THE USE OF MICROEMULSIONS AS CLEANING MEDIA - THE USE OF MICROEMULSIONS IN MODEL DETERGENCY EXPERIMENTS AS WASHING MEDIA FOR OIL AND PIGMENT SOILED TEST FABRICS

Making use of the knowledge of the phase diagrams from the quaternary systems water/n-undecane/C-12/14 alkylpolyglycol ether/n-pentanol as w ell homogeneous microemulsions and two or three phase systems were use d in model detergency experiments as washing media for oil and pigment soiled test fabrics The n-undecane has a purity of > 95 wt-% n-undeca ne (Halpaclean UN(R). The alkylpolyglycol ethers were commercial grade products C(i)E(j), numbers j = 4, 5, 6, 7, and 8. The composition of the cleaning media was varied either by alkylpolyglycol ethers with hy drocarbon chain lengths between i = 12 and i = 14 and with mean ethoxy lation changing of the mean ethoxylation number of the alkylpolyglycol ethers or by adding specified amounts of n-pentanol. The detergency o f selected microemulsions of the above mentioned ternary systems for o il- and pigment-soiled test fabrics was compared with the detergency o f a standard detergents solution. The results of the detergency tests showed that the detergency in the microemulsions at low temperatures o f < 313 K is notably higher than that of a standard detergent solution . The optimum detergency of the used microemulsion systems corresponds to a minimum of the interfacial tension of approximate to 10(-3) mN m (-1) between the microemulsion and the water or oil excess phase in th e heterogeneous regions of the phase diagrams. From the results of our detergency experiments it follows that the detergency of the microemu lsions can be optimized by varying their composition: The ethoxylation numbers (j) and concentrations of the nonionics, the concentration of the hydrocarbon component (> 95 % n-undecane), the co-surfactant (n-p entanol) and the temperature. From the results we can conclude that mi croemulsions are suitable for cleaning especially of oil-soiled fabric s.