This paper reports a study undertaken to achieve a compatible and affordable technique for the high-quality dispersion of carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) in an aqueous suspension to be used in multifunctional cementitious composites. In this research work, two noncovalent surfactants with different dispersion mechanisms (Pluronic F-127 (nonionic) and sodium dodecylbenzene sulfonate (SDBS) (ionic)) were used. We evaluated the influences of various factors on the dispersion quality, such as the surfactant concentration, sonication time, and temperature using UV-visible spectroscopy, optical microscopic image analysis, zeta potentials, and particle size measurement. The effect of tributyl phosphate (TBP) used as an antifoam agent was also evaluated. The optimum suspensions of each surfactant were used to produce cementitious composites, and their mechanical, microstructural, electrical, and thermal behaviors were assessed and analyzed. The best dispersed CNT+GNP aqueous suspensions using Pluronic and SDBS were obtained for concentrations of 10% and 5%, respectively, with 3 hours of sonication, at 40°C, with TBP used for both surfactants. The results also demonstrate that cementitious composites reinforced with CNT+GNP/Pluronic showed better mechanical performance and microstructural characteristics due to the higher quality of the dispersion and the increasing hydration rate. Composites prepared with an SDBS suspension demonstrated lower electrical and thermal conductivities compared to those of the Pluronic suspension due to changes in the intrinsic properties of CNTs and GNPs by the SDBS dispersion mechanism.

中文翻译：

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CNT / GNP混合分散的有效方法及其对多功能水泥基复合材料的机械，微观结构，热和电性能的影响

本文报道了一项研究，旨在实现兼容和负担得起的技术，以将碳纳米管（CNT）和石墨烯纳米片（GNP）高质量分散在用于多功能胶凝复合材料的水性悬浮液中。在这项研究工作中，使用了两种具有不同分散机理的非共价表面活性剂（Pluronic F-127（非离子）和十二烷基苯磺酸钠（SDBS）（离子））。我们使用紫外可见光谱，光学显微图像分析，ζ电位和粒度测量评估了各种因素对分散质量的影响，例如表面活性剂浓度，超声处理时间和温度。还评估了磷酸三丁酯（TBP）用作消泡剂的效果。使用每种表面活性剂的最佳悬浮液来生产水泥复合材料，并评估和分析它们的机械，微观结构，电和热行为。使用Pluronic和SDBS获得的最佳分散的CNT + GNP水性悬浮液的浓度分别为10％和5％，在40°C超声处理3小时，两种表面活性剂均使用TBP。结果还表明，由于分散液质量更高和水化速率提高，用CNT + GNP / Pluronic增强的水泥基复合材料具有更好的机械性能和微观结构特征。