Amphiphilic graphene oxide (A-GO) with grafted octylamine was prepared via a one-step method of N,N′-dicyclohexylcarbodiimide coupling and epoxide ring opening at a mild temperature of 40 °C. The phase of oil–water emulsion stabilized by the complexes of A-GO and the cetyltrimethyl ammonium bromide (CTAB) surfactant could invert three times by adding CTAB or A-GO. This process was called triple phase inversion, which was a function of the concentration of A-GO or CTAB surfactants. The conductivity and zeta potential measurements confirmed that CTAB could influence the carboxyl ionization of A-GO. In addition, the turbidity of the A-GO and CTAB mixed dispersion system revealed that the appearance and disappearance of precipitation occurred when CTAB or A-GO concentration was increased. Meanwhile, the emulsion prepared by mixing the dispersion with an equal volume of xylene at a fixed CTAB concentration also showed triple phase inversion as the A-GO concentration varied. Results indicated that the stability of the emulsion and the size of the emulsion droplets had a certain correlation during the phase inversion process, which varied with the concentration of CTAB or A-GO.

中文翻译：

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两性氧化石墨烯和阳离子表面活性剂稳定的乳液的三相反相

通过N，N的一步法制备了带有接枝辛胺的两亲氧化石墨烯（A-GO）。在40°C的温和温度下，'-二环己基碳二亚胺偶联和环氧化物开环。通过添加CTAB或A-GO，由A-GO和十六烷基三甲基溴化铵（CTAB）表面活性剂的配合物稳定的油水乳液相可以反转3次。此过程称为三相转化，这是A-GO或CTAB表面活性剂浓度的函数。电导率和ζ电势测量结果证实CTAB可以影响A-GO的羧基电离。此外，A-GO和CTAB混合分散体系的浊度表明，当CTAB或A-GO浓度增加时，会出现沉淀的出现和消失。与此同时，通过将分散液与等体积的二甲苯以固定的CTAB浓度混合制备的乳液，随着A-GO浓度的变化，也显示出三相转化。结果表明，在相转化过程中，乳液的稳定性和液滴的大小具有一定的相关性，随CTAB或A-GO的浓度而变化。