Table 7. Comparison of the Slopes of the IFT Versus Pressure Diagrams at 50 and 70 °C.

temperature	oil solution type	1st interval slope	2nd interval slope	the ratio of the slope of the 2nd interval to the 1st interval (%)
50 °C	without nanoparticles	2.07	0.31	14.83
	with nanoparticles	1.93	0.60	31.17
70 °C	without nanoparticles	1.58	0.21	13.41
	with nanoparticles	1.62	0.54	33.06