Study on the modification of the expansion behavior of organic bentonite by the compound of molecular deposition filming flooding agent with alkyl quaternary ammonium salts

Taking the compound solutions of a molecular deposition filming flooding agent (MDFFA) separately with tetraethyl ammonium bromide [(Et)4NB],dodecyl trimethyl ammonium bromide (DTAB) and hexadecyl trimethyl ammonium bromide (CTAB) as modifiers,the expansion behavior of organic bentonite is modified.The distance between crystal layers of the modified bentonites is investigated.The modified bentonites are characterized by X-ray diffraction (XRD),fourier transform infrared spectrometer (FT-IR) and thermogravimetric (TG) analysis.The results show that,compared with molecular deposition filming flooding agent alone,the compound modifiers make bentonite have less interlayer distance and therefore they have better anti-swelling effect on bentonite.At the same concentration,the adsorption capacity of bentonite to (Et)4NB or MDFFA is less than that to DTAB or CTAB.And the adsorption capacity of bentonite to the compound modifier of MD with DTAB or CTAB is greater than that to MDFFA alone.