ratios. We found that the hydrogen bonds between water molecules are almost unaffected by isopropanol molecules at low concentration of isopropanol. The symmetric and asymmetric OH stretching vibrations (corresponding to 3225 and 3443 cm-1Raman shift) of water move rapidly to high frequency when the volume fraction of isopropanol (Vi) exceeds 0.2, indicating the change of hydrogen bonds between isopropanol and water molecules. Moreover, the vibration force constant and the electron cloud density of isopropanol-water binary system were investigated due to the frequency shift of the CH3COH scissor vibration in the isopropanol Raman spectra. In addition, CH⋯O of the CH3group of isopropanol and the corresponding molecular association structure were investigated based on the Raman feature at 1452 cm−1. Finally, the phase transition process of association molecules (ring−CHain and chain) have been deeply explored in isopropanol-water binary solution by theoretical analysis.