Increasing Ethanol Concentration Research Articles

Role of ethanol concentration on drawing and infusion behavior of poly(ethylene terephthalate) filaments upon cold drawing

This paper describes the drawing and concomitant infusion behavior in low oriented PET filament drawn at room temperature in ethanol/water solution of various ethanol concentrations. Increasing concentration of ethanol greatly increased the number of necks on filament, and reduced the yield and drawing stresses. With increasing concentration of ethanol the infusion of ethanol into filament was increased, and a well-developed crystalline structure was formed. Shrinkage reduction of filament with increasing ethanol concentration was also investigated. Infusion of dye molecules in filament was also increased with raising of ethanol concentration. Color spectrum study confirmed that dye molecules infused only in drawn parts of filament and undrawn parts showed 100% transmittance.

Physiology, Genomics, and Pathway Engineering of an Ethanol-Tolerant Strain of Clostridium phytofermentans.

Novel processing strategies for hydrolysis and fermentation of lignocellulosic biomass in a single reactor offer large potential cost savings for production of biocommodities and biofuels. One critical challenge is retaining high enzyme production in the presence of elevated product titers. Toward this goal, the cellulolytic, ethanol-producing bacterium Clostridium phytofermentans was adapted to increased ethanol concentrations. The resulting ethanol-tolerant (ET) strain has nearly doubled ethanol tolerance relative to the wild-type level but also reduced ethanol yield and growth at low ethanol concentrations. The genome of the ET strain has coding changes in proteins involved in membrane biosynthesis, the Rnf complex, cation homeostasis, gene regulation, and ethanol production. In particular, purification of the mutant bifunctional acetaldehyde coenzyme A (CoA)/alcohol dehydrogenase showed that a G609D variant abolished its activities, including ethanol formation. Heterologous expression of Zymomonas mobilis pyruvate decarboxylase and alcohol dehydrogenase in the ET strain increased cellulose consumption and restored ethanol production, demonstrating how metabolic engineering can be used to overcome disadvantageous mutations incurred during adaptation to ethanol. We discuss how genetic changes in the ET strain reveal novel potential strategies for improving microbial solvent tolerance.

The Investigation of Thermodynamics and Combustion Properties of Alcohol-Gasoline Blends in an SI Engine

In this study, the thermodynamic properties, energy release, combustion, and emission variations in a spark ignition (SI) engine fueled with alcohol-gasoline blends and gasoline has been investigated. Test results showed that the net indicated work area of alcohol-gasoline blends was wider than pure gasoline blends and also; this situation affected positively the brake mean effective pressure and engine power output. The mass burn ratio of alcohol–gasoline blends was higher than those of pure gasoline. The exhaust emission level decreased with the increase of ethanol content in the fuel blend, but similar results was not observed with methanol–gasoline blends.

Low-concentration liquid sensing by an acoustic Mach–Zehnder interferometer in a two-dimensional phononic crystal

Mach–Zehnder interferometer formed by liquid-filled linear defect waveguides in a two-dimensional phononic crystal is numerically realized for sensing low concentrations of an analyte. The waveguides in the square phononic crystal of void cylinders in steel, as well as their T branches and sharp bends are utilized to construct interferometer arms. Sensing low concentrations of ethanol on the order of 0.1% in a binary mixture with water is achieved by replacing the contents of a number of waveguide core cells on one arm of the interferometer with the analyte. Computations are carried out through the finite-element method in an approach that takes the solid-liquid interaction at the waveguide core cells into account. Band analyses reveal linear variation of the central frequency of the transmission band within a band gap for ethanol concentrations up to 3.0%. Phase difference due to the imbalance of the sample and reference arms of the interferometer also varies linearly with ethanol concentration, leading in turn to a cosine variation of the Fourier component of the temporal interferometer response at the central input-pulse frequency. The induced phase difference in the investigated configuration becomes a and per percent increase of ethanol concentration as calculated from the band-structure and transient data, respectively. This is confirmed by transient finite-element simulations where totally destructive interference occurs for a concentration of approximately 1.5%. The proposed scheme, which can easily be adopted to other binary mixtures, offers a compact implementation requiring small amounts of analyte.

Crystallization behavior and mechanical properties of an electrospun ethanol‐mediated poly(ethylene terephthalate) fibrous membrane

ABSTRACTA simple approach for preparing electrospun poly(ethylene terephthalate) (PET) fibrous membranes with excellent spinnability and mechanical properties is introduced in this article. To enhance the electrospinnability of PET, a small content of ethanol was incorporated into a 16 wt % PET solution. The effects of ethanol on the solution properties, mechanical properties and crystallization properties and the related morphology were systematically evaluated. The conductivity (κ) measurement indicated that ethanol could obviously improve κ of the PET solution; this correlated well with the morphology of fibers. Scanning electron microscopy images showed that the diameter of the fibers decreased with increasing solution κ. The tensile strength of the PET fibrous membrane increased 1.8 times through the blending of 2.5 vol % ethanol with the PET solution. The differential scanning calorimetry results showed that the crystallinity was improved when the ethanol content increased; this was beneficial to the enhancement of the tensile strength. The glass‐transition temperature and melting temperature increased slightly, but the cold‐crystallization peak shifted to a lower temperature with increasing ethanol content (<3.75 vol %); this was attributed to the increasing in the oriented degree. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42341.

Ethanol and Isopropyl Alcohol Exposure Increases Biofilm Formation in Staphylococcus aureus and Staphylococcus epidermidis.

IntroductionAlcohols, including ethanol and isopropyl alcohol, are used in clinical practice for disinfection and infection prevention. Recent studies, however, demonstrate that alcohols may enhance biofilm production in Staphylococci.MethodsWe quantified biofilm formation in the presence of ethanol and isopropyl alcohol in six different, well-characterized strains of Staphylococcus epidermidis and Staphylococcus aureus. After 24 h of biofilm development, each strain was exposed to normal saline (NS), ethanol, or isopropyl alcohol (40%, 60%, 80% and 95%) for additional 24 h incubation. Adherent biofilms were stained and optical density was determined. Viability of strains was also determined after alcohol exposure.ResultsEthanol increased biofilm formation in all six strains compared to normal saline (p < 0.05). There was increased biofilm formation with increasing ethanol concentration. Isopropyl alcohol also increased biofilm formation with increasing alcohol concentration in all six strains (p < 0.01 vs NS). The slime-negative, chemical mutant strain of S. epidermidis increased biofilm formation after exposure to both alcohols, likely reverting back its primary phenotype through modulation of the intercellular adhesin repressor. All strains demonstrated viability after exposure to each alcohol concentration, though viability was decreased.ConclusionEthanol and isopropyl alcohol exposure increases biofilm formation of S. aureus and S. epidermidis at concentrations used in clinical settings. Ethanol and isopropyl alcohol did not eradicate viable Staphylococci from formed biofilm.Electronic supplementary materialThe online version of this article (doi:10.1007/s40121-015-0065-y) contains supplementary material, which is available to authorized users.

Synthesis, characterization and adsorption capability for Congo red of CoFe2O4 ferrite nanoparticles

CoFe2O4 ferrite nanoparticles are synthesized by an ethanol-assisted hydrothermal method, where the ethanol is mixed with water as the solution. In this synthesis, a rapid mixing of reducible metal cations with reducing agent and a simultaneous reduction process take place in a colloid mill. Synthesized ferrite samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and Raman spectroscopy. XRD patterns reveal the formation of CoFe2O4 ferrites with single spinel phase. SEM and TEM images show that the as-synthesized samples are with narrow size distribution. Raman spectroscopy studies clearly indicate the cation distribution in nanosized particles. Here, it is worthy to note that, with increasing ethanol content in ethanol–water mixed solution, an obvious superparamagnetic behavior of as-synthesized nanoparticles at room temperature is observed. The adsorption capability of the as-synthesized ferrite nanoparticles for Congo Red (CR) is examined. Enhancement of adsorption capability for CR with adding ethanol as the mixing solution is shown. The adsorption mechanism is discussed. This investigation reveals that the composition of ethanol/water mixed solution has great effects on the microstructure and magnetic properties as well as adsorption capacity of Congo Red (CR) dye of the as-synthesized CoFe2O4 ferrite samples.

Reducing β-glucosidase supplementation during cellulase recovery using engineered strain for successive lignocellulose bioconversion

Enzyme recycling by re-adsorption is one of the primary methods for reducing enzyme usage in lignocellulose conversion. This work proposes the combination of an engineered yeast strain that expresses β-glucosidase with enzyme recycling to reduce the amount of supplemented β-glucosidase in enzyme recycling experiments. Using the engineered strain, a slight increase in ethanol concentration was obtained after a 96-h fermentation of pretreated corncobs. Ethanol concentrations increased by 34.7% and 62.7% in the following two recycle rounds using the engineered strain compared with those using its parental strain without β-glucosidase addition. Furthermore, with the addition of β-glucosidase at 30CBU/g cellulose, the ethanol concentration after two recycle rounds exceeded 90% of that observed in the first SSF round with the engineered strain at a high initial cellulase loading of 45FPU/g cellulose.

Ethanol induces hydroxytyrosol formation in humans

Previous studies in animals have shown an increase of hydroxytyrosol (OHTyr), a potent phenolic antioxidant and a minor metabolite of dopamine (also called 3,4-dihydroxyphenylethanol or DOPET), after ethanol intake. The interaction between ethanol and dopamine metabolism is the probable mechanism involved. The aim of the study was to establish the contribution of the dose of ethanol on OHTyr formation. 24 healthy male volunteers were included. Subjects were distributed in three different cohorts and each volunteer received two doses of ethanol or placebo. Doses of ethanol administered were 6, 12, 18, 24, 30 and 42g. Study design was double-blind, randomized, crossover and controlled. Hydroxytyrosol, tyrosol (Tyr), 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) urinary excretion, ethanol plasma concentrations and drunkenness were evaluated along a 6-h period. Urinary excretion of OHTyr and Tyr increased with ethanol administered dose. A reduction in the ratio DOPAC/OHTyr from placebo to the highest dose was observed, compatible with a shift in the dopamine metabolism to preferently produce OHTyr instead of DOPAC. Also a dose-dependent increase in plasma ethanol concentrations and subjective effects was observed. This study demonstrates an endogenous production of OHTyr and Tyr in relation to ethanol administered dose in humans. Biological effects of both phenols from this source should be investigated in future studies.

Bioethanol from Dried Household Food Waste Applying Non-isothermal Simultaneous Saccharification and Fermentation at High Substrate Concentration

Household food waste (HFW) a complex biomass containing soluble sugars, lipids, proteins, cellulose, was used for bioethanol production at high substrate concentration and low enzyme loadings. HFW was subjected to microwave digestion (121 °C, 15 min) at 20 % (w/v) substrate concentration in the presence or absence of dilute sulfuric acid. The whole slurry was hydrolyzed and simultaneously saccharified and fermented using 5 and 10 FPU/g dry HFW. Enzymatic hydrolysis resulted in glucose yields in the range of 44–47 % of the theoretical (based on potential glucose content in the HFW) for both enzyme loadings tested, indicating that enzyme loadings lower than 10 FPU/g HFW could be used. During SSF tests the highest ethanol production (23.12 g/L) was obtained from the pretreated in the presence of dilute sulfuric acid HFW at 10 FPU/g HFW. In an attempt to protect the soluble fraction from possible decomposition and increase ethanol concentration, hot water treatment and higher substrate concentrations were examined. At optimal pretreatment conditions (100 °C, 60 min), glucose yields of 54.69 and 58.39 % (of the theoretical based on potential glucose content in the HFW) were achieved at 30 and 50 % w/v substrate concentration, respectively, which corresponds to an ethanol production of 17.44 and 31.03 g/L, respectively. In order to overcome the technical difficulties due to high initial viscosity of the material, when operating hydrolysis and fermentation at high initial substrate concentrations, a non-isothermal simultaneous saccharification and fermentation process operating in fed-batch mode was applied at 40 % (w/v) final substrate concentration, resulting in 42.66 g/L (or 107 g/kg HFW) ethanol production.

Defect-Controlled Gas Sensing Property of Nanostructured ZnO Films

Nanostructured ZnO films were fabricated by chemical vapor deposition (CVD) method with different Sn source concentrations for ethanol sensing application. It was found that the morphology of the ZnO films were obviously affected by Sn concentration, while no any Sn signals were detected in the films. The response of the nanostructured ZnO films increases with the increase of ethanol concentrations, and the S2 sample displays the highest sensitivity. Thephotoluminescence spectra show that more oxygen vacancies exist in the S2 sample than the other samples, which reveals that oxygen vacancies may play a great role to improve the gas sensing properties of the ZnO films.A possible sensing mechanism was proposed to explain these phenomena.This work provides a very simple and efficient method to prepare ZnO gas sensor, its high response and short recovery time are also a merit for the ZnO films used in gas sensor applications.

Alcohol dose dumping: The influence of ethanol on hot-melt extruded pellets comprising solid lipids

The objective of the present study was to investigate interactions between alcohol and hot-melt extruded pellets and the resulting drug release behavior. The pellets were composed of vegetable calcium stearate as matrix carrier and paracetamol or codeine phosphate as model drugs. Two solid lipids (Compritol® and Precirol®) were incorporated into the matrix to form robust/compact pellets. The drug release characteristics were a strong function of the API solubility, the addition of solid lipids, the dissolution media composition (i.e., alcohol concentration) and correspondingly, the pellet wettability. Pellets comprising paracetamol, which is highly soluble in ethanol, showed alcohol dose dumping regardless of the matrix composition. The wettability increased with increasing ethanol concentrations due to higher paracetamol solubilities yielding increased dissolution rates. For pellets containing codeine phosphate, which has a lower solubility in ethanol than in acidic media, the wettability was a function of the matrix composition. Dose dumping occurred for formulations comprising solid lipids as they showed increased wettabilities with increasing ethanol concentrations. In contrast, pellets comprising calcium stearate as single matrix component showed robustness in alcoholic media due to wettabilities that were not affected by the addition of ethanol.The results clearly indicate that the physico-chemical properties of the drug and the matrix systems are crucial for the design of ethanol-resistant dosage forms. Moreover, hydrophobic calcium stearate can be considered a suitable matrix system that minimizes the risk of ethanol-induced dose dumping for certain API’s.

Surface activity of octanoic acid in ethanol-water solutions from molecular simulation and experiment.

The surface activity of a typical surfactant, octanoic acid (OA), in ethanol-water solutions is investigated with a combined experimental and molecular simulation approach. The experiments show that OA reduces the surface tension of ethanol-water solutions at low ethanol concentration, but the effectiveness decreases with increasing ethanol concentration and vanishes for ethanol concentrations above 60%. Molecular dynamics simulations are used to obtain free energy landscapes for OA as a function of the distance from the surface. The free energy driving force pushing OA to the surface decreases with increasing ethanol concentration, and becomes insignificant (i.e., less than kT) for ethanol concentrations above 70%. Thus, the decrease in the effectiveness of OA in reducing the surface tension at higher ethanol concentrations can be attributed to the decrease in the free energy driving force keeping OA at the surface. We expect these results to apply generally to hydrocarbon-based surfactants.

Improved performance of a shielded torch using ethanol in inductively coupled plasma–sector field mass spectrometry

To improve the accuracy and precision of trace element analysis, higher analytical sensitivity and lower interference are required. In this study, we investigated the effects of the addition of ethanol in combination with a shielded torch on the signal intensities of elements from 7Li to 238U, oxide yields, doubly charged ion yields, isobaric interferences and ion distributions in inductively coupled plasma–sector field mass spectrometry (ICP–SFMS). For the 39 investigated elements in this study, using the shielded torch increases the sensitivity by a factor of 17–58. The well-known drawback of using a shielded torch is that it will increase the oxide yield. In this study, the CeO+/Ce+ ratio is increased by a factor of 3.3 in the GE-on mode compared to that in the GE-off mode at normal conditions (without ethanol). In the GE-on mode, the addition of 4% ethanol in ICP–SFMS is found not only to decrease the CeO+/Ce+ ratio by a factor of 4 but also to suppress the Ce2+/Ce+ ratio by a factor of 4.2. In large contrast, the effect of 2–6% ethanol on the oxide yield and doubly charged ratio is minimal in the GE-off mode. Except for As, Se, Sb, Te and Au, for which the signal intensities are increased by a factor of 1.4–3.7 in the presence of 2–6% ethanol, an increased concentration of ethanol suppresses intensities of other elements. In the GE-off mode, the suppression of the analyte signal due to increased ethanol concentration is more significant than that in the GE-on mode. Compared to the spatial profiles of the ion distributions in the normal mode (without ethanol), the addition of 2–4% ethanol leads to significantly wider axial and radial profiles. The significantly wider axial and radial ion distribution had a dilution effect on the ion densities, which subsequently reduced the ion signal intensities. The addition of 4% ethanol was also found to suppress the interferences of Xe by a factor of 2.8 and increase the sensitivity of Te determination in ICP–SFMS by a factor of 2.1 relative to the values obtained in conventional 2% (v/v) HNO3 solution at the corresponding optimum operating conditions in the GE-on mode. The addition of 4% ethanol in combination with the GE-on mode was successfully applied to the direct determination of nanogram levels of Te in a series of geological reference materials.

Monopersulfate oxidation of tetrabromobisphenol A by an iron(III)-phthalocyaninetetrasulfate catalyst coordinated to imidazole functionalized silica particles

An iron(III)-phthalocyaninetetrasulfate (FePcTS) was axially coordinated to a series of imidazole functionalized silica, 3-(1-imidazolyl)propylcarbamoyl-3′-aminopropylsilica (IPS) particles. Among the prepared FePcTS/IPS catalysts, catalytic activity for the oxidation of tetrabromobisphenol A (TBBPA) for the smallest sized particle (<30μm) was more effective than larger sizes (145μm< and 45–145μm). The catalytic activity of FePcTS/IPS was compared with that of a structural analogue, iron(III)-tetrakis(p-sulfonatephenyl)porphyrin (FeTPPS) supported IPS (FeTPPS/IPS). The TOF values for the oxidation of TBBPA by FePcTS/IPS (11–17h−1) were much larger than the corresponding values for FeTPPS/IPS (0.7–3.5h−1) in the absence and presence of humic acid, a major coexistent substance in landfill leachates. To investigate the reasons for the differences in catalytic activities between the FePcTS and FeTPPS systems, the influence of ethanol, a SO4− scavenger, on the oxidation of TBBPA oxidation was tested. The TOF values for FePcTS/IPS decreased with increasing ethanol concentration, while the catalytic activities for FeTPPS/IPS were not affected by adding ethanol. These results suggest that the higher catalytic activity of the FePcTS catalytic system can be attributed to the contribution of radical species, which can be generated via the homolysis of OO bonding in the Fe(III)-peroxo species.

Liquid–liquid equilibrium data and thermodynamic modeling for systems related to the production of ethyl esters of fatty acids from soybean soapstock acid oil

We obtained liquid–liquid equilibrium (LLE) data for the systems involved in biodiesel production from a low-value feedstock, namely fatty acids from soybean soapstock acid oil (FA-SSAO), at 303.2 and 323.2K. The systems studied were water+ethanol+FA-SSAO and water+ethanol+fatty acid ethyl esters (EE-SSAO). The mass fractions of the compounds in equilibrium in the two phases were determined analytically, whereas the binodal curves were obtained by the cloud-point method. The increase in temperature from 303.2 and 323.2K slightly increased the miscibility of the EE-SSAO system. We found that ethanol is more soluble in water than in either FA-SSAO or EE-SSAO, and that an increase in ethanol content in either the FA-SSAO-rich phase or the EE-SSAO-rich phase enhances water solubility in these phases. The experimental data were satisfactorily modeled by the NRTL and UNIQUAC approaches.

In vitro anti-cancer activity of ethanolic extract of Momordica charantia on cervical and breast cancer cell lines

Objectives: To estimate the total phenol content (TPC) of the ethanolic extract of Momordica charantia (EEMC) whole fruit and to study the cytotoxic activity of this extract against cell lines representing carcinomas of cervix and breast. Materials and Methods: Cervical and breast carcinoma cell lines (HeLa and MCF-7) were procured from National Center for Cell Sciences, Pune, and cultured in Dulbecco's modified eagle medium (DMEM) supplemented with 10% fetal bovine serum (FBS) and 1 mM L-glutamine. EEMC was prepared by graded ethanol fractionation method and the TPC determined using Folin–Ciocalteu assay. For cytotoxicity studies, 5000 cells/well in 100 μl DMEM-10% FBS medium were seeded in a 96 well plate; and treated with increasing concentration of EEMC. Efficacy of EEMC was determined by measuring the cell number using sulforhodamine B assay. Percentage inhibition was calculated using dimethyl sulfoxide vehicle control. The IC (50) value was calculated from the plot of inhibition (%) in dose- and time-dependent manner using GraphPad PRISM software. Results: The total phenolic content of EEMC decreased with increasing ethanol concentration from 50% to 100%. Cytotoxicity studies identified 50% ethanolic extract as the most active fraction. A time- and dose-dependent increase in the efficacy of 50% ethanolic extract for inhibiting cervical and breast carcinoma cell growth was noticed. The IC (50) dose was 12.31 μg/ml and 0.769 μg/ml for 50% EEMC at 48 h incubation for HeLa and MCF-7 cell lines, respectively. Conclusion: The presence of high total phenolic acid content in 50% ethanolic extract indicates that the anti-cancer activity of Momordica charantia could be due to the secondary metabolites. Based on the IC (50) value we conclude that the 50% EEMC is more potent against breast cancer cell lines. Further studies are required to know the exact cause for the increase in cell inhibition at 48 h incubation than in 72 h.

Conductometric study of nickel chloride in ethanol-water mixed solvent media at various temperatures

The conductivity measurement of nickel chloride has been done in binary solvent of the ethanol-water system. The different percentage of ethanol including 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 (v/v) has been chosen as binary solvents. The concentration of the electrolyte in the prepared solutions varies from 0.008 to 0.1 mol.l-1 for temperatures 298.15 K, 303.15 K and 308.15 K. The conductivity of the electrolyte decreases with increase in ethanol content in the solvent at a particular temperature, which is due to the decrease in dielectric constant of the medium. The conductivity increases with increase in temperature and concentration, due to increase in mobility of ions and number of ions from observed electrolyte respectively. DOI: http://dx.doi.org/10.3126/bibechana.v12i0.11789BIBECHANA 12 (2015) 128-134

Optimization of the ethanol recycling reflux extraction process for saponins using a design space approach.

A solvent recycling reflux extraction process for Panax notoginseng was optimized using a design space approach to improve the batch-to-batch consistency of the extract. Saponin yields, total saponin purity, and pigment yield were defined as the process critical quality attributes (CQAs). Ethanol content, extraction time, and the ratio of the recycling ethanol flow rate and initial solvent volume in the extraction tank (RES) were identified as the critical process parameters (CPPs) via quantitative risk assessment. Box-Behnken design experiments were performed. Quadratic models between CPPs and process CQAs were developed, with determination coefficients higher than 0.88. As the ethanol concentration decreases, saponin yields first increase and then decrease. A longer extraction time leads to higher yields of the ginsenosides Rb1 and Rd. The total saponin purity increases as the ethanol concentration increases. The pigment yield increases as the ethanol concentration decreases or extraction time increases. The design space was calculated using a Monte-Carlo simulation method with an acceptable probability of 0.90. Normal operation ranges to attain process CQA criteria with a probability of more than 0.914 are recommended as follows: ethanol content of 79–82%, extraction time of 6.1–7.1 h, and RES of 0.039–0.040 min−1. Most of the results of the verification experiments agreed well with the predictions. The verification experiment results showed that the selection of proper operating ethanol content, extraction time, and RES within the design space can ensure that the CQA criteria are met.

Evaporation of sessile droplets affected by graphite nanoparticles and binary base fluids.

The effects of ethanol component and nanoparticle concentration on evaporation dynamics of graphite-water nanofluid droplets have been studied experimentally. The results show that the formed deposition patterns vary greatly with an increase in ethanol concentration from 0 to 50 vol %. Nanoparticles have been observed to be carried to the droplet surface and form a large piece of aggregate. The volume evaporation rate on average increases as the ethanol concentration increases from 0 to 50 vol % in the binary mixture nanofluid droplets. The evaporation rate at the initial stage is more rapid than that at the late stage to dry, revealing a deviation from a linear fitting line, standing for a constant evaporation rate. The deviation is more intense with a higher ethanol concentration. The ethanol-induced smaller liquid-vapor surface tension leads to higher wettability of the nanofluid droplets. The graphite nanoparticles in ethanol-water droplets reinforce the pinning effect in the drying process, and the droplets with more ethanol demonstrate the depinning behavior only at the late stage. The addition of graphite nanoparticles in water enhances a droplet baseline spreading at the beginning of evaporation, a pinning effect during evaporation, and the evaporation rate. However, with a relatively high nanoparticle concentration, the enhancement is attenuated.