CN106000217A - Viscoelastic system formed by functional Gemini surface active agent - Google Patents

Abstract

The invention discloses a viscoelastic system formed by a functional Gemini surface active agent and belongs to the technical field of a surface active agent. According to a preparation method of a viscoelastic surface active agent solution provided by the invention, organic salt comprises sodium o-hydroxybenzoate, 3-hydroxy-benzoic aci monosodium salt and sodium p-Hydroxybenzoate; Gemini surface active agent with hydroxyl group is taken as the main component and is compounded with few organic salts, and then the viscoelastic surface active agent solution is obtained; the preparation of the viscoelastic surface active agent solution comprises the two processes of compounding and testing viscoelastic property; Gemini cationic surface active agent is prepared into the solution in certain concentration and then is compounded with the salt at different ratio, thus, the viscoelastic surface active agent solution is acquired.

Description

A Viscoelastic System Constructed by Functionalized Gemini Surfactant

technical field

The invention relates to a viscoelastic system constructed by a functionalized Gemini surfactant, belonging to the technical field of surfactants.

Background technique

Gemini surfactants, also known as gemini surfactants, twinned surfactants, twin surfactants or coupled surfactants, are two traditional surfactant molecules that are connected at or near their hydrophilic head groups through a linking group. A new type of surfactant formed by linking hydrophilic head groups together. Due to the particularity of its structure, gemini surfactants exhibit many unique properties that conventional surfactants do not possess, so they have strong application potential. Gemini surfactant has good solubilization, wetting, foaming and saponification and dispersing capabilities, and can be widely used in various fields such as daily chemical industry, food industry and tertiary oil recovery. In addition, in some special fields , For example, it can be used as template agent and anti-adhesive agent for the preparation of nanomaterials; treatment of sewage and soil; sterilization and disinfection; gene transfection; inhibition of metal corrosion; oil recovery and fine chemicals, etc.

When special groups, such as hydroxyl groups, are introduced into the structure of Gemini surfactants, the self-organized morphology of Gemini surfactants can be changed, such as worm-like micelles can be formed. The worm-like micelles refer to the thermodynamic equilibrium aggregates formed by the non-axial one-dimensional growth of surfactants. Worm-like micellar solutions are widely used in oil fields, such as oilfield fracturing fluids, thickeners, etc., and can also be used as drag reducers for fluid transportation. In addition, worm-like micellar solutions are used in cleaning products and There are also a wide range of applications in the field of cosmetics. However, the conditions for forming worm-like micelles are usually very harsh, and surfactants with special structures are generally required. Gemini surfactants can form worm-like micelles by taking advantage of their own structure and supplementing with special groups. However, usually, The formed worm-like micelles have insufficient viscoelasticity or poor stability, such as easy turbidity. In order to solve this problem, you can try to add salts to the Gemini surfactant solution. The viscoelasticity of worm-like micelles formed after adding salts is better, and changing the type of salt can form worm-like micelles of different lengths .

Contents of the invention

The invention provides a preparation method of a surfactant viscoelastic solution, which uses a Gemini surfactant with a hydroxyl group as the main component and compound it with a small amount of organic salt.

The structural formula of the Gemini surfactant with hydroxyl is as (1):

The synthetic route of described Gemini cationic surfactant is as follows:

Described organic salt is sodium o-hydroxybenzoate (o-ph-ONa), sodium meta-hydroxybenzoate (m-ph-ONa) or sodium p-hydroxybenzoate (p-ph-ONa), and structural formula is respectively as follows:

The sodium o-hydroxybenzoate, sodium m-hydroxybenzoate and sodium p-hydroxybenzoate are all commercially available.

In one embodiment of the present invention, the method is to formulate Gemini cationic surfactant into a solution with a certain concentration, and then compound it with salt in different proportions to obtain a surfactant viscoelastic solution.

In one embodiment of the present invention, the molar ratio of the organic salt to the Gemini cationic surfactant is 2:25-10:25, preferably 5:25-8:25.

In one embodiment of the present invention, organic salts and Gemini cationic surfactants are compounded according to any of the following molar ratios to obtain surfactant viscoelastic solutions: 2:25, 4:25, 5:25, 6: 25, 7:25, 8:25, 9:25 or 10:25.

In one embodiment of the invention, the Gemini cationic surfactant is fixed at a concentration of 50-80 mM.

In one embodiment of the present invention, the concentration of the organic salt is 10-16 mM.

In one embodiment of the present invention, sodium o-hydroxybenzoate and Gemini cationic surfactant are compounded according to a molar ratio of 8:25, or sodium m-hydroxybenzoate and Gemini cationic surfactant (or p-hydroxybenzene sodium formate) according to the molar ratio of 7:25.

In one embodiment of the present invention, the temperature range for compounding Gemini cationic surfactant with sodium o-hydroxybenzoate, sodium m-hydroxybenzoate and sodium p-hydroxybenzoate is controlled at 25-30°C.

Beneficial effects of the present invention

(1) the present invention obtains the solution with good viscoelasticity after three kinds of organic salts are compounded with the Gemini cationic surfactant solution containing hydroxyl group, can obviously find out that the viscoelasticity of three compound systems has obvious difference, can Prove that the change of additive microstructure will affect the self-organization behavior of surfactants, enrich the theoretical basis of surfactant self-organization behavior, and provide new ideas for the construction of surfactant aggregates;

(2) the present invention uses sodium o-hydroxybenzoate and Gemini cationic surfactant to compound according to the molar ratio of 8:25, and the zero-shear viscosity of the system is the largest, which can reach 237.14Pa·s; Sodium benzoate) and Gemini cationic surfactant compounded according to the molar ratio of 7:25, the zero-shear viscosity of the system can reach 40Pa·s and 7.41Pa·s respectively;

(3) At the same molar ratio, the Gemini cationic surfactant is mixed with three kinds of salts respectively: sodium o-hydroxybenzoate, sodium m-hydroxybenzoate and sodium p-hydroxybenzoate, the viscoelasticity of the mixed solution after compounding decreases successively; The molar ratio of sodium benzoate to Gemini cationic surfactant is in the range of 5:25 to 8:25, the obtained viscoelastic solution has good stability, clarity and good viscoelasticity, and the zero shear viscosity of the viscoelastic system is 75Pa· s or more.

Description of drawings

Fig. 1 is the dynamic shear spectrum of sodium o-hydroxybenzoate/50mM 12-3(OH)-12; G' (solid symbol, modulus of elasticity), G " (open symbol, modulus of viscosity) changes with angular frequency ω;

Fig. 2 is the steady-state shear figure of system when sodium o-hydroxybenzoate/50mM 12-3(OH)-12 is in different salt concentrations;

Fig. 3 is organic salt/50mM 12-3(OH)-12 mixed solution zero-shear viscosity change curve graph with salt concentration; Wherein o-ph-ONa is, m-ph-ONa, p-ph-ONa are respectively Sodium o-hydroxybenzoate, sodium m-hydroxybenzoate, sodium paraben.

detailed description

The preparation of embodiment 1:12-3 (OH)-12

Add 1,3-dibromo-2-propanol (10.0g, 0.046mol), N,N-dimethyldodecylamine (21.6g, 0.102mol) and 100mL of absolute ethanol to the reaction equipped with a reflux condenser In a container, heat to reflux and stir for 48 hours. After the reaction, the ethanol is removed by rotary evaporation to obtain a yellow viscous liquid. Four equal parts of the obtained crude product are transferred to four 50mL centrifuge tubes, and 30mL anhydrous ether is added to wash three times, centrifuged, poured Remove the supernatant. Then recrystallize five times in the centrifuge tube with ethanol/ether, put the centrifuge tube into a vacuum drying oven and dry for 48 hours to obtain 10.8 g of white solid product with a yield of 65%.

Example 2:

Preparation of Viscoelastic Surfactant Solutions. Prepare 80mmol/L of Gemini cationic surfactant solution and 100mmol/L of salt solution, wherein each surfactant solution takes 1.25mL, and then add appropriate amount of sodium o-hydroxybenzoate, sodium m-hydroxybenzoate and sodium p-hydroxybenzoate salt solution, so that the molar ratio of salt to Gemini cationic surfactant reaches 2:25, 4:25, 5:25, 6:25, 7:25, 8:25, 9:25, 10:25, and then Add ultrapure water so that the total volume of the mixed solution is 2 mL, and after mixing evenly, a series of viscoelastic surfactant solutions are obtained.

Embodiment 3:

The viscoelasticity measurement of the viscoelastic surfactant solution obtained by compounding salt and cationic surfactant solution in Example 2.

The resulting viscoelastic surfactant solution was left to stand at 25°C for 48 hours, and the rheological properties were tested at 25°C. Before the dynamic scanning, the stress scanning is carried out to determine the linear viscoelastic region of the test sample, and the tests of the samples are all carried out in the linear viscoelastic region. See Figure 1, Figure 2 and Figure 3 for specific data:

Fig. 1 is the dynamic shear diagram of sodium o-hydroxybenzoate/50mM 12-3(OH)-12, as can be seen, in the tested frequency range, the elastic modulus of the sample is always greater than the viscous modulus, indicating that the sample has a good flexibility.

Figure 2 is the steady-state shear diagram of the sample. As the salt concentration increases, the zero-shear viscosity of the sample first increases and then decreases. When the molar ratio of sodium o-hydroxybenzoate to Gemini cationic surfactant is 8:25, the zero-shear viscosity can reach the maximum value of 237.14Pa·s. In addition, the inventor also tried to prepare a viscoelastic solution by compounding sodium o-hydroxybenzoate with 12-3-12 (compared with 12-3(OH)-12, there is no hydroxyl group on the linking chain), and found that The maximum zero-shear viscosity of the mixed system of 12-3-12 and sodium o-hydroxybenzoate is 30Pa·s, if the salt concentration continues to increase, turbidity will appear. This shows that the viscoelasticity of the viscoelastic solution compounded by 12-3(OH)-12 and sodium o-hydroxybenzoate in the present invention has obvious advantages.

Fig. 3 is salt/50mM 12-3(OH)-12 mixed solution zero-shear viscosity changes curve graph with salt concentration, when same molar ratio, Gemini cationic surfactant is respectively mixed with three kinds of salts: sodium o-hydroxybenzoate , sodium m-hydroxybenzoate and sodium p-hydroxybenzoate, the viscoelasticity of the mixed solution decreases successively after compounding. When the molar ratio of sodium o-hydroxybenzoate to Gemini cationic surfactant is in the range of 5:25 to 8:25, the zero-shear viscosity of the viscoelastic system is above 75Pa·s, and the solution remains clear.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore The scope of protection of the present invention should be defined by the claims.

Claims (10)

1. the preparation method of a surfactant viscoelastic solution, it is characterised in that described method is that use is hydroxyl Gemini surface active is main component, compounds with a small amount of organic salt；The knot of described hydroxyl Gemini surface active Structure formula is as follows:

Method the most according to claim 1, it is characterised in that described organic salt is oxybenzoic acid sodium, a hydroxy benzenes Sodium formate or P-hydroxybenzoic acid sodium.

Method the most according to claim 1, it is characterised in that organic salt and Gemini cationic surfactant mole Ratio is 2:25～10:25, preferably 5:25～8:25.

Method the most according to claim 1, it is characterised in that described organic salt with Gemini cationic surfactant is According to mol ratio 2:25,4:25,5:25,6:25,7:25,8:25,9:25 or 10:25, compounding to obtain surfactant viscoelastic molten Liquid.

Method the most according to claim 1, it is characterised in that described Gemini cationic surfactant concentration is 50- 80mM。

Method the most according to claim 5, it is characterised in that described organic salt concentration is 10-16mM.

Method the most according to claim 1, it is characterised in that described method is by oxybenzoic acid sodium and Gemini sun Ionic surface active agent is that 5:25～8:25 compounds according to mol ratio, or by m-hydroxybenzoic acid sodium or P-hydroxybenzoic acid Sodium compounds according to mol ratio 7:25 with Gemini cationic surfactant.

8. according to the method described in claim 1-7, it is characterised in that described method is by Gemini cationic surfactant It is made into certain density solution, then compounds according to different mol ratio with salt, i.e. can get surfactant viscoelastic solution.

9. the surfactant viscoelastic solution obtained according to the arbitrary described method of claim 1-7.

10. the surfactant viscoelastic solution of claim 9 application in daily use chemicals industry, food industry and tertiary oil recovery.