Abstract  The oxygenated additives propylene glycol methyl ether (PGME), propylene glycol ethyl ether (PGEE), dipropylene glycol methyl ether (DPGME) were studied to determine their influence on both the base diesel fuel properties and the exhaust emissions from a diesel engine (CO, NOx, unburnt hydrocarbons and smoke). For diesel blends with low oxygen content (<= 4.0 wt.%), the addition of these compounds to base diesel fuel decreases aromatic content, kinematic viscosity, cold filter plugging point and Conradson carbon residue. Also, each compound modifies the distillation curve at temperatures below the corresponding oxygenated compound boiling point, the distillate percentage being increased. The blend cetane number depends on the type of propylene glycol ether added, its molecular weight, and the oxygen content of the fuel. The addition of PGME decreased slightly diesel fuel cetane number, while PGEE and DPGME increased it. Base diesel fuel-propylene glycol ether blends with 1.0 and 2.5 wt.% oxygen contents were used in order to determine the performance of the diesel engine and its emissions at both full and medium loads and different engine speeds (1000, 2500 and 4000 rpm). In general, at full load and in comparison with base diesel fuel, the blends show a slight reduction of oxygen-free specific fuel consumption. CO emissions are reduced appreciably for 2.5 wt.% of oxygen blends, mainly for PGEE and DPGME. NOx emissions are reduced slightly, but not the smoke. Unburnt hydrocarbon emissions decrease at 1000 and 2500 rpm, but not at 4000 rpm. At medium load, the effect of the additives is much less significant, due to the fact that the ratio oxygen from additive/oxygen from air is much lower. (C) 2013 Elsevier Ltd. All rights reserved.

Abstract  We carried out the decomposition reaction of a polyol [poly(propylene glycol), PPG] in supercritical water (380-430 degreesC, 10-90 min) to understand the reactivity of polyols at high temperature and pressure. The main products, hydroxyacetone and diols (propylene glycol, dipropylene glycol and tripropylene glycol), were identified and characterized by mass spectrometry (GC/MS). The yield of hydroxyacetone was 33.0 wt.% at 430 degreesC for 10 min and the total yield of hydroxyacetone and diols was 56.7 wt.% at 380 degreesC for 60 min. The effect of reaction conditions (temperature, time and pressure) on yields was examined. The investigation of PPG decomposition pathway demonstrated that hydroxyacetone was the end product and resulted from propylene glycol only. (C) 2003 Elsevier Science Ltd. All rights reserved.

Abstract  RPSL-01 type photosensitive resin for Stereo lithography was prepared with 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate (UVR 6110), bisphenol A type epoxy diacrylate (EA-612), tripropylene glycol diacrylate (TPGDA), pentaerythritol triacrylate(PETA), triethylene glycol divinyl ether (DVE-3), benzil dimethyl ketal (Irgacure651) and a mixture of triarylsulfonium hexafluoroantimonate salts (UVI-6976) as raw materials. Some properties of the photosensitive resin were investigated. The viscosity of the photosensitive resin at 30 degrees C was 425mP(a).S, The glass transition temperature (Tg) of the UV-cured specimen was 47 degrees C, and the weight loss of the UV-cured specimen at 200 degrees C was less than 5%. The photosensitive resin and its UV-cured specimen were also characterized by infrared (IR).

Abstract  A new set of molar heat capacity data for aqueous {2-amino-2-hydroxymethyl-1,3-propanediol (TRIS) + glycol} at (30 to 80)degrees C and different concentrations (4% to 16% by weight TRIS or 56% to 44% by weight water, in a fixed amount of glycol - 40% by weight) were gathered via reliable measurement method and are presented in this report. The glycols considered were diethylene glycol (DEG), triethylene glycol (TEG), tetraethylene glycol (T(4)EG), propylene glycol (PG), dipropylene glycol (DPG), and tripropylene glycol (TPG). The 198 data points gathered fit the equation, C-p = C-p,C-a + B(1)m + B(2)m(2) + B(3)m(3), where C-p and C-p,C-a are the molar heat capacities of the (TRIS + glycol + water) and (water + glycol) systems, respectively, B-i the temperature-dependent parameters, and m the mole TRIS per kilogram (glycol + water). The overall average absolute deviation (AAD) of the experimental data from the corresponding values calculated from the correlation equation was 0.07%. (C) 2012 Elsevier Ltd. All rights reserved.

Abstract  Composites based on unsaturated polyester (UPe) resins and fumed silica AEROSIL (R) RY 50, NY 50, RX 50 and NAX 50, as well as graphite, TiO2 or organically modified clay CLOISITE 30B were prepared in order to investigate the influence of reinforcing agents on the mechanical properties of composites. Unsaturated polyester resins were synthesized from maleic anhydride and products of glycolysis, obtained by depolymerization of poly(ethylene terephthalate) with dipropylene glycol (UPe1 resin) and triethylene glycol (UPe2 resin) in the presence of tetrabutyl titanate catalyst. The obtained unsaturated polyesters were characterized by FTIR spectroscopy, acid and hydroxyl values, and their mechanical properties were also examined. Significant increase of the tensile modulus, tensile strength and decrease of the elongation at break was observed for composites prepared after addition of 10 wt.% of graphite or 10 wt.% of TiO2 to the UPe resins, indicating strong interaction between matrix and filler particles. On the other hand, nanocomposites prepared using UPe2 and hydrophobically modified silica nanoparticles showed lower tensile strength and tensile modulus than polymer matrix. The presence of CLOISITE 30B had no significant influence on the mechanical properties of UPe1, while tensile strength and tensile modulus of UPe2 increased after adding 10 wt.% of clay.

Abstract  The triethylene glycol and tripropylene glycol derivatives terminated with the CO2-philic phosphoryl groups, named 2-(2-(2-((2-ethylhexoxy(methoxy)phosphoryl)oxy)-ethoxy)ethoxy)ethyl 2-ethylhexyl methyl phosphate (EG3EH) and 2-(2-(2-((2-ethylhexoxy(methoxy)phosphoryl)oxy)propoxy)-propoxy)propyl 2-ethylhexyl methyl phosphate (PG3EH), were synthesized and characterized. The solubilities of EG3EH and PG3EH in scCO(2) were determined by a static method at temperatures from (313 to 333) K and over a pressure range of (10 to 19) MPa. The values calculated by the Bartle semiempirical model exhibited good agreement with the experimental data.

Abstract  Purpose - The purpose of this paper is to synthesise environment friendly UV curable polyurethane acrylate resins for various industrial applications and study the performance properties of the cured coating films applied over metal surfaces.

Design/methodology/approach - The polyurethane acrylate resin was synthesised using polyester polyol (synthesised using ethylene glycol, adipic acid and 1,6 hexane diol), isophorone diisocynate (IPDI) and 2-hydroxy ethyl methacrylate (HEMA). The different formulations were developed using various reactive diluents viz. monofunctional, difunctional, trifunctional and tetrafunctional (ethoxylated phenol monoacrylate, 1, 6 hexane diol di acrylate, dipropylene glycol di acrylate, trimethylol propane triacrylate, propoxylated trimethylol propane triacrylate, pentaerythrol triacrylate - PETA). These samples were cured under UV radiation. For effective curing, various compositions of oligomers, photoinitiator and reactive diluents were used. The mechanical, optical, rheological, chemical and stain resistance properties were evaluated.

Findings - The designed polyurethane acrylate gave good performance properties when used with reactive diluents having different functionality in different ratios for application over metal surfaces as protective coatings for various industrial applications. While using reactive diluents, the coating compositions showed significant enhancement of mechanical, physical and chemical resistance properties. Owing to different functionality of reactive diluents used, highly cross-linked structures are formed, which lead to excellent mechanical and chemical properties. The optimum results were obtained with PETA as reactive diluent.

Research limitations/implications - The polyurethane resin has been synthesised from polyester polyol (made up of ethylene glycol, adipic acid and 1, 6 hexane diol), IPDI, 2-HEMA. Besides, this, it can be synthesised from some other polyester polyol or polyether polyol. In addition to this, some other isocyanates such as TDI, MDI, HDI, HMDI, etc. may be used.

Practical implications - The study has provided a better solution for developing low volatile organic compound (VOC) products by using UV radiations, which can be cured within a minimum period of time and can save significant application curing time for the end-users. The developed product is also an environmentally friendly product.

Originality/value - Metallic surfaces are widely used in packaging industry in rigid and semi-rigid forms. One of the prime requirements of the surface is an attractive printing on it. Conventionally used coating system on metallic surfaces are not holding or retaining their decorative effect/gloss level to a large extent. For this purpose, an overprint varnish is normally used which is mostly solvent based. This paper has been able to suggest very good formulations for printing of metallic surfaces for packaging and for overprinting in particular, which is radiation curable and environment friendly.

Abstract  Twelve blend samples were prepared by physical mixing of epoxy acrylate resins with various monomers viz. ethoxylated phenol monoacrylate (EOPA), tripropylene glycol diacrylate (TPGDA) and trimethylol propane tri acrylate(TMPTA), having weight ratio of epoxy acrylate resin and monomers are 50:50, 60:40, 70:30, 80:20. These samples were cured under UV radiation using 5% photo initiator by weight. These blends were evaluated for mechanical, chemical & thermal properties. It was found that the sample having mono & tri functional monomers shows better properties than the samples having di functional monomer.

Abstract  A selective, sensitive, rapid and reliable method based on molecularly imprinted polymers (MIPs) with dual templates to determine total content of parabens in cosmetics was developed. With methylparaben (MP) and propylparaben (PP) as dual-templates, methacrylic acid (MAA) as a functional monomer and tripropylene glycol diacrylate (TPGDA) as a cross-linker, MIPs film on a glassy carbon electrode was constructed as paraben sensor. At oxidation potential of 0.94 V (vs. SCE), the peak currents on the MIPs sensor were proportional to the concentration of parabens with square wave voltammetry. As the ratio of MP to PP in the MIPs was 1:1.25, the regression equations for four parabens were almost the same. The linear range was 20-100 microM for MP and EP, 5-100 microM for PP, and 5-80 microM for BP, with detection limit of 0.4 microM for MP and EP, 0.2 microM for the others. The total content of parabens could be calculated according to the average of these four regress equations. At least 10 times of structural analogs, such as p-hydroxybenzoic acid, p-aminobenzoic acid and phenol would not interfere with the determination of parabens. Nonanalogous coexistences such as vitamin C had no response on the sensor at all. Rapid response of the MIPs sensor was obtained within 1 min. MIPs sensor had been used to determine total content of parabens in cosmetic samples with recoveries between 98.7% and 101.8%. It reveals that the MIPs sensor with multi-templates has a potential to determine the total content of a group of homologous compounds.

Abstract  Azobenzene ligands were uniformly anchored to the pore surfaces of nanoporous silica particles with single crystal NaCl using 4-(3-triethoxysilylpropylureido) azobenzene (TSUA). The functionalization delayed the release of NaCl significantly. The modified particles demonstrated a photocontrolled release by trans/cis isomerization of azobenzene moieties. The addition of amphiphilic solvents, propylene glycol (PG), propylene glycol propyl ether (PGPE), and dipropylene glycol propyl ether (DPGPE) delayed the release in water, although the wetting behavior was improved and the delay is the most for the block molecules with the longest carbon chain. The speedup by UV irradiation suggests a strong dependence of diffusion on the switchable pore size. TGA, XRD, FTIR, and NMR techniques were used to characterize the structures.

Abstract  The degradation of plasticizers by the yeast Rhodotorula rubra J-96-1 (American Type Culture Collection 9449) in the presence of glucose was studied. The plasticizers included the commonly used bis-2-ethylhexyl adipate (B(EH)A), dioctyl phthalate (DOP), and dioctyl terephthalate (DOTP), and the less commonly used dipropylene glycol dibenzoate (D(PG)DB) and diethylene glycol dibenzoate (D(EG)DB). The proposal had been made that the latter two plasticizers be used as alternatives to the first three, which have been associated with negative environmental impacts. The degradation of D(PG)DB or D(EG)DB led to a significant increase in solution toxicity, which was associated with the production of metabolites resulting from the incomplete breakdown of the plasticizers. The toxic metabolites in the D(PG)DB system were identified as isomers of dipropylene glycol monobenzoate. A pathway for the formation of this metabolite was proposed. The metabolite observed when D(EG)DB was being degraded was tentatively identified as diethylene glycol monobenzoate by analogy to the D(PG)DB system. In contrast, no metabolites were observable and toxicity did not increase in the media during the degradation of B(EH)A, DOP, or DOTP by R. rubra. Collectively, these results do not support the use of D(PG)DB and D(EG)DB as environmentally safe alternatives to B(EH)A, DOP, or DOTP.

Abstract  Wood plastic composite (WPC) formation was studied with simul wood and butylmethacrylate (BMA) at different compositions with swelling solvent methanol in the presence of a set of multifunctional acrylate monomer additives like N-vinyl Pyrrolidone (NVP), tripropylene glycol diacrylate (TPGDA) and trimethylol propane triacrylate (TMPTA) at a different doses between 1 and 3 Mrad using Co-60 gamma source. This was further investigated using another set of additives chosen from oligomers such as epoxy acrylate (EA), urethane acrylate (UA) and polyester acrylate (PEA). TMPTA yielded the highest polymer loading at relatively low dose (2 Mrad). Effect of co-additives like sulfuric acid (H+ ions), copper sulphate (Cu2+ ions) and urea was investigated in these series. Tensile strength (TS) of the composites were determined and the highest TS values were obtained with the composite produced in presence of urea.

Abstract  Wood plastic composites arc prepared under radiation of Co-60 gamma source with simul, a low grade wood of Bangladesh using a water soluble monomer acrylamide (AM) mixed with a swelling solvent methanol, water or methanol water (1:1) at different compositions in the presence of a number of additives and co-additives such as NVP (N-vinylpyrrolidone), TPGDA (tripropylene glycol diacrylate), TMPTA (trimethylol propane triacrylate), sulfuric acid. urea and copper sulfate. Polymer loading (PL) and tensile strength (TS) of the composites are measured. The role of these additives on the composites is also discussed. It is observed that nitrogen-atom containing-materials like urea, NVP and AM produce composites with the highest mechanical strength, and incorporation of copper into this system provides additional property of protection and preservation of the composites against attacks by insects and microbes.

Abstract  The development of flexible electronics requires the patterning of conductive and active semiconductor films. Although inorganic materials such as indium tin oxide and metal nanoparticles have high conductivity and transparency, their poor interfacial adhesion with organic layers, lack of flexibility, high weight and high capital costs are drawbacks. In contrast, organic conducting polymers have great potential for use in commercial flexible electronic applications because of their low production costs, environmental stability and acceptable conductivities. A UV-curable photoresist containing hydroxyl groups was prepared from a mixture of a photoinitiator, epoxy-acrylate resin, hydroxyethyl methacrylate and tripropylene glycol diacrylate. Patterns having line widths/spaces of 100/100 mu m and 10/5 mu m were fabricated on a poly(ethylene terephthalate) (PET) substrate using lithography techniques. (3-Methyl-3,4-dihydro-2H-thieno[3,4-]dioxepin-3-yl)methanol (ProDOT-OH) was self-synthesized through urethane linkages onto the surface of the patterned photoresist on the PET film, which was then dipped into a solution of another monomer, 3-thienylethoxybutanesulfonate (TEBS), and initiator and polymerized in situ to form conductive poly(ProDOT-OH-co-TEBS) films covering the surface of the patterned resist. The optimal conductivity of the poly(ProDOT-OH-co-TEBS) films was ca 905 cm(-1) with an optical transparency of ca 70%. A new bottom-up technique has been developed for the preparation of patterned organic transparent conductive films: self-synthesis of the monomer using urethane-forming reactions and subsequent in situ polymerization. The conductivity of the films can be controlled by the polymerization reaction time and the resolution of the pattern. These conductive patterned films might be applicable to the manufacture of industrial touch panels or chemical/biological sensors. (C) 2009 Society of Chemical Industry

Abstract  Speeds of sound have been measured in dipropylene glycol monobutyl ether + methanol, 1-propanol, 1-pentanol, 1-heptanol, across the entire composition range, at the temperature 298.15 K and atmospheric pressure. The speed of sound values were combined with excess molar volume to obtain values for the product K-s,K-m of the molar volume and the isentropic compressibility kappa(s), and the corresponding quantities K-s,(E)(m) were also calculated. The K-S(E),m values are negative for all mixtures. The deviation of the speeds of sound u(D) from their values u(id) in ideal mixtures were obtained for all measured mole fractions. These values are compared with mixing function deltau. The behaviour of u, deltau, u(D), and K-S(E),m as a function of composition and number of carbon atoms in the alcohol molecule is discussed.

Abstract  Excess molar volumes (V-m(E)) and viscosities (eta) have been measured as a function of composition for binary liquid mixtures of dipropylene glycol monomethyl ether and of dipropylene glycol monobutyl ether with 1-propanol and 2-propanol at 298.15 K and atmospheric pressure. The V-m(E) values for each of the mixture studied are negative over the whole composition range. The V-m(E) results have been used to estimate the partial molar volumes of the components at infinite dilution. From the experimental data, the deviation in eta from Sigmax(i)lneta(i) have been calculated. The results are discussed as a basis to understand some of the molecular interactions present in the mixtures. The viscosity data have been correlated with the equations of McAllister, Heric, and Auslaender.

Abstract  Acute effects during controlled exposure to some of the volatile organic compounds emitted from water-based paints were evaluated.

Healthy volunteers (10 atopics, 10 nonatopics, and 10 painters) were exposed to a mixture of propyleneglycol, texanol, diethyleneglycol monoethylether, diethyleneglycol monobutyl ether, and dipropyleneglycol monomethyl ether at a total concentration of 35 mg/m3 (G), a mixture of G and ammonia (15 mg/m3) (GA), and clean air (C).

Subjective ratings of irritation in eyes, nose, throat, and dyspnea were significantly higher during the G and GA conditions, when compared with during the C condition. Nasal mucosal swelling was observed after G but not after GA exposure. No effects of the exposure on the pulmonary function, markers of inflammation in nasal lavages, and renal function in urine were seen.

Exposure to G and GA caused mild irritation in eyes, nose, and airways.

Abstract  Ionic liquids are innovative media for applications, which offer large advantages over common chemicals, such a negligible vapor pressure, and thus, no air pollution potential, and comparative thermal stability. All these properties make them good solvents compared to the classical volatile chemicals and allow for their employment in reactions, extractions, and material processing. For this reason investigations into phase equilibria in many systems with ionic liquids are essential. This paper focuses on the liquid liquid equilibria of twenty binary mixtures composed of the imidazolium based ionic liquids with dicyanamide ([C(n)mim][DCA]) or bistriflamide([C(n)mim][NTf(2)])anions and glycols, or glycerol, or butan-1-ol. In this study, the following glycols were tested: (ethylene glycol (ethane-1,2-diol); propylene glycol (propane-1,2-diol); propane-1,3-diol; butylene glycols (butane-1,2-diol; butane-1,3-diol, butane-1,4-diol; butane-2,3-diol); diethylene glycol (2,2'-oxydiethanol); dipropylene glycol (4-oxaheptane-1,7-diol). The systems containing hydrophilic dicyanamide ionic liquid exhibit complete miscibility with the studied polyhydroxy alcohols. Solutions containing bis(trifluoromethylsulfonyl)amide ionic liquids demonstrate limited solubility with the investigated butane-1,2-diol and its isomers. It was found that miscibility of [C(n)mim][NTf(2)] with butanediols depends on the choice of the cation and the arrangement of hydroxyl groups in the alcohol structure.

Abstract  New coatings have been developed that display resistance to the nucleation and adhesion of ice [Simendinger, WH III, Miller, SD, Anti-icing composition. US Patent #6,702,953 2004]. These coatings contain a titanium alkoxide-based sol-gel system designed to facilitate the slow release of tripropylene glycol (TPG) and glycerol, which depress the freezing point of water. The performance and the lifetime of this coating critically depend on the rate at which TPG and glycerol are released to the coating surface. The kinetics and mechanism of this process are studied in this article. Mass loss measurements are reported for temperatures ranging from 22 to 90 degrees C for both the isolated sol-gel and the coating. Two regions of mass loss are observed: loss of isopropyl alcohol, which begins immediately after the reactants are mixed, and loss of TPG and glycerol, which begins at a later time, extending up to several months at low temperatures. Diffusivities and activation energies for IPA and TPG/ glycerol in the sol-gel are obtained from 22 to 90 degrees C and compared to similar data obtained for an anti-icing coating containing the dispersed sol-gel. The effect of changing the sol-gel reaction conditions on mass loss kinetics is also reported.

Abstract  Injectable and settable bone grafts offer significant advantages over pre-formed implants due to their ability to be administered using minimally invasive techniques and to conform to the shape of the defect. However, injectable biomaterials present biocompatibility challenges due to the potential toxicity and ultimate fate of reactive components that are not incorporated in the final cured product. In this study the effects of stoichiometry and triethylenediamine (TEDA) catalyst concentration on the reactivity, injectability, and biocompatibility of two component lysine-derived polyurethane (PUR) biocomposites were investigated. Rate constants were measured for the reactions of water (a blowing agent resulting in the generation of pores), polyester triol, dipropylene glycol (DPG), and allograft bone particles with the isocyanate-terminated prepolymer using an in situ attenuated total reflection Fourier transform infrared spectroscopy technique. Based on the measured rate constants, a kinetic model predicting the conversion of each component with time was developed. Despite the fact that TEDA is a well-known urethane gelling catalyst, it was found to preferentially catalyze the blowing reaction with water relative to the gelling reactions by a ratio >17:1. Thus the kinetic model predicted that the prepolymer and water proceeded to full conversion, while the conversions of polyester triol and DPG were <70% after 24h, which was consistent with leaching experiments showing that only non-cytotoxic polyester triol and DPG were released from the reactive PUR at early time points. The PUR biocomposite supported cellular infiltration and remodeling in femoral condyle defects in rabbits at 8weeks, and there was no evidence of an adverse inflammatory response induced by unreacted components from the biocomposite or degradation products from the cured polymer. Taken together, these data underscore the utility of the kinetic model in predicting the biocompatibility of reactive biomaterials.

Abstract  A systematic stoichiometric and kinetic model was developed for the acid-catalysed polyesterification of unsaturated dicarboxylic acids and mixtures of dicarboxylic acids. The model was based on a rigorous treatment of the functional groups and their reactions: esterification, cis-trans isomerization and double-bond saturation through Ordelt reaction. The model was applied on the polyesterification of maleic and phthalic acids with ethylene glycol, propylene glycol, diethylene glycol and dipropylene glycol in a semi-batch reactor at 160-195 degreesC. Kinetic and thermodynamic parameters included in the model were estimated with non-linear regression. It was found that important simplifications can be introduced: the rate constants of the different esterification and isomerization reactions can be set equal, whereas it was necessary to treat the different double-bond saturation reactions with individual rate constants. A comparison of model predictions with experimental data revealed that the proposed kinetic treatment is relevant for polyesterification of complex mixtures. (C) 2001 Elsevier Science Ltd. All rights reserved.

Abstract  Plastisol coatings based on starch and poly(vinyl alcohol) were investigated. Dry powders based on two different ratios of these two water-soluble polymers were prepared by spray drying aqueous polymer solutions. An oxidized and hydroxypropylated potato starch and a poly(vinyl alcohol) grade with a degree of hydrolysis of 72.5% were used. Poly(alkyl methacrylate) was used in order to improve the water vapour barrier of the coated materials. Starch-containing plastisol pastes were produced by two different rout'es: (1) by adding a liquid plasticizer (glycerol or poly(ethylene glycol)) to the starch/poly(vinyl alcohol)-based powder and (2) by mixing the dry starch/poly(vinyl alcohol)-based powder with the dry poly(alkyl methacrylate) powder and subsequently adding a mixture of liquid plasticizers (glycerol and dipropylene glycol benzoate) to the powder mixture. Free plastisol films and coated papers were produced. Two different base-papers were investigated; greaseproof paper and paperboard. It was possible to produce pure starch/poly(vinyl alchohol) plastisol coatings as well as plastisol coatings based on a mixture of incompatible polymers. Stratified structures created by a double layer coating operation were also investigated. In the case of the double coatings, the first plastisol layer was a pure starch/poly(vinyl alcohol) plastisol according to route 1 and the second layer was a pure poly(alkyl methacrylate) plastisol. The plastisol coatings resulted in improvements in the water vapour and oxygen barrier properties.

Abstract  Microemulsification is one of the novel techniques to reduce viscosity of vegetable oils to avoid durability problems in diesel engines. Microemulsion biofuels are transparent, thermodynamically stable, and single-phase mixtures of vegetable oils and ethanol in the presence of surfactants and co-surfactants. Additives have also been included in microemulsion biofuel formulations to improve their stability and fuel properties; however, there is limited research on the effect of additives on emission characteristics of microemulsion biofuels. In this study, microemulsion biofuels were formulated from palm oil/diesel blend (1:1 v/v), ethanol, surfactant, and co-surfactants. Five additives, ethylene glycol butyl ether (EGBE), diethylene glycol ethyl ether (DEGEE), propylene glycol ethyl ether (PGEE), dipropylene glycol methyl ether (DPGME), and ethyl acetate (EA), were used to study the effect of additives on phase behaviors, fuel properties, and emission characteristics. The results showed that studied additives could improve some fuel properties of microemulsion biofuels with negligible effect on phase stability. Additionally, it was found that carbon monoxide (CO) emissions from microemulsion biofuels with DEGEE and EA, and nitrogen oxide (NOx) emissions from microemulsion biofuels with all additives were lower than those from diesel and biodiesel. Therefore, DEGEE and EA can be considered as promising additives for microemulsion biofuel formulations, which can improve fuel properties as well as can significantly reduce CO and NOx emissions below the levels of diesel and biodiesel. These encouraging results offer options of additives for biofuel applications.

Abstract  HYPOTHESIS: The behavior/properties of micellar solutions are governed by Coulombic interactions that are influenced by the polarity of the surfactant head groups, hydrophobic tails, and solvent molecules. The addition of co-solvent should have a direct impact on solvent polarity and the size of the micelles are expected to decrease accordingly.

EXPERIMENTS: In this study, a mixed surfactant system is studied composed of a common anionic surfactant, sodium laureth sulfate-1, modified by a zwitterionic surfactant, cocamidopropyl betaine in deuterated water. In this system, worm-like micelles (WLMs) are formed. The influence of a co-solvent, dipropylene glycol (DPG) in the present of high salt content, is investigated. DPG primarily modifies the dielectric constant of the solvent.

FINDINGS: It was found that the addition of DPG slightly decreased the micelle radius, but dramatically reduced the persistence length as well as the contour length of the micelles. The relative dependence of contour length on salt concentration is not significantly changed. Thus, it is shown that the self-assembled structure can be tuned by adjusting solvent polarity without affecting the relative tunability of the WLM/ellipsoidal structure through counter ion concentration.

Abstract  In order to enhance electron-donating ability and absorptivity in the visible region of the spectrum, four novel organic dyes (CPC, TPC, CPN and TPN) with carbazole-phenothiazine or triphenylamine-phenothiazine as double electron donors (D), and cyanoacrylic acid or an aldehyde group as the electron acceptor (A) have been designed and synthesized. The dyes exhibit charge transfer properties in the ground and excited states and absorb strongly in the spectral range of 380-550 nm. Upon exposure to irradiation of a laser diode at 455 and 532 nm, the dyes together with an iodonium salt induced high polymerization efficiency in the cationic polymerization of bisphenol-A epoxy resin A (DGEBA) and free radical polymerization of tripropylene glycol diacrylate (TPGDA). An electron-transfer photosensitization mechanism was established based on steady-state photolysis experiments, theoretical calculations of molecular orbitals, and electrochemical analysis. Our results showed that these dyes would have extensive application in photopolymerization promoted by soft visible light.