LAUSR

Abstract Montmorillonite (Mt) was modified with three nonionic surfactants, i.e., Span-80, Span-20 and OP-10. The influence of the structures and properties of nonionic surfactants on the structures and properties of organo-montmorillonite (OMt) was researched. X-ray diffraction results demonstrated that nonionic surfactants with low Hydrophile-Lipophile Balance (HLB) values could not intercalate into the interlayer space of Mt while surfactants with high HLB values could. Scanning electron microscope images indicated that the modified Mt was disaggregated into thin lamellas, instead of big particles. Surfactants were able to help to disperse Mt in water. Contact angle tests showed that the hydrophobicity of OMt was higher than raw Mt. However, the hydrophobicity of OMt was not as high as expected. The highest contact angle of OMt was 52°. With the increase of HLB values of nonionic surfactants, the hydrophobicity of OMt gradually decreased. The swelling ability of OMt in organic solvents was poor. The swelling ability of OMt was related to the structure of OMt and the HLB values of nonionic surfactants. Finally, the different mechanisms of OMt prepared with different nonionic surfactants were discussed.