**2. Classification**

Gemini imidazoline surfactant can by classified on the basis physicochemical characterisitics.

#### **2.1 On the basis of charge**

Gemini imidazolinium belongs to the cationic gemini group but they are also amphoteric in nature. The imidazolinium gemini surfactant are dimeric molecules formed by two head groups associated with the spacer group and two hydrophobic tails [26] (**Figure 3**).

**67**

*2.1.1 Cationic charge*

*Gemini imdazoline surfactant.*

**Figure 3.**

*2.1.2 Amphoteric charge*

**2.2 On the basis of spacer**

properties [30, 31] (**Table 1**).

hydrophobic tails [30].

**2.3 On the basis of hydrophobic tail**

*Gemini Imidazolinium Surfactants: A Versatile Class of Molecules*

The head group in the gemini imidazolinium surfactants contains the positive charge. It possesses long alkyl group, two polar imidazolinium head group and two tails of hydrocarbon in which head groups are linked by a spacer. They are soluble in organic solvents and dispense in water, eg., imidazoline-based dissymmetric

The head group carries both negative and positive charge groups. They maintained the stability at acidic and basic pH of the solution, soluble in water, e.g.

The rigidity, length, polarity of the spacer can vary and leads to the variation in the structure of the gemini imidazoline surfactant as well as the in the surface

The variation in the hydrocarbon chain/tail can change the properties of surfactant. The chain can have two identical hydrophobic tails and two non-identical

bis-quaternary ammonium Gemini surfactant [26–28].

bisalkyl-bisimidazoline surfactant [26, 27, 29].

*DOI: http://dx.doi.org/10.5772/intechopen.94209*

*Gemini Imidazolinium Surfactants: A Versatile Class of Molecules DOI: http://dx.doi.org/10.5772/intechopen.94209*

**Figure 3.** *Gemini imdazoline surfactant.*
