Propylene Glycol Monomethyl Ether Research Articles

Cu/Zn phthalocyanine dyes with up to 40% solubility in propylene glycol monomethyl ether acetate (PGMEA) for color filters

Color filters play an important role in the quality of complementary metal–oxide–semiconductors and thin-film-transistor liquid-crystal displays. Although pigment nanoparticles have traditionally been used as color filter colorants, the use of molecular dyes for preparing high-quality color filters is an emerging strategy. However, few studies have investigated the relation between the structure of dyes and their color filter characteristics, such as solubility, and thermal stability and photostability. In this study, six phthalocyanine dyes with different branched substituents and central metals (zinc and copper) were developed. These dyes displayed high levels of solubility in propylene glycol monomethyl ether acetate (up to 40.8 wt%), high light transmission, and satisfactory thermal stability and photostability, indicating their potential application in color filters. They may provide a way to explore more molecular dyes for color filters with excellent dissolution properties.

Effects of exposition to glycol ethers on heart rate recovery, parasympathetic modulation and oxygen diffusion at rest and during exercise

Introduction Daily exposition to ether glycols is common. Caretakers using cleaning products are critically exposed by combining physical activity with exposition to highly concentrated products. Previous animal studies showed hemato-, respiratory and autonomic nervous system toxicity amongst others. Yet, no controlled study explored the combination of an exposition to glycol ethers with physical activity in humans. Methods 30 young healthy participants were exposed a control condition (ambient air) and to one of three vaporized glycol ethers: propylene glycol n-propyl ether (PGPE, 25 ppm, n = 10) or propylene glycol ethyl ether (PGEE, 35 ppm, n = 10) or propylene glycol monomethyl ether (PGME, 35 ppm, n = 10) in a single-blind cross-over design. They performed an orthostatic test (5-min supine, 5-min standing) and a 6-min steady-state exercise at 1.5 W/kg followed by 10-min recovery in PGPE/PGEE conditions. In addition, an incremental exercise to exhaustion followed in PGME condition. Heart rate variability (HRV) was measured throughout the protocol, Heart rate recovery (HRR) was assessed during the 10-min recovery post steady-state exercise. Root-mean-square of the successive differences (RMSSD), power spectrum of the low- (LF) and high-frequency (HF) bands, tau, amplitude and T30 were computed for HRR. Near Infrared spectroscopy (NIRS) and cardiac output (using thoracic impedance) were measured for PGME exposition. PO2, PCO2 and pH were measured regularly via arterialized and venous blood sampling. Results Resting values of supine LF (1,180 ± 851 vs. 2,993 ± 2,259 ms2) and standing RMSSD (32 ± 17 vs. 41 ± 17 ms) increased under PGEE. Supine and standing HR decreased under PGPE (65.5 ± 4.8 vs. 61.3 ± 6.9 and 83.8 ± 7.0 vs. 76.1 ± 10.0 bpm) whereas standing RMSSD (26.6 ± 10.0 vs. 37.0 ± 14.9 ms) and LF (825 ± 474 vs. 2,028 ± 1,471 ms2) increased. Parasympathetic reactivation (e.g., RMSSD, LF and HF) was increased post-exercise under exposition to all three glycol ethers. In addition, amplitude significantly increased when exposed to PGEE. However, unexpectedly, HRR was neither slowed nor speeded. Finally, no differences were observed in any NIRS variables or cardiac output. Accordingly, the modelled muscle oxygen diffusion coefficient was not modified between any solvent conditions. Arterialized blood pH (7.35 ± .06 vs. 7.39 ± .04) and PaCO2 (34.1 ± 5.0 vs. 35.7 ± 4.3 mmHg) increased whilst PaO2 (81.8 ± 9.7 vs. 77.9 ± 10.6 mmHg) decreased. Discussion/Conclusion: The decrease in supine/standing HR associated with a general increase in HRV during recovery likely indicate an increase in parasympathetic modulation, which is compatible with the sedative effects of glycol ethers previously described in animal models. However, HR recovery was not altered. Despite no change in the O2 diffusion coefficient, there was an increase in PaCO2, a decrease in PaO2 and an increase in blood pH, all indicative of potential impaired blood oxygenation during exercise, to be further investigated. To conclude, exposition to different glycol ethers induced an enhanced parasympathetic activation without any changes in HR recovery or O2 diffusion.

Enhanced Optical and Thermal Properties of a Novel Yellow Quinophthalone Derivative for Color Filter Colorants in Image Sensors

Herein, the design and synthesis of novel yellow quinophthalone derivatives, 4,5,6,7‐tetrachloro‐2‐(6‐chloro‐2‐(3‐hydroxy‐1‐oxo‐1H‐cyclopenta[b]naphthalen‐2‐yl)quinolin‐4‐yl)isoindoline‐1,3‐dione (pC‐QP) and 4,5,6,7‐tetrachloro‐2‐(7‐chloro‐2‐(3‐hydroxy‐1‐oxo‐1H‐cyclopenta[b]naphthalen‐2‐yl)quinolin‐4‐yl)isoindoline‐1,3‐dione (mC‐QP), are used for use as yellow colorants in image sensors. The synthesized compounds are designed to modulate the optical properties based on the substituted positions of the chloride group within the quinophthalone structure. The solubility of pC‐QP and mC‐QP in propylene glycol monomethyl ether acetate solvent is found to be 0.08 and 0.15 wt%, respectively. The molar extinction coefficient values of pC‐QP and mC‐QP in solution are determined to be 3.14 × 104 and 3.62 × 105 L mol−1 cm−1, respectively. The transmittance of mC‐QP meets commercial requirements, exhibiting less than 0.3% between 412 and 475 nm and over 91% above 530 nm. Both pC‐QP and mC‐QP demonstrate high thermal stability with decomposition temperatures of 464 and 393 °C, respectively. As a result, mC‐QP emerges as an excellent candidate material for use as a yellow colorant in image sensors due to its outstanding properties.

Preparation of fluorine and silicon modified cationic acrylic resin and its application in cathodic electrodeposition coatings

Purpose Fluorinated silicon polymers are expected to be adopted in specific coatings to afford outstanding advantages, such as high chemical and photochemical resistance, low surface tension and low refractive index. The modified acrylate resin is prepared via solution polymerization of fluorine and silicon monomers, acrylate monomers and other functional monomers. The purpose of this paper is that the fluorine and silicon monomers such as vinyltriethoxysilane (VTES) and hexafluorobutyl methacrylate (HFMA) and some cheap monomers such as styrene are used to prepare the cationic acrylic resin. Design/methodology/approach The fluorine and silicon modified cationic acrylic resin is prepared via solution polymerization technology, which uses butyl acrylate (BA), methyl methacrylate (MMA), styrene (St), HFMA, VTES, dimethylaminoethyl methacrylate (DMAEMA) and hydroxypropyl methacrylate (HPMA) as the co-polymerized monomers, propylene glycol monomethyl ether (PGME) as solvent and 2,2-Azo-bis-iso-butyronitrile (AIBN) as the initiator to create a resin to introduce the Si–O and C–F into the polymer chains. The cathodic electrodeposition (CED) coatings were prepared by mixing the synthetic resin and blocked isocyanate. Findings The influence of the amounts of HFMA and VETS on the resin and the resultant CED coatings is investigated in detail. The optimum amounts of HFMA and VETS are obtained, which is 7–8% and 4–5%, respectively. The hydrophobicity and the acid and alkaline resistance of the film are improved when VETS and HFMA are introduced to co-polymerize with other monomers. Originality/value The fluorine and silicon monomers such as VTES and HFMA and some cheap monomers such as styrene, which are used to prepare the cationic acrylic resin, are seldom reported in the open literature.

Hematological variations in healthy participants exposed 2 h to propylene glycol ethers under controlled conditions

Glycol ethers are solvents used in a plethora of occupational and household products exposing the users to potential toxic effects. Several glycol ethers derived from ethylene glycol induce hematological toxicity, such as anemia in workers. The exposure effects on blood cells of glycol ethers derived from propylene glycol are unknown in humans. The aim of our study was to evaluate blood parameters indicative of red blood cell (RBC) hemolysis and oxidative stress in participants exposed to propylene glycol (propylene glycol monobutyl ether (PGBE) and propylene glycol monomethyl ether (PGME)), two extensively used propylene glycol derivatives worldwide.Seventeen participants were exposed 2 h in a control inhalation exposure chamber to low PGME (35 ppm) and PGBE (15 ppm) air concentrations. Blood was regularly collected before, during (15, 30, 60, and 120 min), and 60 min after exposure for RBC and oxidative stress analyses. Urine was also collected for clinical effects related to hemolysis.Under the study conditions, our results showed that the blood parameters such as RBCs, hemoglobin concentration, and white blood cells tended to increase in response to PGME and PGBE exposures. These results raise questions about the possible effects in people regularly exposed to higher concentrations, such as workers.

Novel Yellow Azo Pyridone Derivatives with Different Halide Atoms for Image-Sensor Color Filters.

Novel yellow azo pyridone dye derivatives were synthesized for use in image-sensor color filters. The synthesized compounds have a basic chemical structure composed of azo, hydroxy, amide, and nitrile groups as well as different halide groups. New materials were evaluated on the basis of their optical, thermal, and surface properties under conditions mimicking those of a commercial device fabrication process. A comparison of their related performance revealed that, among the four prepared compounds, 5-((4,6-dichlorocyclohexa-2,4-dien-1-yl)diazenyl)-6-hydroxy-1,4-dimethyl-2-oxo-1,2-dihydropyridine-3-carbonitrile (Cl-PAMOPC) exhibited the best performance as an image-sensor color filter material, including a solubility greater than 0.1 wt% in propylene glycol monomethyl ether acetate solvent, a high decomposition temperature of 263 °C, and stable color difference values of 4.93 and 3.88 after a thermal treatment and a solvent-resistance test, respectively. The results suggest that Cl-PAMOPC can be used as a green dye additive in an image-sensor colorant.

Facile and precise quantitative determination of silicon in naphtha by inductively coupled plasma-optical emission spectroscopy

The amount of silicon in naphtha must be controlled because it results in silica deposits in vehicle components, such as spark plugs, catalytic converters, and oxygen sensors, which can lead to fuel economy degradation, increased emissions, and damage to catalytic converters. Naphtha has low specific gravity and high volatility; plasma does not form during analysis using inductively coupled plasma-optical emission spectrometry. Therefore, the analysis of silicon in naphtha has been conducted using a dilution method with organic solvents. On the other hand, a high dilution factor increases the LOQ (limit of quantitation), making it difficult to analyse below 100 ppb. In this study, propylene glycol monomethyl ether acetate (PGMEA) was used to solve this problem because it has excellent naphtha solubility, low volatility, and is used widely in semiconductor processing. A LOQ and LOD (limit of detection) of up to 3.3 ppb and 1.0 ppb, respectively, could be achieved using a concentration method by diluting naphtha in PGMEA and heating it. In addition, the reference materials were prepared with octamethylcyclotetrasiloxane to ensure analysis accuracy; excellent results were obtained with an 88% recovery rate.

Influence of spin casting solvent on the self‐assembly of silicon‐containing block copolymer thin films via high temperature thermal treatment

AbstractThe present paper focuses on the influence of different solvents (toluene, mesitylene, acetone, tetrahydrofuran, propylene glycol monomethyl ether acetate (PGMEA) and ethyl acetate) on the self‐assembly behaviour of cylinder‐forming polystyrene‐block‐poly(dimethylsiloxane‐random‐vinylmethylsiloxane) diblock copolymer films deposited on thin brush layers of polystyrene (PS) or polymethylmethacrylate (PMMA) polymers grafted to a silicon substrate. The morphology and the key metrics for all samples were determined from the analysis of the SEM images and their evolution was investigated, as a function of the annealing time at 310 °C, for each solvent and for both PS and PMMA brushes. In general, shorter correlation lengths ξ are observed on PS brushes than on PMMA brushes. In addition, SEM data analysis reveals that tetrahydrofuran, PGMEA and ethyl acetate solvents promote a morphological change from fingerprint‐like parallel cylinders to a hexagonally packed dot pattern for annealing time tA > 30 s. Finally, the line edge roughness and linewidth roughness values are weakly dependent on both the casting solvent and the nature of the grafted brush. The reported data reveal that the choice of the polymer brush nature and of the solvent employed during the spin coating of the diblock copolymer film could substantially affect the self‐assembly process and requires accurate optimization due to their subtle interplay. © 2021 Society of Industrial Chemistry.

Investigating the Role of EPA and DHA on Cellular Oxidative Stress; Profiling Antidiabetic and Antihypertensive Potential.

Polyunsaturated fatty acids (PUFAs) remain part of the diet and are essential for growth and development. Furthermore, omega - 3 fatty acids boost various cardiovascular disease risk factors as well as lower blood pressure and cholesterol levels. The effects of PUFAs on glycemia in type 2 diabetes patients are unclear. In the present study, the anti-diabetic and anti-hypertensive potential of eicosapentenoic acid (EPA) and docosahexaenoic acid (DHA)-two polyunsaturated fatty acids-were examined. Using 3T3-L1 pre-adipocyte cells fed with PUFAs, the antioxidant capacity of EPA and DHA was assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay/test. The DPPH activity of EPA and DHA was 49.72 and 50.51%, respectively, indicating a reduction in oxidative stress. The number, size, and total lipid content of adipocytes in adipose tissue were used to study the anti-diabetic effect of EPA and DHA. Both PUFAs were revealed to have a much lower capacity for cell lysis of 3T3-L1 pre-adipocytes when compared to propylene glycol monomethyl ether acetate (PMA). In 3T3-L1 pre-adipocyte cells that had been treated with EPA and DHA, the gene expression profiles for ATP synthase 6 were examined. The results demonstrated a similar trend of reducing total lipid content in 3T3-L1 pre-adipocyte cells treated with EPA and DHA. The amount of cell lysis was then examined for 3T3-L1 pre-adipocyte cells exposed to DHA and EPA, and the results showed 38.45% and 41.26%, respectively. In the 3T3-L1 pre-adipocyte cells, treatment with PUFAs, EPA, and DHA dramatically lowered total lipid content after 48 hours. The study also revealed that exposing 3T3-L1 pre-adipocyte cells to EPA at 90 g/ml for 48 hours reduced the total lipid content by a significant amount. According to the findings, EPA and DHA therapy reversed oxidative stress in mitochondria and upregulated the ATP synthase 6 gene. This discovery shows how EPA and DHA have anti-diabetic and hypertension properties.

Blood absorption toxicokinetics of glycol ethers after inhalation: A human controlled study

Glycol ethers are organic solvents present in countless products for professional and domestic use. The main toxicological concerns are hematotoxicity, respiratory and reproductive toxicity. The general population can be exposed when using products containing one or several glycol ethers that evaporate or if sprayed, generate aerosols that can be inhaled. The rate at which glycol ethers enters blood following inhalation exposure are unknown in humans, and chemical risk assessors only rely on animal and in vitro toxicity studies. Propylene glycol monomethyl ether (PGME) and propylene glycol monobutyl ether (PGBE) are two examples of glycol ethers used worldwide. Our study aimed to provide human toxicokinetic data after inhalation exposure of low PGME and PGBE concentrations tested alone or in mixture. Healthy participants (n = 28) were exposed to 35 ppm (131 mg/m3) of PGME and 15 ppm (i.e., 83 mg/m3) of PGBE for 2 or 6 h. Blood was regularly collected during the exposure sessions. PGME and PGBE were immediately bioavailable in blood during exposure, and the mean absorption rates were up to 13 μg/L/min and 2.45 μg/L/min, respectively. Maximum mean blood concentration (Cmax) was 2.91 mg/L and 0.41 mg/L for PGME and PGBE. The cumulative internal doses over time (area under the curve, AUC) were 11 mg∗h/L and 1.81 mg∗h/L for PGME and PGBE. PGME and PGBE total blood uptake could possibly be higher in physically active individuals, such as workers. We recommend that glycol ethers present on the market undergo toxicological testing with the internal doses we found in our toxicokinetic study.

Pressure Swing-Based Reactive Distillation and Dividing Wall Column for Improving Manufacture of Propylene Glycol Monomethyl Ether Acetate

Propylene glycol monomethyl ether acetate (PGMEA) is a commonly used solvent in the rapidly developing semiconductor industry. Ultra-high purity PGMEA is required for this ultra-precision industry and to satisfy the current strict waste management regulations. The traditional PGMEA production process consumes considerable energy and has a high production cost. In this study, a novel heat integrated and intensified design, which applies a dividing wall column, reactive distillation, and pressure swing techniques, was proposed for improving the energy efficiency and reducing the cost of PGMEA production. Heat integration was applied to maximize the heat recovery of the process. All processes were simulated using the commercial simulator Aspen Plus V11. The economic and environmental parameters of the process alternative were assessed for a fair comparison with the conventional process. The results showed that heat integration of the optimal pressure swing-based reactive distillation and dividing wall column processes could reduce the energy requirement and TAC by 29.5%, and 20.8%, respectively, compared to that of the optimal conventional process. The improved design provides a strong basis for achieving more sustainable PGMEA production.

Highly efficient degradation of organic pollutant mixtures by a Fe(III)-based MOF-catalyzed Fenton-like process in subcritical water

Propylene glycol monomethyl ether acetate (PGMEA) photoresist solvent and monoaromatics are typical organic pollutants found in the wastewater discharged from semiconductor manufacturing processes. Conventional treatment technologies, however, remain mostly ineffective to eliminate these pollutants from aqueous streams. Herein, we developed a novel strategy for highly efficient degradation of PGMEA and archetypal monoaromatics (i.e., benzene, toluene, xylene, phenol, and cresol) in aqueous solution by heterogeneous Fenton-like process with a flexible Fe-MOF (MIL-88B) under mild subcritical water (SCW) condition (100 °C). The as-synthesized MIL-88B(Fe) microbipyramids possess large pore channels (∼32 nm) and open iron sites. The results showed that the SCW-mediated heterogeneous Fenton-like process at 100 °C with an optimal catalyst loading of 1 wt% exhibited a remarkable degradation performance toward target organic pollutants in a multicomponent system, affording a 92% total organic carbon (TOC) removal in 60 min. This mineralization efficiency was found to be notably superior to those of traditional homogeneous Fenton (FeSO4/H2O2; ∼54%) and Fenton-SCW (∼60%) processes. The practicability of this approach was demonstrated using real world water samples (i.e., river water, fishpond water, and wastewater) with >80% TOC removal efficiency. This study showed that the heterogeneous Fenton-like process utilizing an inexpensive, nontoxic, and reusable MIL-88B(Fe) MOF under mild SCW conditions is a promising strategy for treating semiconductor waste effluents and environmental water matrices containing toxic recalcitrant organics in an eco-friendly and efficient manner.

Apparent molar volumes of ILs [EmimNTf2], [BmimNTf2], and [BmmimNTf2] in DEC and PEGMME solvents

Different groups have important influence on the interaction between molecules. In order to understand the effect of group introduction on the molecular interaction in solution, the densities of six diluted solutions including three ionic liquids (ILs) and two organic solvents were measured. The groups include methylene and methyl. The three ILs are 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([Emim][NTf2]), 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([Bmim][NTf2]), and 1-butyl-2,3-dimethylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([Bmmim][NTf2]). The organic solvents are diethyl carbonate (DEC) and propylene glycol monomethyl ether (PEGMME). The measured densities were used to calculate apparent molar volumes, Vϕ/cm3·mol-1, from 293.15 to 328.15 K with ± 0.02 K. Then, the fitting of infinite dilution apparent molar volumes, Vϕ0/cm3·mol-1, were obtained by using the calculated values of apparent molar volumes. The effects of different structures of ILs cations and organic solvents on the apparent molar volume, infinite dilution apparent molar volume, limiting apparent molar expansibility and thermal expansibility coefficient were discussed.

Sustainable concept design including economic, environment and inherent safety criteria: Process intensification-reactive pressure swing distillation

In this paper, a systematic framework for concept design of sustainable chemical process is used to investigate process intensification-the reactive pressure swing process considering inherent safety, environment performance and economic performance comprehensively. The transesterification reaction between propylene glycol monomethyl ether and methyl acetate for propylene glycol monomethyl ether acetate production is used as case to accomplish this research. The total annual cost, the total greenhouse gases and two inherent indexes referred to process route index and process stream index are used to account for economic performance, environment performance and inherent safety of the overall route and individual parameter, respectively. Sensitivity analysis demonstrates reaction pressure swing as process intensification has strong interaction behavior and nonlinearity degree in term of economic performance. The inherent safety, environment performance and economic performance of reactive pressure swing distillation is evaluated and compared with conventional three-columns process. Compared with conventional process, the main contribution to inherent safety level is reduction of pressure factor in term of process route index for reaction pressure swing distillate process. The results illustrate the reaction pressure swing as process intensification can achieve sustainable chemical process with inherent safer, environmentally friendly and economic performance.

Influence of collection and storage materials on glycol ether concentrations in urine and blood

Glycol ethers, such as propylene glycol monomethyl ether (PGME) and propylene glycol monobuthyl ether (PGBE) are solvents found in many professional and domestic products. In biomonitoring studies, the type of materials used to collect, store, and transport these samples can greatly influence the analytical results because materials can adsorb the analyte. Plastic tubes generally have a hydrophobic internal surface that can reduce the concentration of certain chemicals and result in an underestimation of workers' exposures. The aim of this study was to assess whether the storage of PGME and PGBE spiked blood and urine samples led to different PGME and PGBE concentrations in vials made of glass and common plastics (polypropylene (PP), polyethylene (PE) or polystyrene (PS)). Glycol ether concentrations were quantified with headspace gas chromatography equipped with a flame ionization detector. Our results show stable urinary PGME and PGBE concentrations in PP, while up to 15% variations in urinary PGME for PE and PS. For PGME and PGBE in blood, we observed no statistically significant losses in glass, while losses were recorded for all types of plastic tested (PS, PP and PE). We conclude that biomonitoring samples should be collected in glass for blood and PP for urine.

Effect of surfactin on removal of semi-volatile organic compound: Emphasis on enhanced biofiltration performance

The performance of a lab-scale biotrickling filter (BTF) inoculated with a mixed fungal consortium was investigated for the simultaneous abatement of 2-ethylhexanol; a hydrophobic semi-volatile organic compound (SVOC), and propylene glycol monomethyl ether (PGME). The BTF performance was investigated in the presence of lipopeptide-type biosurfactant, surfactin. The effect of surfactin on the removal efficiency and elimination capacity was examined at stretched inlet loading rates (LR): 1.04 to 15.7 and 3.2–48 g m−3 h−1 of PGME and 2-ethylhexanol, respectively. Seeding the BTF with 50 mg L−1 of surfactin maintained high and consistent removal efficiencies of PGME and 2-ethylhexanol up to LRs of 15.7 and 32 g m−3 h−1, with removal efficiencies of 98.5 and 99%, respectively. Once the LR of 2-ethylhexanol increased to 48 g m−3 h−1, a substrate inhibition was observed, accompanied by a sudden decrease in removal efficiency from 99.2 to 62.3%. At the same LR, the BTF performance was improved by reseeding 100 mg L−1 of surfactin, hence, reinstated the removal efficiency of 2-ethylhexanol to 92.7% and achieving a maximum elimination capacity of 44.5 g m−3 h−1. This enhanced SVOC uptake rate was further confirmed by a considerable increase in reaction rate constant from 0.005 to 0.017 s−1. A batch study was also conducted at the end of the experimental run to better understand the correlation between surfactin concentrations and the time-dependent partition coefficient of 2-ethylhexanol. Biofilm microbial community structure revealed relative abundancy of 72 and 28% of Trichoderma asperellum and Fusarium solani, respectively. The findings of this study show for the first time that the removal of a semi-VOC such as 2-ethylhexanol is feasible in the presence of surfactin and hence improving the bioavailability of hydrophobic semi-VOC.

Comprehensive approach for reducing health risks due to indoor air pollutants

Individuals living in an indoor environment are typically exposed to a greater variety of air pollutants than in an outdoor environment. Numerous sources of chemical emissions are found in the indoor environment, depending on the building materials as well as the lifestyle of the occupants. The quality of the indoor environment considerably impacts public health. Japan has established Indoor Air Quality guidelines (IAQGs) for 13 chemicals, including formaldehyde, acetaldehyde, xylene, ethylbenzene, styrene, 1,4-dichlorobenzene, and toluene. However, the pollutant types and concentrations have been inconsistent over time because of altered lifestyles and the development of novel household products and building materials. Therefore, a comprehensive approach and action plan for the overall reduction of health risks because of indoor air pollutants are required for public health protection. To determine the high-risk indoor air pollutants that should be reduced, a preliminary risk assessment using data from nationwide exposure assessments and existing hazard data was conducted. As the result, 11 indoor air pollutants: 2-ethyl-1-hexanol, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, ethyl acetate, butyl acetate, propylene glycol monomethyl ether, 3-methoxy-3-methylbutanol, diethylene glycol methyl ether, diethylene glycol ethyl ether, propylene glycol monomethyl ether acetate, and methyl isobutyl ketone were identified. Subsequently, we reviewed the hazard or toxicological data for the 13 chemicals with established IAQGs and the 11 novel chemicals without established IAQGs to update their hazard assessments. The reference values for acute and chronic effects were determined from the reviewed information. The process and result of the preliminary risk assessment and the progress of the updated hazard assessments are reported.

Investigation of ink modification for aerosol jet printing process on FR-4 substrate

Non-contact, direct-write aerosol jet (AJ) printing technology using a variety of functional nanomaterial inks has been regarded as one of the most promising approaches for large-area additive manufacturing. The development and atomization of inks have a considerable effect on the printing quality. Therefore, in this study, the effect of a specific ratio of silver nanoparticle ink and a co-solvent of propylene glycol monomethyl ether (PGME) and ethylene glycol (EG) was investigated. The results indicated that the proportion of the solvent in the silver nanoparticle ink could affect the electrical characteristics of the printed lines. The prepared conductive ink with 95% silver nanoparticle ink and 5% co-solvent at a curing temperature of 180 °C demonstrated superior electrical conductivity and adhesion on the substrate.

Human skin permeation rates ex vivo following exposures to mixtures of glycol ethers

Skin exposure to cleaning products in the general and occupational population are a public health concern. Among the most frequently identified amphiphilic organic solvents in cleaning products are propylene glycol monomethyl ether (PGME) and propylene glycol n-butyl ether (PGBE). Internal dose from skin exposure may be efficiently evaluated using in vitro flow-through diffusion cells with excised human skin. Our aim in this study was two-fold; 1) characterize the permeation rates (J), time lag (Tlag), and permeation coefficients (Kp) of PGME and PGBE in human ex-vivo skin permeation assays, and 2) determine a possible mixture effect on skin permeation characteristics when applied together. Our results showed a short Tlag for PGME and was reduced further depending on the amount of PGBE in the mixture (Tlag was reduced from 2 h to 1–1.7 h) for fresh skin. PGBE Tlag slightly increased when mixed with 50 % or more PGME. Permeation rate decreased to half for both PGME and PGBE in mixture at any concentration. This substantial permeation was greater with previously frozen skin. This mixture effect could favor permeation of other compounds through human skin.

Electrochemical, Photophysical and Theoretical Studies of Novel Zinc Phthalocyanines.

In this research, we successfully synthesized three novel zinc phthalocyanines and applied for electrochemical and photo physical properties. These phthalocyanines are naphthoxy derivatives with methyl, benzyl and butyl-benzyl, with halo substitution (PCME, PCBN and PCBBN) and poses very good solubility in all industrial solvents. To check the preliminary results of LCD green color filter properties of these molecules, we taken the UV-Visible absorption and transmittance studies in Propylene glycol monomethyl ether acetate and achieved around 90% of transmittance in the region of 400-550 nm. Further understand the solubility of our phthalocyanines, we checked the aggregation property in PGMEA and we observed no any aggregation. All compounds showed very nice electro chemical properties with nice oxidation and reduction peaks. These phthalocyanines are fit for LCD color filter applications. Finally to get insights of the electronic and UV-Visible properties of the new dyes, the DFT calculations were performed.