Dispersivity of multi-walled carbon nanotube and its effect on the mechanical properties of MWNT/cement composite

作者：Luo Jian Lin^*; Duan Zhong Dong; Li Hui

来源：Nanotechnology and Precision Engineering, 2009, 7(6): 532-536.

• Aqueous media
• Bridging effects
• Cement matrix
• Cement paste
• Cement-based
• Cement-based composite
• Centrifugation methods
• Cetyltrimethylammonium bromide
• Dispersants
• Dispersivity
• Four-group
• Gum arabic
• Hydrated product
• Interfacial bonding
• matrix
• SEM image
• Sodium dodecyl sulfate
• TEM
• Triton X-100

Four surfactants (SAA) (sodium dodecyl sulfate (SDS), Triton x100 (Tx100), cetyltrimethyl ammonium bromide (CTAB), and gum Arabic (GA)) have been used as dispersants to measure the dispersivity of multi-walled carbon nanotube (MWNT) in aqueous media by incubation and centrifugation method. Four groups of MWNT/cement composites (MWNT/CCs) with 0.21% loading (by mass of cement) of MWNT and various SAA dispersions have been cast-mixed and the plain cement pastes (PCP) have been fabricared. Their flexural σfand compressive strengths σchave been measured, and microstructures of MWNT/CC with GA dispersion and PCP samples have been compared. Results show that, after incubation for 3 h, each of the four MWNT suspended solutions had the uniform blackness, yet GA had the best dispersion impact on MWNT as the solution retained stabilization till after 90 min at 5000 r/min centrifugation, and SDS had the worst effect as the solution remained stable only for 10 min after centrifugation. Compared with PCP, enhancement of σfand σcof MWNT/CC with GA dispersion is the maximal, up to 31.5% and 23.6% respectively, which reveals that MWNT has superior fiber pulling-out and bridging effect amongst cement matrix. TEM and SEM images also demonstrate that MWNT is well distributed in aqueous water and cement hydrated products, and there exists good interfacial bonding between MWNT and matrix.

• 出版日期2009