Triethylene Glycol Monoethyl Ether Research Articles

Rapid and simultaneous determination of nine volatile solvents in ink entries with improved gas chromatography

Volatile compounds such as alcohols and ethers are added into ballpoint pen inks, gel pen inks and water-based rollerball pen inks as humectants or solvents. The composition of solvents in inks and their amounts of evaporation are critical evidence for identifying the types of pens or dating ink entries. Relative quantification methods using gas chromatography (GC) or gas chromatography coupled to mass spectrometry (GC/MS) were employed to analyze alcohols and ethers in most previously reported studies, but they were not convenient for researchers of the same field to compare results. Besides, those methods are time-consuming, with an average time of 23−36 min per run. Therefore, in this work a rapid quantification method was established to simultaneously determine nine volatile solvents commonly existed in ink entries, including ethylene glycol, 1,2-propanediol, 1,3-propanediol, glycerol, diethylene glycol, triethylene glycol, benzyl alcohol, 2-phenoxyethanol (PE) and diethylene glycol monoethyl ether (DGME), while 1,3-butanediol was used as the internal standard. A GC system equipped with flame ionization detector (FID) was adopted to separate the nine target analytes. The analysis time was reduced to 9–12 min. The linearity of the calibration curves was good in the ranges of 10–3000 ng/cm for all target analytes, and Pearson correlation coefficients were all greater than 0.999. The results indicate that the established method provides sensitive, precise, and accurate quantification of nine volatile solvents in ink entries. What’s more, this method raises analytical efficiency greatly and has lower requirements of instruments, showing promising application in questioned document examination and ink dating.

In Silico Molecular Docking and Simulation Studies of Protein HBx Involved in the Pathogenesis of Hepatitis B Virus-HBV.

Current drug discovery involves finding leading drug candidates for further development. New scientific approaches include molecular docking, ADMET studies, and molecular dynamic simulation to determine targets and lead compounds. Hepatitis B is a disease of concern that is a life-threatening liver infection. The protein considered for the study was HBx. The hepatitis B X-interacting protein crystal structure was obtained from the PDB database (PDB ID-3MSH). Twenty ligands were chosen from the PubChem database for further in silico studies. The present study focused on in silico molecular docking studies using iGEMDOCK. The triethylene glycol monoethyl ether derivative showed an optimum binding affinity with the molecular target HBx, with a high negative affinity binding energy of −59.02 kcal/mol. Lipinski’s rule of five, Veber, and Ghose were followed in subsequent ADMET studies. Molecular dynamic simulation was performed to confirm the docking studies and to analyze the stability of the structure. In these respects, the triethylene glycol monoethyl ether derivative may be a promising molecule to prepare future hepatitis B drug candidates. Substantial research effort to find a promising drug for hepatitis B is warranted in the future.

Analytical pyrolysis of poly(dimethylsiloxane) and poly(oxyethylene) siloxane copolymers. Application to the analysis of sewage sludges

Dimethicone (poly(dimethylsiloxane), PDMS) and its copolymers bearing a poly(ethylene glycol) (PEG) side chain (PEG-12 dimethicone and PEG-8 dimethicone) are utilised as ingredients in personal care products. These materials along with bis-PEG-18 methyl ether dimethyl silane were analysed by Py-GC–MS. The pyrolysates of dimethicone was dominated by cyclic dimethyl siloxanes from D3 to over D10. Besides Dn, the pyrolysates of PEG-dimethicone were featured by the presence of linear dimethyl siloxanes Ln. Hydroxylated siloxanes were also tentatively identified. Pyrograms were also characterised by PEG oligomers with different terminal groups (hydroxyl, ethyl, ethenyl). The molecular structure of pyrolysis products from the combined structural units of PDMS and PEG could not be assigned. Internal standard calibration protocols using pyrolysis products of PEG-12 dimethicone (L6, L8, L9, and triethyleneglycol monoethyl ether) exhibited satisfactory linearity (R2 > 0.992) in the 0.75−58 μg range and repeatability (RSD < 15 %). Three samples of dried sewage sludge from a municipal water treatment plant were extracted with tetrahydrofuran and the extracts analysed by Py-GC–MS. The pyrograms were characterised by intense signals due to the lipid matrix (hydrocarbons, fatty acids, steranes, sterenes, sterols). Dn and Ln were identified indicative for the presence of siloxanes at levels around 60−290 μg gdw−1, while pyrolytic markers of PEG were not revealed. The recovery of PEG-12 dimethicone (17 μg) in spiked sample was 76 %. Galaxolide, galaxolide lactone and triclosan were identified in the pyrograms. The results of this study evidenced the potential of Py-GC–MS as a screening tool for the determination of cosmetic ingredients in sewage sludge.

Effect of Properties of Silver Nanoparticles Coated with Polar Material and the Antibacterial Activity on Marine Pathogenic Bacteria

Silver nanoparticles (Ag NPs) have become one of the current research hotspots and are used in many fields such as electrochemistry, energy, bioanalysis, and environmental monitoring, especially in the field of antibacterial research. In this study, we investigated the effect of properties of Ag NPs coated with polar materials. Ag NPs covered by a dispersant that was triethylene glycol monoethyl ether was stable and conquered the aggregation of Ag NPs. The effect of the dispersant on biocompatibility was explored through interaction experiments between Ag NPs and DNA sequence. The coated Ag NPs could adsorb DNA, and the fluorescence of FAM-DNA could be quenched by Ag NPs. The adsorption and desorption experiments of DNA showed that the order of DNA functional groups on the interaction process was phosphate&gt;T&gt;C&gt;A&gt;G. Moreover, we selected marine pathogenic bacteria to test the antibacterial effect of Ag NPs coated with a polar dispersant. The polar material had a certain inhibitory effect on the antibacterial activity of Ag NPs. However, small molecules such as bases could interact on the surface Ag NPs and release Ag+ to perform the antibacterial activity. The results could contribute to the further application of Ag NPs.

Efficient Perovskite Solar Cells over a Broad Temperature Window: The Role of the Charge Carrier Extraction

AbstractThe mechanism behind the temperature dependence of the device performance in hybrid perovskite solar cells (HPSCs) is investigated systematically. The power conversion efficiency (PCE) of the reference cell using [60]PCBM as electron extraction layer (EEL) drops significantly from 11.9% at 295 K to 7% at 180 K. The deteriorated charge carrier extraction is found as the dominant factor causing this degradation. Temperature dependent spectroscopy and charge transport studies demonstrate that the poor electron transport in the [60]PCBM EEL at low temperature leads to inefficient charge carrier extraction. It is further demonstrated that the n‐type doping of [60]PCBM EEL or the use of an EEL (fulleropyrrolidine with a triethylene glycol monoethyl ether side chain) with higher electron transport capability is an effective strategy to achieve HPSCs working efficiently over a broad temperature range. The devices fabricated with these highly performing EELs have PCEs at 180 K of 16.7% and 18.2%, respectively. These results support the idea that the temperature dependence of the electron transport in the EELs limits the device performance in HPSCs, especially at lower temperatures and they also give directions toward further improvement of the PCE of HPSCs at realistic operating temperatures.

Improved efficiency of NiOx-based p-i-n perovskite solar cells by using PTEG-1 as electron transport layer

We present efficient p-i-n type perovskite solar cells using NiOx as the hole transport layer and a fulleropyrrolidine with a triethylene glycol monoethyl ether side chain (PTEG-1) as electron transport layer. This electron transport layer leads to higher power conversion efficiencies compared to perovskite solar cells with PCBM (phenyl-C61-butyric acid methyl ester). The improved performance of PTEG-1 devices is attributed to the reduced trap-assisted recombination and improved charge extraction in these solar cells, as determined by light intensity dependence and photoluminescence measurements. Through optimization of the hole and electron transport layers, the power conversion efficiency of the NiOx/perovskite/PTEG-1 solar cells was increased up to 16.1%.

Chemically programmed ink-jet printed resistive WORM memory array and readout circuit

In this paper an ink-jet printed write once read many (WORM) resistive memory fabricated on paper substrate is presented. The memory elements are programmed for different resistance states by printing triethylene glycol monoethyl ether on the substrate before the actual memory element is printed using silver nano particle ink. The resistance is thus able to be set to a broad range of values without changing the geometry of the elements. A memory card consisting of 16 elements is manufactured for which the elements are each programmed to one of four defined logic levels, providing a total of 4294 967 296 unique possible combinations. Using a readout circuit, originally developed for resistive sensors to avoid crosstalk between elements, a memory card reader is manufactured that is able to read the values of the memory card and transfer the data to a PC. Such printed memory cards can be used in various applications.

Volumetric, viscosimetric and spectroscopic studies for aqueous solution of ethylene glycol monoethyl ether

As a continuation of the systematic study on thermodynamic properties for the aqueous solution of alkoxyethanols, this paper reports new measurements of densities and viscosities for the aqueous solution of ethylene glycol monoethyl ether (CH3CH2OCH2CH2OH) covering the whole composition range at T=(293.15, 303.15, 313.15, 323.15, 333.15) K under atmospheric pressure. The thermal expansion coefficient and Grunberg–Nissan interaction parameter were calculated. Excess properties including excess molar volumes, viscosity deviations, and excess energies of activation for viscous flow were calculated according to the experimental results. These data have been correlated by the Redlich–Kister type equations to obtain their coefficients and standard deviations. UV–vis spectra and fluorescence emission of probe pyrene were recorded to reflect molecular interactions and the polarity change of micro environment in an aqueous solution with varied concentration of ethylene glycol monoethyl ether. The results indicate that molecular interaction between ethylene glycol monoethyl ether and water is weaker than that between diethylene glycol monoethyl ether and triethylene glycol monoethyl ether with water.

Preparation of polymer gel dosimeters based on less toxic monomers and gellan gum

New polymer gel dosimeters consisting of 2-hydroxyethyl methacrylate (HEMA), triethylene glycol monoethyl ether monomethacrylate (TGMEMA), polyethylene glycol 400 dimethacrylate (9G), tetrakis (hydroxymethyl) phosphonium chloride as an antioxidant, and gellan gum as a gel matrix were prepared. They were optically analyzed by measuring absorbance to evaluate a dose response. The absorbance of the polymer gel dosimeters that were exposed to 60Co γ-rays increased with increasing dose. The dosimeters comprising HEMA and 9G showed a linear increase in absorbance in the dose range from 0 to 10 Gy. The dose response depended on the 9G concentration. For others comprising HEMA, 9G and TGMEMA, the absorbance of the polymer gel dosimeters drastically increased above a certain dose, and then leveled off up to 10 Gy. The optical variations in these polymer gel dosimeters were also induced by x-irradiation from Cyberknife radiotherapy equipment. Furthermore, the exposed region of the latter polymer gel dosimeter exhibited a thermo-responsive behavior.

Severe Poisoning After Accidental Pediatric Ingestion of Glycol Ethers

Human glycol ether poisonings are sparsely reported in the medical literature. We describe a healthy 22-month-old boy who accidentally drank up to 330 mL of brake fluid containing a 75% bleed of various glycol ethers (5%-50% polyethylene glycol monomethyl ether, 15%-40% triethylene glycol monoethyl ether, 1%-30% triethylene glycol monomethyl ether, 1%-25% triethylene glycol monobutyl ether, 1%-20% polyethylene glycol, monobutyl ether, 1%-20% triethylene glycol, and <10% of other glycol ethers). Within 4 hours, he became somnolent and developed a persistent metabolic acidosis. Thirty minutes later, he received 1 dose of fomepizole. Neither progression nor improvement in clinical or metabolic status was noted after the fomepizole. He received hemodialysis for 3 hours ∼8 hours after ingestion, and his symptoms resolved resulting in an uneventfully recovery.

Volumetric, acoustic and spectroscopic studies for binary mixtures of ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) with alkoxyalkanols at T = (288.15 to 318.15) K

Densities and speeds of sound have been measured for the binary mixtures of ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF 6] with ethylene glycol monoethyl ether (EGMEE), diethylene glycol monoethyl ether (Di-EGMEE), triethylene glycol monoethyl ether (Tri-EGMEE) over the whole composition range at atmospheric pressure. Experimental densities have been used to estimate excess molar volumes, V E . Changes in isentropic compressibility, Δκ s have been estimated by using experimental speed of sound and density values. Excess properties were fitted to the Redlich–Kister polynomial equation to obtain the binary coefficients and the standard errors. The molecular scale interactions between ionic liquid and alkoxyalkanols have been investigated through 1H NMR spectroscopy. NMR chemical shifts for hydroxyl group of alkoxyalkanols and their deviations show hydrogen bonding interactions of varying strengths between ionic liquid and alkoxyalkanol in their binary mixtures.

Application of the extended real associated solution (ERAS) model to excess molar volumes of binary mixtures of (alkoxyethanols + 1-alkanol)

Excess molar volumes of binary mixtures of diethylene glycol monomethyl ether or triethylene glycol monomethyl ether or diethylene glycol monoethyl ether or triethylene glycol monoethyl ether + 1-alkanol at 298.15 K and atmospheric pressure over whole composition range have been used for application of extended real associated solution (ERAS) model which accounts for hydrogen bonding effects as well as for free volume effects in associating mixtures. The ERAS model results obtained by adjusting the model parameters indicates strong hydrogen bonding effects between unlike molecules. The value of cross association constant K AB illustrates the fact that cross associates are more pronounced in mixture of lower 1-alkanol.

Density and Viscosity of the Binary Mixture of Triethylene Glycol Monoethyl Ether + Water from (293.15 to 333.15) K at Atmospheric Pressure

As part of our systematic program on the thermodynamic study of an aqueous solution of glycol ethers, this work reports new measurements of densities and viscosities for the binary liquid mixture of triethylene glycol monoethyl ether (CH3CH2(OCH2CH2)3OH) + water as a function of composition in the temperature range from (293.15 to 333.15) K at atmospheric pressure. Densities were determined using a capillary pycnometer. Viscosities were measured with an Ubbelohde capillary viscometer. From the experimental data, the excess molar volumes, VE, and viscosity deviations, δη, were calculated. These data have been correlated by the Redlich−Kister type equations to obtain their coefficients and standard deviations. The results suggest that the molecular interaction between triethylene glycol monoethyl ether and water is stronger than that of diethylene glycol monoethyl ether and water.

Excess molar volumes and excess molar enthalpies of the binary mixtures of 1,2-dichloropropane with di- and triethylene glycol mono-alkyl ethers at T = 298.15 K

The excess molar volumes V m E and excess molar enthalpies H m E at T = 298.15 K and atmospheric pressure for the binary systems of 1,2-dichloropropane (1,2-DCP) with di- and triethylene glycol mono-alkyl ethers have been determined by measuring density and heat flux, respectively. The density has been measured by using a digital vibrating-tube densimeter, whereas heat flux measurements have been carried out by using an isothermal calorimeter with a flow-mixing cell. The diethylene glycol mono-alkyl ethers are 2-(2-alkoxyethoxy)ethanols: diethylene glycol mono-propyl ether (DEGMPE), diethylene glycol mono-butyl ether (DEGMBE), and the triethylene glycol mono-alkyl ethers are 2-(2-(2-alkoxyethoxy)ethoxy)ethanols: triethylene glycol mono-methyl ether (TEGMME), triethylene glycol mono-ethyl ether (TEGMEE), and triethylene glycol mono-butyl ether(TEGMBE). It was found that both V m E and H m E values of the binary mixtures are negative over the whole composition range except for the mixture with very high mole fraction of 1,2-DCP( x 1) in both DEGMPE and DEGMBE. In the case of 2-(2-(2-alkoxyethoxy)ethoxy)ethanols, the negative values of V m E and H m E continue to increase with an increase of the alkyl chain length of these alkoxyethanols. The minimum values of V m E shift from −0.1939 cm 3 mol −1 for the mixture with DEGMPE to −0.40 cm 3 mol −1 for the mixture with TEGMBE at x 1 = 0.40–0.50. Also, the minimum negative values of H m E have been shown ranging from −472.9 J mol −1 (DEGMBE) to −800.5 J mol −1 (TEGMBE) at x 1 = 0.40–0.50. The experimental results of both H m E and V m E were fitted to the Redlich–Kister equation. The experimental H m E data were also fitted to three local-composition models (Wilson, NRTL, and UNIQUAC). It was found that among these three models, the NRTL equation provides the most appropriate correlating result.

Excess Molar Enthalpies and Hydrogen Bonding in Binary Mixtures Containing Ethers and Benzyl Alcohol at 308.15 K and Atmospheric Pressure

Excess molar enthalpies, , of binary liquid mixtures containing dibutyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol ethyl ether, diethylene glycol diethyl ether, or triethylene glycol monoethyl ether + benzyl alcohol have been measured over the entire range of composition at 308.15 K and at atmospheric pressure using a flow microcalorimeter. Data were fitted to the Redlich−Kister equation. The results show how the enthalpy of mixing is influenced by both the steric and electronic characteristic of the terminal groups that belong to the OP = [CH2OCH2] central unit of the ether and by the hydrogen bonding.

Preparation and Evaluation of Polyvinyl alcohol-co-oleylvinyl ether Derivatives as Tumor-Specific Cytotoxic Systems

A series of poly(vinyl alcohol) amphiphilic derivatives have been prepared to obtain polymeric aggregates in aqueous phase holding thermodynamic instability. The aim was to evaluate their ability to interact with tumor cells eliciting selective cytotoxicity. The poly(vinyl alcohol) derivatives were prepared by partial substitution of poly(vinyl alcohol) (MW 10 kDa) with both oleyl chains and poly(ethylene glycol) monoethyl ethers (PEGMEE) of different molecular weights. The substitution degree was 1.5% for the oleyl chains and 1% for the PEGMEE chains (moles of substituent per 100 mol of hydroxyvinyl monomer). The polyvinyl derivatives obtained easily dissolved in water. Dynamic and static light scattering measurements on the polymer aqueous solutions indicated the formation of polymeric aggregates characterized by low polydispersity (0.232-0.299) and mean size (218-382 nm) in the range suitable for intravenous administration. Moreover, they were characterized by different packing densities and thermodynamic instabilities driving the polymers to interact with hydrophobic membranes. Among the analyzed polymers, the poly(vinyl alcohol)-co-oleylvinyl ether substituted with triethylene glycol monoethyl ether (P10(4)) provided in solution the highest affinity for hydrophobic membranes. P10(4), moreover, was the most cytotoxic toward the tumor cell lines analyzed (neuroblastoma: SH-SY5Y, IMR-32, HTLA-230. melanoma: MZ2-MEL, RPMI7932.), while it did not appreciably alter the viability of the normal resting lymphocytes. The peculiar behavior of the P10(4) aggregates has been correlated to their high thermodynamic instability in solution due to the high packing density that triggers the polymeric aggregates to interact with hydrophobic membranes such as the tumor cell membranes, thus eliciting cytotoxicity.

A cohesion/tension model for the gating of aquaporins allows estimation of water channel pore volumes in Chara

ABSTRACTThe water permeability (hydraulic conductivity; Lp) of turgid, intact internodes of Chara corallina decreased exponentially as the concentration of osmolytes applied in the medium increased. Membranes were permeable to osmolytes and therefore they could be applied on both sides of the plasma membrane at concentrations of up to 2.0 m (5.0 MPa of osmotic pressure). Organic solutes of different molecular size (molecular weight, MW) and reflection coefficients (σs) were used [heavy water HDO, MW: 19, σs: 0.004; acetone, MW: 58, σs: 0.15; dimethyl formamide (DMF), MW: 73, σs: 0.76; ethylene glycol monomethyl ether (EGMME), MW: 76, σs: 0.59; diethylene glycol monomethyl ether (DEGMME), MW: 120, σs: 0.78 and triethylene glycol monoethyl ether (TEGMEE), MW: 178, σs: 0.80]. The larger the molecular size of the osmolyte, the more efficient it was in reducing cell Lp at a given concentration. The residual cell Lp decreased with increasing size of osmolytes. The findings are in agreement with a cohesion/tension model of the osmotic dehydration of water channels (aquaporins; AQPs), which predicts both reversible exponential dehydration curves and the dependence on the size of osmolytes which are more or less excluded from AQPs (Ye, Wiera &amp; Steudle, Journal of Experimental Botany 55, 449–461, 2004). In the presence of big osmolytes, dehydration curves were best described by the sum of two exponentials (as predicted from the theory in the presence of two different types of AQPs with differing pore diameters and volumes). AQPs with big diameters could not be closed in the presence of osmolytes of small molecular size, even at very high concentrations. The cohesion/tension theory allowed pore volumes of AQPs to be evaluated, which was 2.3 ± 0.2 nm3 for the narrow pore and between 5.5 ± 0.8 and 6.1 ± 0.8 nm3 for the wider pores. The existence of different types of pores was also evident from differences in the residual Lp. Alternatively, pore volumes were estimated from ratios between osmotic (Pf) and diffusional (Pd) water flow, yielding the number of water molecules (N) in the pores. N‐values ranged between 35 and 60, which referred to volumes of 0.51 and 0.88 nm3/pore. Values of pore volumes obtained by either method were bigger than those reported in the literature for other AQPs. Absolute values of pore volumes and differences obtained by the two methods are discussed in terms of an inclusion of mouth parts of AQPs during osmotic dehydration. It is concluded that the mouth part contributed to the absolute values of pore volumes depending on the size of osmolytes. However, this can not explain the finding of the existence of two different types or groups of AQPs in the plasma membrane of Chara.

A cohesion/tension mechanism explains the gating of water channels (aquaporins) in Chara internodes by high concentration.

Isolated internodes of Chara corallina have been used to study the gating of aquaporins (water channels) in the presence of high concentrations of osmotic solutes of different size (molecular weight). Osmolytes were acetone and three glycol ethers: ethylene glycol monomethyl ether (EGMME), diethylene glycol monomethyl ether (DEGMME), and triethylene glycol monoethyl ether (TEGMEE). The 'osmotic efficiency' of osmolytes was quite different. Their reflection coefficients ranged between 0.15 (acetone), 0.59 (EGMME), 0.78 (DEGMME), and 0.80 (TEGMEE). Bulk water permeability (Lp) and diffusive permeabilities (Ps) of heavy water (HDO), hydrogen peroxide (H2O2), acetone, and glycol ethers (EGMME, DEGMME, and TEGMEE) were measured using a cell pressure probe. Cells were treated with different concentrations of osmotic solutes of up to 800 mM ( approximately 2.0 MPa of osmotic pressure). Inhibition of aquaporin activity increased with both increasing concentration and size of solutes (reflection coefficients). As cell Lp decreased, Ps increased, indicating that water and solutes used different passages across the plasma membrane. Similar to earlier findings of an osmotic gating of ion channels, a cohesion/tension model of the gating of water channels in Chara internodes by high concentration is proposed. According to the model, tensions (negative pressures) within water channels affected the open/closed state by changing the free energy between states and favoured a distorted/collapsed rather than the open state. They should have differed depending on the concentration and size of solutes that are more or less excluded from aquaporins. The bigger the solute, the lower was the concentration required to induce a reversible closure of aquaporins, as predicted by the model.

Excess Molar Volumes and Excess Partial Molar Volumes of Triethylene Glycol Monomethyl Ether– n -Alcohol Mixtures at 25°C

We have measured excess molar volumes V m E of binary mixtures of triethylene glycol monoethyl ether with methanol, ethanol, 1-propanol, 1-pentanol, and I-hexanol over the full range of compositions at 25°C. The measurements were carried out with a continuous-dilution dilatometer. The excess molar volumes V m E are negative over the entire range of composition for the systems triethylene glycol monoethyl ether + methanol, + ethanol, and + 1-propanol and positive for the remaining systems, triethylene glycol monoethyl ether + 1-pentanol, and + 1-hexanol. The excess V m E increases in the positive direction with increasing chain length of the n-alcohol. The measured excess volumes have been compared to our previous published data with an effort to assess the effects of replacing methyl by ethyl groups and of inserting oxyethylene groups. The results have been used to estimate the excess partial molar volumes V m,i E of the components. The behavior of V m E and V m,i E with composition and the number of carbon atoms in the alcohol molecule is discussed.

Excess Molar Volumes and Excess Partial Molar Volumes of Triethylene Glycol Monomethyl Ether–n-Alcohol Mixtures at 25°C

We have measured excess molar volumes VEm of binary mixtures of triethylene glycol monoethyl ether with methanol, ethanol, 1-propanol, 1-pentanol, and 1-hexanol over the full range of compositions at 25°C. The measurements were carried out with a continuous-dilution dilatometer. The excess molar volumes VEm are negative over the entire range of composition for the systems triethylene glycol monoethyl ether + methanol, + ethanol, and + 1-propanol and positive for the remaining systems, triethylene glycol monoethyl ether + 1-pentanol, and + 1-hexanol. The excess VEm increases in the positive direction with increasing chain length of the n-alcohol. The measured excess volumes have been compared to our previous published data with an effort to assess the effects of replacing methyl by ethyl groups and of inserting oxyethylene groups. The results have been used to estimate the excess partial molar volumes VEm,i of the components. The behavior of VEm and VEm,i with composition and the number of carbon atoms in the alcohol molecule is discussed.