نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی کارشناسی ارشد دانشکده عمران دانشگاه خواجه نصیر
2 دانشیار گروه عمران دانشکده فنی و مهندسی دانشگاه خوارزمی
3 دانشجوی دکتری گروه عمران دانشکده فنی و مهندسی دانشگاه خوارزمی
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Abstract: Carbon nanotubes, owing to their high electrical conductivity, large aspect ratio, and excellent mechanical properties, are among the most important additives used in self-sensing concrete. However, the strong tendency of these nanomaterials to aggregate and form clusters due to van der Waals attractive forces is one of the major obstacles to achieving desirable electri-cal and piezoresistive performance in cementitious composites containing carbon nanotubes. The use of surfactants, as one of the most common dispersion methods, plays an important role in improving the distribution of carbon nanotubes and enhancing their efficiency in cementitious environments. In this study, the experimental behavior of self-sensing cementitious composites containing carbon nanotubes was investigated. Subsequently, four commonly used surfactants, namely sodium dodecyl sulfate (SDS), sodium dodecylbenzene sulfonate (SDBS), carboxyme-thyl cellulose (CMC), and cetyltrimethylammonium bromide (CTAB), were compared from mo-lecular and mechanistic perspectives. For this purpose, molecular models of carbon nanotubes and surfactants were developed, and their interactions were analyzed using molecular dynamics simulation. Interaction energy, molecular arrangement on the carbon nanotube surface, and the stability of the formed structures were considered as evaluation criteria. The results showed that, under the investigated conditions, CMC exhibited a greater capability for stabilizing carbon nanotubes due to its more favorable arrangement around the carbon nanotube and more effective contact with the CNT surface. However, the performance of surfactants in real cementitious en-vironments depends on a range of factors, including compatibility with the cement matrix, air-entraining effects, compressive strength, density, electrical response, and long-term stability.
کلیدواژهها [English]
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