Publicação
Characterizing dispersion and long term stability of concentrated carbon nanotube aqueous suspensions for fabricating ductile cementitious composites
| Resumo: | This paper reports a systematic attempt of preparing concentrated aqueous suspensions (up to 0.3 wt.%) of different types of carbon nanotubes (CNTs) using Pluronic F-127 for developing ductile cementitious composites. Single-walled and multi-walled nanotubes, both pristine and functionalized, were dispersed in water using a short (1 h) and mediumenergy (80 W)ultrasonication process using pluronic at high concentrations (above critical micelle concentration, 1–5 wt.%) and also using sodium dodecylbenzene sulphonate (SDBS) for comparison purpose. The CNT suspensionswere characterized for agglomerate area, particle size, zeta potential, extractability and long-term storage stability for a period over 4 years. The optimum suspensions were used to fabricate cementitious composites and their fracture behavior was characterized. Experimental results suggested that the optimum pluronic concentrations (1% for 0.1% CNT, 5% for 0.2% and 0.3% CNT, all in weight percent) provided highly homogeneous CNT dispersion with very lowarea of agglomerates. The best dispersion qualitywas obtained with f-SWCNT/pluronic system, which provided very low agglomerate area (b0.5%), lower CNT bundle size, good quantity of well dispersed nanotubes (up to 50%) and excellent long term storage stability. Cementitious composites fabricated using SWCNT and f-SWCNT suspensions showed ductile fracture behavior and improvement in fracture energy up to 164%. |
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| Autores principais: | Parveen, Shama |
| Outros Autores: | Rana, Sohel; Fangueiro, Raúl; Paiva, M. C. |
| Assunto: | Carbon nanotube Pluronic F-127 Extractability Zeta potential Long-term stability Engenharia e Tecnologia::Engenharia dos Materiais |
| Ano: | 2017 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso restrito |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | This paper reports a systematic attempt of preparing concentrated aqueous suspensions (up to 0.3 wt.%) of different types of carbon nanotubes (CNTs) using Pluronic F-127 for developing ductile cementitious composites. Single-walled and multi-walled nanotubes, both pristine and functionalized, were dispersed in water using a short (1 h) and mediumenergy (80 W)ultrasonication process using pluronic at high concentrations (above critical micelle concentration, 1–5 wt.%) and also using sodium dodecylbenzene sulphonate (SDBS) for comparison purpose. The CNT suspensionswere characterized for agglomerate area, particle size, zeta potential, extractability and long-term storage stability for a period over 4 years. The optimum suspensions were used to fabricate cementitious composites and their fracture behavior was characterized. Experimental results suggested that the optimum pluronic concentrations (1% for 0.1% CNT, 5% for 0.2% and 0.3% CNT, all in weight percent) provided highly homogeneous CNT dispersion with very lowarea of agglomerates. The best dispersion qualitywas obtained with f-SWCNT/pluronic system, which provided very low agglomerate area (b0.5%), lower CNT bundle size, good quantity of well dispersed nanotubes (up to 50%) and excellent long term storage stability. Cementitious composites fabricated using SWCNT and f-SWCNT suspensions showed ductile fracture behavior and improvement in fracture energy up to 164%. |
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