Cr(III)ehydrolyzed polyacrylamide(HPAM)gels have been extensively studied as a promising strategy controlling waste water production for mature oilfields.However,the gelation time of the current technologies is not lo...Cr(III)ehydrolyzed polyacrylamide(HPAM)gels have been extensively studied as a promising strategy controlling waste water production for mature oilfields.However,the gelation time of the current technologies is not long enough for in-depth placement.In this study,we report a novel synthesis method to obtain chromium chloride/poly(methyl methacrylate)(PMMA)nanocapsules which can significantly delay the gelation of HPAM through encapsulating the chromium chloride crosslinker.The chromium chloride-loaded nanocapsules(CreNC)are prepared via a facile inverse miniemulsion evaporation method during which the hydrophobic PMMA polymers,pre-dispersed in an organic solvent,were carefully controlled to precipitate onto stable aqueous miniemulsion droplets.The stable aqueous nanodroplets(W)containing Cr(III)are dispersed in a mixture of organic solvent(O1)with PMMA and nonsolvent medium(O2)to prepare an inverse miniemulsion.With the evaporation of the O1,PMMA forms CreNCs around the aqueous droplets.The CreNCs are readily transferred into water from the organic nonsolvent phase.The CreNCs exhibit the tunable size(358-983 nm),Cr loading(7.1%-19.1%),and Cr entrapment efficiency(11.7%-80.2%),with tunable zeta potentials in different PVA solutions.The CreNCs can delay release of Cr(III)and prolong the gelation time of HPAM up to 27 days.展开更多
The effects of petroleum sulphonate, HPAM and pH value on the zeta potential of Na-montmo-（rrillonite） suspensions were investigated, and orthogonal design of experiment was used to study the effect of these factors...The effects of petroleum sulphonate, HPAM and pH value on the zeta potential of Na-montmo-（rrillonite） suspensions were investigated, and orthogonal design of experiment was used to study the effect of these factors on the zeta potential of montmorillonite suspensions when the three factors existed simultaneously. The results show that the zeta potential of montmorillonite becomes more negative with the increase of the concentration of petroleum sulphonate, that of HPAM, and the pH value. Moreover, FpH=13.3(>F0.01=9.78), FHPAM=7.73(>F0.05=4.76) and Fpetroleum sulfonate=3.05 when the three factors co-exist, thus the effect of pH value on the zeta potential of montmorillonite is the most prominent factor, the HPAM a less prominent factor, and the petroleum sulphonate is least prominent.展开更多
基金The authors were also supported by the National Natural Science Foundation of China(grant number 52104057 and 52204041)Natural Science Foundation of Shandong Province(grant number ZR2021QE106)China Postdoctoral Science Foundation(grant number 2021M693506)during the writing of this paper at China University of Petroleum(East China).
文摘Cr(III)ehydrolyzed polyacrylamide(HPAM)gels have been extensively studied as a promising strategy controlling waste water production for mature oilfields.However,the gelation time of the current technologies is not long enough for in-depth placement.In this study,we report a novel synthesis method to obtain chromium chloride/poly(methyl methacrylate)(PMMA)nanocapsules which can significantly delay the gelation of HPAM through encapsulating the chromium chloride crosslinker.The chromium chloride-loaded nanocapsules(CreNC)are prepared via a facile inverse miniemulsion evaporation method during which the hydrophobic PMMA polymers,pre-dispersed in an organic solvent,were carefully controlled to precipitate onto stable aqueous miniemulsion droplets.The stable aqueous nanodroplets(W)containing Cr(III)are dispersed in a mixture of organic solvent(O1)with PMMA and nonsolvent medium(O2)to prepare an inverse miniemulsion.With the evaporation of the O1,PMMA forms CreNCs around the aqueous droplets.The CreNCs are readily transferred into water from the organic nonsolvent phase.The CreNCs exhibit the tunable size(358-983 nm),Cr loading(7.1%-19.1%),and Cr entrapment efficiency(11.7%-80.2%),with tunable zeta potentials in different PVA solutions.The CreNCs can delay release of Cr(III)and prolong the gelation time of HPAM up to 27 days.
文摘The effects of petroleum sulphonate, HPAM and pH value on the zeta potential of Na-montmo-（rrillonite） suspensions were investigated, and orthogonal design of experiment was used to study the effect of these factors on the zeta potential of montmorillonite suspensions when the three factors existed simultaneously. The results show that the zeta potential of montmorillonite becomes more negative with the increase of the concentration of petroleum sulphonate, that of HPAM, and the pH value. Moreover, FpH=13.3(>F0.01=9.78), FHPAM=7.73(>F0.05=4.76) and Fpetroleum sulfonate=3.05 when the three factors co-exist, thus the effect of pH value on the zeta potential of montmorillonite is the most prominent factor, the HPAM a less prominent factor, and the petroleum sulphonate is least prominent.
