Author Contributions
Conceptualization, X.M. and X.L. (Xiaofei Liu); methodology, H.Y. and X.L. (Xiaofei Liu); validation, H.Y. and Y.Y.; formal analysis, X.M.; investigation, X.M. and X.L. (Xinzi Li); resources, H.Y., L.Z. (Lixiang Zeng) and L.Z. (Lijun Zheng); data curation, L.C. and W.M.; writing—original draft preparation, X.M.; writing—review and editing, X.M. and H.Y.; supervision, X.L. (Xiaofei Liu), H.Y. and J.Z. All authors have read and agreed to the published version of the manuscript.
Figure 1.
Synthesis of copper quantum dot/polyacrylamide composite nanospheres.
Figure 1.
Synthesis of copper quantum dot/polyacrylamide composite nanospheres.
Figure 2.
Apparatuses of nanofluid spreading experiment.
Figure 2.
Apparatuses of nanofluid spreading experiment.
Figure 3.
Apparatuses of microchannel chip oil displacement experiment.
Figure 3.
Apparatuses of microchannel chip oil displacement experiment.
Figure 4.
FT-IR spectra of the copper quantum dot/polyacrylamide composite nanospheres.
Figure 4.
FT-IR spectra of the copper quantum dot/polyacrylamide composite nanospheres.
Figure 5.
Particle size chart of copper quantum dot/polyacrylamide composite nanospheres.
Figure 5.
Particle size chart of copper quantum dot/polyacrylamide composite nanospheres.
Figure 6.
TEM of copper quantum dot/polyacrylamide composite nanospheres: (a) Emulsion; (b) Dry powder.
Figure 6.
TEM of copper quantum dot/polyacrylamide composite nanospheres: (a) Emulsion; (b) Dry powder.
Figure 7.
TEM-EDS of copper quantum dot/polyacrylamide composite nanospheres powder.
Figure 7.
TEM-EDS of copper quantum dot/polyacrylamide composite nanospheres powder.
Figure 8.
TG and DTG of the copper quantum dot/polyacrylamide composite nanospheres.
Figure 8.
TG and DTG of the copper quantum dot/polyacrylamide composite nanospheres.
Figure 9.
Images of 0.1 wt% copper quantum dot/polyacrylamide composite nanosphere dry powder dispersion at different temperatures for nanofluid spreading experiments: (a) 25 °C, experimental initial plots; (b) 25 °C, experimental 60 min effect plots; (c) 65 °C, experimental initial plots; (d) 65 °C, experimental 60 min effect plots.
Figure 9.
Images of 0.1 wt% copper quantum dot/polyacrylamide composite nanosphere dry powder dispersion at different temperatures for nanofluid spreading experiments: (a) 25 °C, experimental initial plots; (b) 25 °C, experimental 60 min effect plots; (c) 65 °C, experimental initial plots; (d) 65 °C, experimental 60 min effect plots.
Figure 10.
Schematic of the experimental procedure for nanofluid spreading experiments with 6 mmol/L SDS solution at 25 °C. (a) Experimental initial plots; (b) Experimental 6 min effect plots; (c) Experimental 49 min effect plots.
Figure 10.
Schematic of the experimental procedure for nanofluid spreading experiments with 6 mmol/L SDS solution at 25 °C. (a) Experimental initial plots; (b) Experimental 6 min effect plots; (c) Experimental 49 min effect plots.
Figure 11.
Final effect plots of nanofluid spreading experiments with different systems at (a) 25 °C and (b) 65 °C: (a1,b1) 6 mmol/L SDS; (a2,b2) 0.1 wt% copper quantum dot/polyacrylamide composite nanosphere dry powder dispersion containing 6 mmol/L SDS; (a3,b3) 0.1 wt% acrylamide copolymer nanosphere dry powder dispersion containing 6 mmol/L SDS; (a4,b4) 100 ppm copper quantum dot dispersion containing 6 mmol/L SDS.
Figure 11.
Final effect plots of nanofluid spreading experiments with different systems at (a) 25 °C and (b) 65 °C: (a1,b1) 6 mmol/L SDS; (a2,b2) 0.1 wt% copper quantum dot/polyacrylamide composite nanosphere dry powder dispersion containing 6 mmol/L SDS; (a3,b3) 0.1 wt% acrylamide copolymer nanosphere dry powder dispersion containing 6 mmol/L SDS; (a4,b4) 100 ppm copper quantum dot dispersion containing 6 mmol/L SDS.
Figure 12.
Schematic mechanism of nanoparticles for enhanced fluid wetting and crude oil removal.
Figure 12.
Schematic mechanism of nanoparticles for enhanced fluid wetting and crude oil removal.
Figure 13.
Real-time images and blue channel histograms before and after microchannel chip oil displacement experiments with 5‰ copper quantum dot/polyacrylamide composite nanosphere emulsion dispersion at different experimental conditions. (a) Pore inner diameter of 50–200 μm, temperature of 25 °C, dispersing medium of deionized water. (b) Pore inner diameter of 5–50 μm, temperature of 25 °C, dispersing medium of deionized water. (c) Pore inner diameter of 5–50 μm, temperature of 65 °C, dispersing medium of deionized water. (d) Pore inner diameter of 50–200 μm, temperature of 25 °C, dispersing medium of injected water.
Figure 13.
Real-time images and blue channel histograms before and after microchannel chip oil displacement experiments with 5‰ copper quantum dot/polyacrylamide composite nanosphere emulsion dispersion at different experimental conditions. (a) Pore inner diameter of 50–200 μm, temperature of 25 °C, dispersing medium of deionized water. (b) Pore inner diameter of 5–50 μm, temperature of 25 °C, dispersing medium of deionized water. (c) Pore inner diameter of 5–50 μm, temperature of 65 °C, dispersing medium of deionized water. (d) Pore inner diameter of 50–200 μm, temperature of 25 °C, dispersing medium of injected water.
Table 1.
ICP test result of copper quantum dot/polyacrylamide composite nanospheres.
Table 1.
ICP test result of copper quantum dot/polyacrylamide composite nanospheres.
Sample | Sample Volume (g) | Calibration Volume (mL) | Test Concentration ± 0.0006 (mg/L) | Dilution Factor | Copper Content ± 0.3 (mg/L) |
---|
Emulsion | 0.1110 | 25 | 0.1732 | 225.23 | 39.0 |
Dry powder | 0.0523 | 25 | 0.4186 | 478.01 | 200.1 |
Table 2.
Crude oil removal time with different systems at different temperatures.
Table 2.
Crude oil removal time with different systems at different temperatures.
Sample | 25 °C | 65 °C |
---|
SDS | 49 min | 308 s |
Cu/PAM NPs + SDS | 7 min | 37 s |
PAM NPs + SDS | 15 min | 62 s |
Cu QDs + SDS | 37 min | 101 s |
Table 3.
Oil displacement efficiency of different samples (large channel, 25 °C, deionized water).
Table 3.
Oil displacement efficiency of different samples (large channel, 25 °C, deionized water).
Sample | Initial Area | Remaining Area | Displacement Area | Displacement Efficiency (%) |
---|
Cu/PAM NPs | 406,297 | 14,546 | 391,751 | 96.42 |
PAM NPs | 406,297 | 22,590 | 383,707 | 94.44 |
Cu QDs | 406,297 | 17,714 | 388,583 | 95.64 |
Table 4.
Oil displacement efficiency of different samples (small channel, 25 °C, deionized water).
Table 4.
Oil displacement efficiency of different samples (small channel, 25 °C, deionized water).
Sample | Initial Area | Remaining Area | Displacement Area | Displacement Efficiency (%) |
---|
Cu/PAM NPs | 300,289 | 15,972 | 284,317 | 94.68 |
PAM NPs | 300,289 | 69,242 | 231,047 | 76.94 |
Cu QDs | 300,289 | 24,221 | 276,068 | 91.93 |
Table 5.
Oil displacement efficiency of different samples (small channel, 65 °C, deionized water).
Table 5.
Oil displacement efficiency of different samples (small channel, 65 °C, deionized water).
Sample | Initial Area | Remaining Area | Displacement Area | Displacement Efficiency (%) |
---|
Cu/PAM NPs | 300,289 | 11,470 | 288,819 | 96.18 |
PAM NPs | 300,289 | 49,332 | 250,957 | 83.57 |
Cu QDs | 300,289 | 61,538 | 238,751 | 79.51 |
Table 6.
Oil displacement efficiency of different samples (large channel, 25 °C, injected water).
Table 6.
Oil displacement efficiency of different samples (large channel, 25 °C, injected water).
Sample | Initial Area | Remaining Area | Displacement Area | Displacement Efficiency (%) |
---|
Cu/PAM NPs | 394,111 | 19,160 | 374,951 | 95.14 |
PAM NPs | 394,111 | 52,314 | 341,797 | 86.73 |
Cu QDs | 394,111 | 91,011 | 303,100 | 76.91 |