Effect of Polyisobutylene Succinimide on the Physical Stability of an Environmentally Friendly Pesticide Oil Dispersion Suspension

Oil dispersible suspension concentrates are safe,green,and environmentally friendly formulations.Problems such as layering,pasting,and bottoming are frequently encountered during the production,storage,and transportation process.Polyisobutylene succinimide functions as a dispersant and exhibits great potential to improve the physical stability of the oil dispersible suspension concentrate.From a microscopic perspective,the sorption characteristics of the polyisobutylene succinimide dispersant T151 on penoxsulam particle surfaces were comprehensively evaluated with XPS,FTIR,and SEM.The T151 adsorption procedure complied with a pseudo-second-order kinetic adsorption model,and it was a kind of physical sorption with an Ea of 22.57 kJ⋅mol^(−1).The T151 sorption model was consistent with the Langmuir isotherm.The adsorption process was spontaneous and followed by an entropy increase.TheΔH^(θ)of dispersant T151 on the surface of penoxsulam particles was 31.59 kJ⋅mol^(−1).The adsorption procedure was endothermic,and the primary force was hydrogen bonding.The XPS results showed that the F and S electronic peaks at the penoxsulam interface decreased,and that the C electronic peak increased significantly after the adsorption of dispersant T151,indicating the adsorption on the surface of penoxsulam particles.The results of this study provide a vital theoretical basis for the application of polyisobutylene succinimide dispersants in oil dispersible suspension systems.

Direct hydrocarbon identification in shale oil reservoirs using fluid dispersion attribute based on an extended frequency-dependent seismic inversion scheme

The identification of hydrocarbons using seismic methods is critical in the prediction of shale oil res-ervoirs.However,delineating shales of high oil saturation is challenging owing to the similarity in the elastic properties of oil-and water-bearing shales.The complexity of the organic matter properties associated with kerogen and hydrocarbon further complicates the characterization of shale oil reservoirs using seismic methods.Nevertheless,the inelastic shale properties associated with oil saturation can enable the utilization of velocity dispersion for hydrocarbon identification in shales.In this study,a seismic inversion scheme based on the fluid dispersion attribute was proposed for the estimation of hydrocarbon enrichment.In the proposed approach,the conventional frequency-dependent inversion scheme was extended by incorporating the PP-wave reflection coefficient presented in terms of the effective fluid bulk modulus.A rock physics model for shale oil reservoirs was constructed to describe the relationship between hydrocarbon saturation and shale inelasticity.According to the modeling results,the hydrocarbon sensitivity of the frequency-dependent effective fluid bulk modulus is superior to the traditional compressional wave velocity dispersion of shales.Quantitative analysis of the inversion re-sults based on synthetics also reveals that the proposed approach identifies the oil saturation and related hydrocarbon enrichment better than the above-mentioned conventional approach.Meanwhile,in real data applications,actual drilling results validate the superiority of the proposed fluid dispersion attribute as a useful hydrocarbon indicator in shale oil reservoirs.

Comparison of toxicity effects of fuel oil treated by different dispersants on marine medaka(Oryzias melastigma) embryo

This study aims to evaluate the subacute toxic effects of oil under different treatments on marine organism by simulating natural contaminative processes. In this study, 120# （RMD15） fuel oil was selected as the pollutant and marine medaka （Oryzias melastigma） embryos as the experimental organism. The developmental toxicity of different volume concentrations （0.05%, 0.2%, 1% and 5%） of water-accommodated fractions, biologically-enhanced water-accommodated fractions, and chemically-enhanced water-accommodated fractions on the embryos in different exposure time （8, 15 and 22 d） were compared and the content of relevant polycyclic aromatic hydrocarbons （PAHs） was studied （in dispersion and in vivo）. The subacute toxic effects were assessed in terms of antioxidant activities of enzymes （superoxide dismutase, catalase and glutathione S-transferase） and the blue sac disease （BSD） indexes.The results showed that the BSD indexes of the treatment groups were significantly higher than the respective control groups and showed positive correlations with both concentration and exposure time. The experiments with three antioxidant enzymes indicated that enzymatic activities of the embryos changed dramatically under the oxidation stress of petroleum hydrocarbons, especially after adding the dispersants. With the increase of petroleum hydrocarbon concentration and exposure time, the three enzymes showed different degrees of induction and inhibition effects.

SURFACE MODIFICATION AND DISPERSION OF NANODIAMOND IN CLEAN OIL

The effect of different kinds of surfactants on the size distribution of nanodiamond particles in clean oil was studied. Results show that the dispersing stability of nanodiamond modified with surfactants YS-1 and SB-18 simulta-neously is much better than those modified with either of them because of synergism of the surfactants. And the particle size distribution in the system can be improved remarkably after the adoption of hyperdispersants such as SA-E and SA-F. Anchoring groups of those hyperdispersants can be bonded with the particle surface by chemical and/or hydrogen bonding and their soluble chains are well compatible with the dispersion media. As a result, the particles are uniformly distributed in the system owing to the steric stabilization. A very stable clean-oil based nanodiamond suspension with an average particle size of around 53.2 nm was prepared.