Performance Of Sodium Monoalkylated Diphenyl Oxide Disulfonates And Mixed System

Alkyl diphenyl ether disulfonates are a class of anionic surfactants with two hydrophilic groups.Compared with traditional surfactants with one hydrophilic group,alkyl diphenyl ether disulfonates possesses excellent water solubility,good salt tolerance and excellent temperature-resistant.These excellent properties make the alkyl diphenyl ether disulfonates have broad application prospects in the detergent industry,tertiary oil recovery and soil remediation industries.In this thesis,effect of hydrophobic chain lengths on the properties of monoalkyl diphenyl ether disulfonates?C_n-MADS?was studied.At the same time,performance of C_n-MADS/anionic surfactant linear alkylbenzene sulfonate?LAS?and C_n-MADS/cationic surfactant cetyltrimethylammonium chloride?CTAC?mixed systems was investigated.The main work of the thesis can be divided into:1.The effect of the hydrophobic chain length of C_n-MADS on its surface activity,wetting properties,foam properties and emulsifying properties was investigated.The results show that with increasing the length of the hydrophobic carbon chain,the critical micelle concentration?cmc?of C_n-MADS?n=6,10 and 16?decreases,the efficiency of adsorption of surfactant(pC₂₀)decreases,the diffusion coefficient decreases,the surface tension(?_cmc)at cmc increases,the wetting time increases,the foam properties decreases,and the emulsifying properties have no significant change;with increasing the hydrophobic chain branching degree(such as C₁₂-MADS),surface excess concentration(?_max)decreases,pC₂₀0 increases,and the wetting time is shortened.2.The stability,hard water resistance,salt or calcium tolerance and surface tension of C₁₆-MADS/LAS mixed system were investigated.The results show that with the increase of C₁₆-MADS mass ratio,the stability,hard water resistance and salt/calcium tolerance of C₁₆-MADS/LAS solution are enhanced,?_cmcmc value increases,ideal critical micelle concentration value decreases,and the actual cmc value increases first and then decreases,which proves that there is antagonism between C₁₆-MADS and LAS,and the antagonism is strongest when the mass ratio of C₁₆-MADS/LAS is 2/8.3.The application performance of C₁₆-MADS/LAS mixed system was investigated.The results show that with increasing the mass ratio of C₁₆-MADS,the contact angle of the compound system increases,and the foam performance decreases.Under different temperatures,the higher the temperature,the greater the rate of the value of detergency of the C₁₆-MADS/LAS mixed system to the three types of soils?Carbon black oil stains,protein stains and sebum stains,abbreviated as JB-01,JB-02 and JB-03,respectively?,the higher the detergency;Under the same temperature,as the mass ratio of C₁₆-MADS increases,the rate of the value of detergency of JB-01 didn't change significantly,and the rate of the value of detergency and washing efficiency of JB-02 and JB-03 increase.Under different water hardness conditions,the water hardness increases and the detergency decreases;Under the same water hardness,with increasing the C₁₆-MADS mass ratio,the rate of the value of detergency and washing efficiency of JB-02 and JB-03 increase;When the water hardness is 750 ppm,as the C₁₆-MADS mass ratio increases,the rate of the value of detergency of JB-01 decreases first and then increases,and when C₁₆-MADS/LAS=4/6,the rate of the value of detergency of the mixed system is the lowest.4.The stability,interfacial tension and emulsifying properties of the C₁₆-MADS/CTAC mixed system were investigated.The results show that the stability of the C₁₆-MADS/CTAC mixed system is higher than that of LAS/CTAC.When C₁₆-MADS/CTAC=5/5,the C₁₆-MADS/CTAC mixed system shows strong synergistic effect in reducing the oil/water interfacial tension,and the equilibrium interfacial tension reaches the lowest;At the same time,the mixed system shows obvious antagonism in reducing the emulsifying properties,and the emulsifying performance reaches the lowest.