Double Phase Inversion of Pickering Emulsion Induced by Magnesium Hydroxide Nanosheets Adsorbed with Sodium Dodecyl Sulfate.
Double Phase Inversion of Pickering Emulsion Induced by Magnesium Hydroxide Nanosheets Adsorbed with Sodium Dodecyl Sulfate.
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DOI：
10.1021/acs.langmuir.0c03415
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发表时间：
2021-03
期刊：
影响因子：
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通讯作者：
Pei Zhu;Feng Wang;Yanfen Ding;Shimin Zhang;Chong Gao;Peng Liu;Mingshu Yang
中科院分区：
文献类型：
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作者：
Pei Zhu;Feng Wang;Yanfen Ding;Shimin Zhang;Chong Gao;Peng Liu;Mingshu Yang
表面活性剂常与固体颗粒作为协同稳定剂，以提高酸洗乳的效率。因此，表面活性剂与固体颗粒之间的相互作用对皮克林乳状液稳定性的影响一直受到人们的关注。本研究设计了不同用量十二烷基硫酸钠（SDS）表面活性剂吸附的氢氧化镁（MH）纳米片，并将其用于稳定石蜡-水乳液。采用sds吸附的MH纳米片作为稳定剂，发现了皮克林乳的双相转化现象。Pickering乳状液在MH纳米片上的SDS吸附量约为0.022 mmol/g时，由0 /W转变为W/O，随后以2.312 mmol/g左右的吸附量恢复为0 /W。第一个相反转是由于改性MH纳米片的疏水性增加，SDS分子被单层吸附在MH纳米片表面。由于SDS在MH纳米片上的双层吸附，使改性后的MH纳米片再次发生亲水性转变。这些结果对于理解添加表面活性剂后Pickering乳状液的双相转化，以及在可逆钻井液和采油等领域的应用前景具有重要意义。
Surfactants are often used as a cooperation stabilizer with solid particles for increasing the efficiency of Pickering emulsion. Accordingly, the effects of interaction between surfactants and solid particles on stabilizing Pickering emulsions have been attracting great attention. In this study, magnesium hydroxide (MH) nanosheets adsorbed with different amounts of sodium dodecyl sulfate (SDS) surfactants were designed and used to stabilize paraffin-water emulsions. Using SDS-adsorbed MH nanosheets as a stabilizer, the phenomenon of double phase inversion was found for Pickering emulsion. Pickering emulsion was inverted initially from O/W to W/O at about 0.022 mmol/g of the adsorption amount of SDS on the MH nanosheets, and subsequently back to O/W at about 2.312 mmol/g. The first phase inversion was because of the increased hydrophobicity of modified MH nanosheets, where SDS molecules were monolayer-adsorbed on the MH nanosheets surface. The second phase inversion occurred due to the bilayer adsorption of SDS on MH nanosheets, which converted the modified MH nanosheets hydrophilic again. These results are of great importance to understanding the double phase inversion of Pickering emulsions with the addition of surfactants and finding prospective applications in fields such as reversible drilling fluids and oil extraction.