Physical Evidence of Oil Uptake and Toxicity Assessment of Amphiphilic Grafted Nanoparticles Used as Oil Dispersants
1
Citation
40
Reference
10
Related Paper
Citation Trend
Abstract:
Herein, we report the toxicity evaluation of a new prototype dispersant system, silicon dioxide nanoparticles (NPs) functionalized with (3-glycidoxypropyl)triethoxysilane (GPS) and grafted poly(ε-caprolactone)-block-poly[oligo(ethylene glycol)methyl methacrylate mono-methyl ether] (NP-PCL-POEGMA). This serves as a follow up of our previous study where grafted silicon dioxide NPs functionalized with GPS and grafted hyperbranched poly(glycidol) (NP-HPG) were evaluated for reducing the toxicity in embryo, juvenile, and adult fish populations. In this study, the NP-HPG sample is used as a baseline to compare against the new NP-PCL-POEGMA samples. The relative size was established for three NP-PCL-POEGMA samples via cryogenic transmission electron microscopy. A quantitative mortality study determined that these NPs are non-toxic to embryo populations. An ethoxyresorufin-O-deethylase assay was performed on these NP-PCL-POEGMA samples to test for reduced cytochrome P450 1A after the embryos were exposed to the water-accommodated fraction of crude oil. Overall, these NP-PCL-POEGMA NPs better protected the embryo populations than the previous NP-HPG sample (using a protein activity end point), showing a trend in the right direction for prototype dispersants to replace the commercially utilized Corexit.Keywords:
Triethoxysilane
Abstract This paper evaluated dispersants for high densityinvert-emulsion drilling fluids weighted with manganese tetroxide (Mn3O4) particles for high temperature applications. Additionally, the use of dispersants to control the reaction of cleaning fluid with Mn3O4-based filter cake was studied. The dispersants selectedare non-toxic to aquatic organisms and biodegradable. Adding dispersants to the drilling fluid will result in reduced sag, rheological properties, and low fluid-loss. Three dispersants (A, B, and C)improved the flow behavior Oil-based drilling fluids weighted mainly with manganese tetraoxide particles. They are based on ethoxylated alcohol and polyether carboxylic acid. Dispersant A was anionic and dispersants B and C were non-ionic. In addition, three dispersants (D, E, and F) showed excellent results in controlling the reaction rate of cleaning fluids with manganese tetraoxide particles. Dispersant D was based on sulfonic acid, dispersant E was based on phosphate ester, and dispersant F was based on malic acid copolymer. Dispersant B showed improved the rheological/filtration properties and sag before/after heat aging at 400°F and 16 hours aging time for Mn3O4 oil-based drilling fluids (1.9 SG) than fluids with or without dispersants A or C. Combination of ionic and non-ionic dispersants improved the filtration properties of oil-based drilling fluids (2.1 SG) weighted mainly with manganese tetraoxide particles. Using dispersant E, the reaction rate of lactic acid/Mn3O4 system was the lowest, followed by dispersant F, and then dispersant D. Dispersants D, E, and F can be used as additives in the cleaning fluid formulation to control the reaction with Mn3O4-based filter cake.
Filtration (mathematics)
Cite
Citations (3)
Abstract In this study, a novel library of thermoresponsive homopolymers based on poly (ethylene glycol) (EG) (m)ethyl ether methacrylate monomers is presented. Twenty‐seven EG based homopolymers were synthesized and three parameters, the molar mass (MM), the number of the ethylene glycol groups in the monomer, and the chemistry of the functional side group were varied to investigate how these affect their thermoresponsive behavior. The targeted MMs of these polymers are varied from 2560, 5000, 8200 to 12,000 g mol −1 . Seven PEG‐based monomers were investigated: ethylene glycol methyl ether methacrylate (MEGMA), ethylene glycol ethyl ether methacrylate (EEGMA), di(ethylene glycol) methyl ether methacrylate (DEGMA), tri(ethylene glycol) methyl ether methacrylate (TEGMA), tri(ethylene glycol) ethyl ether methacrylate (TEGEMA), penta(ethylene glycol) methyl ether methacrylate (PEGMA), nona(ethylene glycol) methyl ether methacrylate (NEGMA). Homopolymers of 2‐(dimethylamino) ethyl methacrylate (DMAEMA) were also synthesized for comparison. The cloud points of these homopolymers were tested in different solvents and it was observed that it decreases as the number of EG group was decreased or the MM increased. Interestingly, the end functional group (methoxy or ethoxy) of the side group has an effect as well and is even more dominant than the number of EG groups.
Molar mass
Cite
Citations (48)
We investigated the effects of particle concentration and an additive amount of a dispersant on the adsorption behavior of dispersant. Ammonium polycarboxylate, one of the typical polyelectrolyte was used as a dispersant in this study. Alumina slurries were prepared by changing the concentrations of both the particle and dispersant and kept in a test tube for at least 2 d. After that, the adsorbed dispersant amount was calculated from the residual dispersant concentration measured by a total organic carbon analyzer. It was found that the adsorbed dispersant amount strongly depends on the additive dispersant amount on the basis of the unit mass of particles in the slurry regardless of the particle concentration. It was also shown that polycarboxylic acid strongly absorbs onto an alumina surface and can not be desorbed by dilution, suggesting that its adsorption behavior differs from physical adsorption.
Particle (ecology)
Dilution
Suspension
Cite
Citations (15)
Abstract Copolymers of methacrylaldehyde with hydrophilic monomers — 2‐hydroxyethyl methacrylate, 5‐hydroxy‐3‐oxapentyl methacrylate, 8‐hydroxy‐3,6‐dioxaoctyl methacrylate, N ‐ethylmethacrylamide, N , N ‐diethylacrylamide, and N , N ‐diethylmethacrylamide — were prepared by solution polymerization in N , N ‐dimethylformamide initiated with 2,2′‐azodiisobutyronitrile. In the copolymer of methacrylaldehyde (1) with 2‐hydroxyethyl methacrylate (2) ( r 1 = 0,77, r 2 = 0,36) and in the copolymer of methacrylaldehyde with N , N ‐diethylacrylamide ( r 1 = 3,79, r 2 = 0,14) the content of CHO groups corresponds to that ot methacrylaldehyde units in the triads comonomer — methacrylaldehyde — comonomer; in the copolymer of methacrylaldehyde with N ‐ethylmethacrylamide ( r 1 = 4,07, r 2 = 0,14) both comonomers react with each other and the content of CHO groups is very low, while in the copolymer of methacrylaldehyde with 5‐hydroxy‐3‐oxapentyl methacrylate ( r 1 = 1,48, r 2 = 0,34) the majority of methacrylaldehyde units contain an unreacted CHO group.
Comonomer
Dimethyl formamide
Cite
Citations (5)
Triethoxysilane
Cite
Citations (0)
Dispersion mechanisms of different dispersants were introduced briefly, and the aid-grinding, stable dsipersing, diluting and water reducing, and energy consumption reducing effects of the dispersant during the preparation of the ferrite were also discussed. The dispersive effect of four kins of dispersants in the ferrite slurry were investigated with a fixed content of 1% for the dispersants. The results showed that the dispersive effect of different dispersants is different. For the dispersant A with a better dispersive effect, the effect of its content on the dispersion was further investigated. The results indicated that an optinal amount of dispersant exists. Therefore, the proper dispersant and its content used for dispersing the ferrite slurry with different composition and prepared by different process should be determined by experiments.
Cite
Citations (0)
ABSTRACT Laboratory studies on dispersant effectiveness were conducted to assess the effects of several variables and to determine the action mechanisms of dispersants. The variables examined were temperature, salinity, and dispersant quantity. Dispersant effectiveness was measured as a function of the five oil bulk components: asphaltenes, aromatics, polar compounds, saturate compounds, and waxes. The effect of water temperature variation is logarithmically correlated with dispersant effectiveness. With regard to salinity, effectiveness is at a peak when salinity is about 40%c (parts per thousand) of typical commercial dispersant formulations and falls to nearly 0 as salinity decreases to 0. Effectiveness also falls to 0 as salinity rises from 40 to 80%o. This behavior is explained by the necessity for a certain level of ionic strength to stabilize the surfactant between the oil droplet and the water. Dispersant quantity was also found to be an important factor. Dispersant-to-oil ratios greater than about 1:40 or 1:60 result in very low dispersant effectiveness. Effectiveness is logarithmic with respect to dispersant-to-oil ratio. Dispersion experiments wee conducted to investigate the effects of oil composition. Dispersant effectiveness is positively and strongly correlated with the saturate concentration in the oil and is negatively correlated with aromatic, asphaltene, and polar compound contents of the oil. Dispersant effectiveness is only weakly correlated with oil viscosity. Dispersant effectiveness is primarily limited by oil composition.
Asphaltene
Cite
Citations (27)
Abstract Copolymers of tri‐n‐butyltin‐α‐chloroacrylate (TCA) with 2‐hydroxyethyl methacrylate (HEMA) and 2‐hydroxypropyl methacrylate (HPMA) were synthesized in solution at 55°C using azobisisobutyronitrile as initiator. Copolymer compositions were determined by tin analysis. Monomer reactivity ratios were calculated by the Kelen‐Tüdős method. The copolymers were further characterized by IR, 1 H‐NMR, TGA, DSC, XRD and solubility. Biotoxicity studies of the copolymers are also reported. The copolymer system is compared with similar copolymers of tri‐n‐butyltín methacrylate.
Azobisisobutyronitrile
Reactivity
Cite
Citations (0)
ABSTRACT This study evaluated the effectiveness of three dispersants in simulated seawater on five different fuel oils (both intermediate fuel oils (IFOs) and heavy fuel oils (HFOs)) with viscosities ranging from 1,079 to 6,615 cSt and densities ranging from 0.995 to 0.998 g/cc. The three dispersants were COREXIT® 9500 dispersant, a dispersant under development by ExxonMobil – ED-6™ gel dispersant, and FINASOL™ OSR 52 dispersant. Testing was done at two dispersant-to-oil ratios (DOR) – 1:20 and 1:10. All three dispersants were effective (70%+ dispersant effectiveness (DE)) for fuel oils with a viscosity less than 2,000 cSt - IFOs 180 and 380. The dispersants were less effective (16 to 58% DE) for the higher viscosity oils (ranging in viscosity from 4,258 to 6,615 cSt). Increasing the amount of dispersant from a DOR of 1:20 to 1:10 significantly improved DE. For example, the DE of the two HFOs studied increased from less than 42% to greater than 56% using COREXIT 9500™ dispersant. The results of our bench-scale study indicate that dispersants can disperse heavy fuel oils and, therefore, could be a response option for spills of these products in a marine environment.
Cite
Citations (0)