Synthesis and Interface Activity of a Series of Carboxylic Quaternary Ammonium Surfactants in Hydraulic Fracturing

Figure 4

Change of foam height and with different temperatures over various surfactants: (a) 30°C, (b) 40°C, (c) 50°C, (d) 60°C, and (e) 70°C.

(a)

(b)

(c)

(d)

(e)